Author Topic: Brake caliper adjustment screw?  (Read 8228 times)

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Offline scartail

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Brake caliper adjustment screw?
« on: March 01, 2011, 10:05:24 AM »
Will a regular metric screw be okay to replace the caliper adjustment screw? Any special features needed? For a CB550K.

TIA.
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'76 CB550, was my daily beater... my cafe project...
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Offline Roach

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Re: Brake caliper adjustment screw?
« Reply #1 on: March 01, 2011, 11:02:15 AM »
yes you can aslong as you have the spring still and the bolt is the same length and grade
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Offline stueveone

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Re: Brake caliper adjustment screw?
« Reply #2 on: March 01, 2011, 12:48:24 PM »
Carefully notch out the end similar to the old one with a hacksaw or better yet dremel.

Offline scartail

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Re: Brake caliper adjustment screw?
« Reply #3 on: March 02, 2011, 08:13:11 AM »
Sounds good. Thanks!
'89 Hawk GT, newly acquired, daily beater...
'76 CB550, was my daily beater... my cafe project...
'72 Yamaha R5, newly acquired project... donated to my buddy...
'67 Suzuki T20, still working on her too... Currently in pieces...

Offline Frostyboy

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Re: Brake caliper adjustment screw?
« Reply #4 on: March 03, 2011, 04:09:52 PM »
You could of course get the right one for around $5+

http://www.davidsilverspares.co.uk/CB550K-1976-USA/part_70716/
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Offline mrrch

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Re: Brake caliper adjustment screw?
« Reply #5 on: March 03, 2011, 07:10:45 PM »
Better yet, just go to your local Honda dealer(if you have one)
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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #6 on: March 03, 2011, 09:06:01 PM »
 They are countersunk head, using wrong fastener will gouge up the swing bracket.

 Myself I dont use them, just get in the way for removing tires, pita when yoy have 2 discs..
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Offline ev0lve

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Re: Brake caliper adjustment screw?
« Reply #7 on: March 03, 2011, 09:10:51 PM »
Had my calipers on backwards so had to have something I could get a wrench on. If yours aren't then the stock would be better looking but yes, any old right size bolt will do the trick. If you're going to notch the end you'll want it a few mm over 50.
« Last Edit: March 03, 2011, 09:14:12 PM by Iggy »

Offline 754

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Re: Brake caliper adjustment screw?
« Reply #8 on: March 03, 2011, 09:22:55 PM »
 Alnost fprgot.. not only did I remove the screws, on my chopper, I cut off the threaded boss from the fork leg, then smoothed it off , before plating the lower legs..
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline scartail

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Re: Brake caliper adjustment screw?
« Reply #9 on: March 08, 2011, 04:24:29 PM »
Thanks for all the suggestions everyone.

There used to be a Honda dealer in my city, but no more. Then online 5$ for a bolt, and 10$ for the shipping... and the feeling of extra vaseline...

I'd rather bandaid it up for the time being. :)
'89 Hawk GT, newly acquired, daily beater...
'76 CB550, was my daily beater... my cafe project...
'72 Yamaha R5, newly acquired project... donated to my buddy...
'67 Suzuki T20, still working on her too... Currently in pieces...

Offline Steve F

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Re: Brake caliper adjustment screw?
« Reply #10 on: March 08, 2011, 05:37:23 PM »
Some say you can do without, but I would think it would be a good idea to keep.  The bolt is, among other things, keep the caliper/pad in near proximity with the rotor.  Lets say that the pad has some wear on it, and for some reason or another, the caliper gets bumped or pushed in and as a result, this pushes the pad/piston into the caliper, leaving a gap between the rotor and the pad.  The next time you go to grab the brake, you find that you have to pump it a few times to get the pad/piston back out to contact the rotor.  If you kept the bolt in place and adjusted, this would prevent the caliper from moving and pushing the pad in.
Steve F

Offline Kong

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Re: Brake caliper adjustment screw?
« Reply #11 on: March 09, 2011, 03:37:40 PM »
Take them off and throw them away - at best they provide fixed adjustment of a part that should be allowed to float free.  The only mystery about that part is why it is even there in the first place.  When its adjusted perfectly it accomplishes nothing that would not happen if it were not there at all, and when its out of adjustment it causes uneven brake pad wear.  Toss it.
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Offline Steve F

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Re: Brake caliper adjustment screw?
« Reply #12 on: March 09, 2011, 04:56:39 PM »
Take them off and throw them away - at best they provide fixed adjustment of a part that should be allowed to float free.  The only mystery about that part is why it is even there in the first place.  When its adjusted perfectly it accomplishes nothing that would not happen if it were not there at all, and when its out of adjustment it causes uneven brake pad wear.  Toss it.
Read the previous post....

Offline Kong

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Re: Brake caliper adjustment screw?
« Reply #13 on: March 09, 2011, 05:04:14 PM »
I did read the previous post, and dam near fell on the floor laughing.    ;D

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Offline Tintop

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Re: Brake caliper adjustment screw?
« Reply #14 on: March 09, 2011, 06:03:46 PM »
Some say you can do without, but I would think it would be a good idea to keep.  The bolt is, among other things, keep the caliper/pad in near proximity with the rotor.  Lets say that the pad has some wear on it, and for some reason or another, the caliper gets bumped or pushed in and as a result, this pushes the pad/piston into the caliper, leaving a gap between the rotor and the pad.  The next time you go to grab the brake, you find that you have to pump it a few times to get the pad/piston back out to contact the rotor.  If you kept the bolt in place and adjusted, this would prevent the caliper from moving and pushing the pad in.
Steve F

Lots of vintage racers run without the adjusters.  As 754 pointed out, they make it a PITA to remove the wheel with dual disks; and most racers run duals.  An example Turboguzzi had was in racing.  If the bike gets a head shake on a high speed straight, that can be enough to push the puck back.  And yes you will have to pump the brakes before the next corner. ;)
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Offline DavePhipps

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Re: Brake caliper adjustment screw?
« Reply #15 on: March 09, 2011, 06:18:31 PM »
I'm a bit confused. On my non floating anything FZR600 brakes there is no adjuster. when my pads were halfway worn there still wasn't much of a gap between pad and rotor. I also never had to pump the brakes a few times to get them working again.
Wy would this be?
I'm a bit loopy on cold medicine so I might be missing something obvious.
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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #16 on: March 09, 2011, 08:24:55 PM »
If your brake is dragging a bit, and you have to push it around or run out of gas, kick the caliper in with your heel or soft hammer..  Cant do that with the adjuster there, you have to unbolt it..

 Consider this.. those brakes were the dawn of Japanese disc brakes.. the collective minds at Honda were pretty smart, and did a good job.. but its a design NO ONE uses or that anyone ever copied.. stone age stuff..really..
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Offline MCRider

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Re: Brake caliper adjustment screw?
« Reply #17 on: March 09, 2011, 08:36:55 PM »
I'm a bit confused. On my non floating anything FZR600 brakes there is no adjuster. when my pads were halfway worn there still wasn't much of a gap between pad and rotor. I also never had to pump the brakes a few times to get them working again.
Wy would this be?
I'm a bit loopy on cold medicine so I might be missing something obvious.
I think on the FZR, a well respected sport bike, all four pistons/pads per caliper are "live" meaning driven by fluid and all 4 retract on their own. Consequently they are self adjusting. On our CBs there are 2 pads true, but only one of the pair is live, consequently the dead pad must be adjusted as it wears.
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Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #18 on: March 09, 2011, 10:03:41 PM »
I'm a bit confused. On my non floating anything FZR600 brakes there is no adjuster. when my pads were halfway worn there still wasn't much of a gap between pad and rotor. I also never had to pump the brakes a few times to get them working again.
I don't know much about the FZR.  But, I have yet to find a disc brake where the pads or caliper weren't allowed to float or track the rotor plane in some way.  There are different way to do it.

For the SOHC4, the spring on the adjuster pushes the stationary pad away from the rotor .006 inch.  The square section seal in the caliper withdraws the piston and piston side pad about .012 inch.  This allows the rotor to spin free of the rotor when the lever is released.
Without the spring and adjuster, the brake will always have more drag and wear than without, provided the caliper piston and seal are in proper working order. 

Those who don't understand how the the system is supposed to work, remove parts whose function they don't understand.

Race bikes can replace pads are frequently as necessary between races. They don't need no stinkin' longevity.  Things that may be appropriate for a race bike aren't necessarily good for a street bike.  In some cases, those same things are outright bad.

If your brake is dragging, you surely can kick it free even with the adjuster in place.  But, I would argue that such an occurrence warrants more brake attention than just kicking it.

Cheers,



Lloyd... (SOHC4 #11 Original Mail List)
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Offline fastbroshi

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Re: Brake caliper adjustment screw?
« Reply #19 on: March 09, 2011, 10:11:13 PM »
I'm pretty sure the FZR rotors are floating, held by rivets to their carriers.
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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #20 on: March 10, 2011, 09:24:39 AM »
 So now you can decide ..
 if 12 thou clearance from pad retracting, is too much, use the stock adjuster, and cut that in half (while in proper adjustment)
 Now if you want easier tirechanging on dual disc, or just dont want the extra harware, leave em off..
 I do know this.. either way works..
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My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

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Lost quite a few CB 750's along the way

Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #21 on: March 10, 2011, 10:22:45 AM »
if 12 thou clearance from pad retracting, is too much, use the stock adjuster, and cut that in half (while in proper adjustment)

Just for clarification.   Upon brake release, the spring on the adjuster pushes the caliper assembly to the right .006.  The caliper seal retracts the piston .012, which leaves a .006 clearance on each side the rotor, for no drag.  Without the adjuster, the caliper wanders from right to left as the rotor alternately contacts the pads, over bumps, in turns, etc.

Now if you want easier tire changing on dual disc, or just don't want the extra hardware, leave em off..

I don't believe the front axle can reliably be registered laterally with zero tolerance upon reassembly after a tire change.  Lateral de-registration would affect the disk to rotor clearance, necessitating a readjustment of the caliper clearance adjuster.  So, if you do any planning ahead in your work flow, you can loosen the jam nut on the adjuster to give extra clearance between pads for the rotor, making re-install easier.   After wheel install, then re-adjust inside caliper pad clearance and lock down the nut.  A couple strokes of the brake lever should get the pads positioned for normal riding.

I do know this.. either way works..
Yes, either way works.  But, I think the way it was designed to work is better for street use.  Perhaps the weight saved (an ounce?) without the adjuster, spring and locknut is better for racing.  But, I'd like to see that demonstrated with differential lap times, before and after the change over.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #22 on: March 10, 2011, 10:35:51 AM »
 why not just take the plunge, and finally get the shirts made.

 "STOCK is BEST, F@#K the rest"

 My shirt says,

 STOCK bikes are for the mASSes, not for Me!"
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My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

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Lost quite a few CB 750's along the way

Offline DavePhipps

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Re: Brake caliper adjustment screw?
« Reply #23 on: March 10, 2011, 11:01:38 AM »
I'm a bit confused. On my non floating anything FZR600 brakes there is no adjuster. when my pads were halfway worn there still wasn't much of a gap between pad and rotor. I also never had to pump the brakes a few times to get them working again.
Wy would this be?
I'm a bit loopy on cold medicine so I might be missing something obvious.
I think on the FZR, a well respected sport bike, all four pistons/pads per caliper are "live" meaning driven by fluid and all 4 retract on their own. Consequently they are self adjusting. On our CBs there are 2 pads true, but only one of the pair is live, consequently the dead pad must be adjusted as it wears.
Without any arguing, I would say this make the most sense.
Do I like the stock design, not much. There are better technologies out there that can be adapted to our bikes. If you want stock, fine, if not that's fine too. I was just more concerned with why it is like it is, and how it works.
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Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #24 on: March 10, 2011, 11:26:14 AM »
why not just take the plunge, and finally get the shirts made.

 "STOCK is BEST, F@#K the rest"

 My shirt says,

 STOCK bikes are for the mASSes, not for Me!"

I thought your shirt idea was pretty good.  So, I researched and found these below.

But, I have to wonder why you don't mount your engine inverted?  Doing it the stock way just makes you part of the mASSes, doesn't it?
For that matter, using ANY parts in a stock fashion, groups you right into those mASSes, doesn't it?

Cheers,  ;D ;D
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline Tintop

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Re: Brake caliper adjustment screw?
« Reply #25 on: March 10, 2011, 02:13:51 PM »
if 12 thou clearance from pad retracting, is too much, use the stock adjuster, and cut that in half (while in proper adjustment)

Just for clarification.   Upon brake release, the spring on the adjuster pushes the caliper assembly to the right .006.  The caliper seal retracts the piston .012, which leaves a .006 clearance on each side the rotor, for no drag.  Without the adjuster, the caliper wanders from right to left as the rotor alternately contacts the pads, over bumps, in turns, etc.

Now if you want easier tire changing on dual disc, or just don't want the extra hardware, leave em off..

I don't believe the front axle can reliably be registered laterally with zero tolerance upon reassembly after a tire change.  Lateral de-registration would affect the disk to rotor clearance, necessitating a readjustment of the caliper clearance adjuster.  So, if you do any planning ahead in your work flow, you can loosen the jam nut on the adjuster to give extra clearance between pads for the rotor, making re-install easier.   After wheel install, then re-adjust inside caliper pad clearance and lock down the nut.  A couple strokes of the brake lever should get the pads positioned for normal riding.

I do know this.. either way works..
Yes, either way works.  But, I think the way it was designed to work is better for street use.  Perhaps the weight saved (an ounce?) without the adjuster, spring and locknut is better for racing.  But, I'd like to see that demonstrated with differential lap times, before and after the change over.

Cheers,

Have to disagree here TwoTired.  Both the 550 and 750 front axle has shoulders on the 'nut' that goes on the left side.  Those shoulders align on either side of the fork leg.  Unless the axle spacers are re-installed incorrectly it will always position the wheel the same laterally.  As for just backing off the adjusters to faciliate wheel removal.  With dual disks this may be possible if the tire is the stock size.  However, if the tire / rim is oversize that will not create enough clearence for the tire to fit between the calipers.
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Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
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550/750 Filter Thread
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Offline fastbroshi

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Re: Brake caliper adjustment screw?
« Reply #26 on: March 10, 2011, 02:38:31 PM »
Eh Holes! I love it!!
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Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #27 on: March 10, 2011, 05:39:59 PM »
Have to disagree here TwoTired.  Both the 550 and 750 front axle has shoulders on the 'nut' that goes on the left side.  Those shoulders align on either side of the fork leg.  Unless the axle spacers are re-installed incorrectly it will always position the wheel the same laterally. 

Yes, there are shoulders.  But, neither the the fork leg's receptors, nor the axles shoulders are made to zero tolerance or an interference fit.  So, it won't position within, .000 in.  And, it really doesn't need to be.  The less tolerance a part is made to, the more expensive it is.  So, there is a trade off between cost and necessity.

Further, the the axle nut screws on the axle and that seating surface too, is made to a non-zero tolerance.  These parts are all from a bin, and rarely perfect in every dimension to the drawing//specification.  You CAN get lucky, but it is no way assured.  That is the purpose of tolerances.  The external tolerance of one part can never exceed the internal tolerance of the part it is being fit into.  So, some are a bit sloppier than others.  If the wheel was off center even .010, it wouldn't effect driveability, but it would affect the caliper clearance.  Fortunately, the adjustment is there to adapt easily.


As for just backing off the adjusters to faciliate wheel removal.  With dual disks this may be possible if the tire is the stock size.  However, if the tire / rim is oversize that will not create enough clearence for the tire to fit between the calipers.
OK, I can see that, sort of.  Many changes can have an unforseen ripple effect which in turn requires still more changes/modifications.
But then, I don't see why you need oversize rims/tires, other than for ogling.
If you need to swing the caliper outward out of the way, you can remove the adjuster completely during the tire change.  Yes, it is an extra step, but so was the dual disk conversion, and the adjuster definitely has benefits for a street bike as I have explained.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Tintop

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Re: Brake caliper adjustment screw?
« Reply #28 on: March 10, 2011, 06:15:37 PM »
OK TT, I'll call it a draw.  Yes there are manufacturing tolerances to consider, and these will vary from part to part.  However, if I always assemble the same parts & wheel, the same way as originally fitted and aligned, it will always position the same.  And yes if you change a part you are back to square one.

Oh, and yes, my street 550 cafe's reversed caliper dual disks have the adjusters fitted. ;)  Wheel removal is a PITA, but that's the trade off for the improved brakes.
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
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1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
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Offline scottly

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Re: Brake caliper adjustment screw?
« Reply #29 on: March 10, 2011, 06:32:36 PM »

For the SOHC4, the spring on the adjuster pushes the stationary pad away from the rotor .006 inch.  The square section seal in the caliper withdraws the piston and piston side pad about .012 inch.  This allows the rotor to spin free of the rotor when the lever is released.
Without the spring and adjuster, the brake will always have more drag and wear than without, provided the caliper piston and seal are in proper working order. 


A minor detail: The spring pushes the brake arm, NOT the pad, away from the rotor. The stationary pad "floats" in the housing, and is free to rub against the disc.
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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #30 on: March 10, 2011, 07:53:26 PM »
 EXACTLY..!!

 BOTH pads are on a radiused swivel pad, and can move in an arc..

 NO matter what anyone says, if the caliper seal retracts, say .012.. that is 12 THOUSANDS of an inch.. to those not in the know.. that is the thickness of 3 or 4 hairs off your head..
 So  the adjuster, set right can center that.IT DOES NOT..CANNOT prevent the pads from swivelling and touching..
 Its 12 thou.. at best you can center it.. does not mean it will stay there if brake expands in use.. Not everyone is capable of adjusting it properly..
 So ask ask you....... do you feel lucky ...........PUNK....
 ???
............at your wrenching skills..
.. or are you just anally going thru the motions while telling yourself you are doing something worthwhile..... ::)

 You decide, its your ride..
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Anti-Johnny

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Re: Brake caliper adjustment screw?
« Reply #31 on: March 10, 2011, 08:41:53 PM »
How is this screw intended to be adjusted. Not knowing how it works until now, I assumed that my squeaky brake was the result of the shop tightening this too much after putting my new tires on. I tried loosening it and tightening it some and cant tell a difference.
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Offline MCRider

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Re: Brake caliper adjustment screw?
« Reply #32 on: March 10, 2011, 09:01:13 PM »
How is this screw intended to be adjusted. Not knowing how it works until now, I assumed that my squeaky brake was the result of the shop tightening this too much after putting my new tires on. I tried loosening it and tightening it some and cant tell a difference.
A few definitions: The "live" pad, the one pushed by the piston is the A pad, the dead pad is the B pad.

Loosen the lock nut on the adjuster and turn the screw clockwise. Now you'll have clearance for the B pad. Push on the caliper so the A pad goes into the caliper a bit. Make sure the whole set up swings free on the pivot pin of the caliper mount. If not, you'll need to disassemble and clean the pivot. Use some waterproof grease on the pin and reassemble.

Get a 6 thou feeler gauge and put it between the B pad and the disc. Turn the screw counterclockwise drawing the b pad towards the disc until the gauge can be withdrawn from the pad/disc with the slightest of resistance. Hold the screwhead and tighten the lock nut. Pump the brake lever so the A pad comes into contact with the disc. Squeeze a little more and you'll see the B side draw into the disc. Release the lever and the spring will push the B pad away from the disc 6 thou and the A pad will retract into its housing a few thou. The wheel should spin free with the slightest sound of pads dragging.
« Last Edit: March 10, 2011, 09:03:41 PM by MCRider »
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Offline Anti-Johnny

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Re: Brake caliper adjustment screw?
« Reply #33 on: March 10, 2011, 09:27:08 PM »
How is this screw intended to be adjusted. Not knowing how it works until now, I assumed that my squeaky brake was the result of the shop tightening this too much after putting my new tires on. I tried loosening it and tightening it some and cant tell a difference.
A few definitions: The "live" pad, the one pushed by the piston is the A pad, the dead pad is the B pad.

Loosen the lock nut on the adjuster and turn the screw clockwise. Now you'll have clearance for the B pad. Push on the caliper so the A pad goes into the caliper a bit. Make sure the whole set up swings free on the pivot pin of the caliper mount. If not, you'll need to disassemble and clean the pivot. Use some waterproof grease on the pin and reassemble.

Get a 6 thou feeler gauge and put it between the B pad and the disc. Turn the screw counterclockwise drawing the b pad towards the disc until the gauge can be withdrawn from the pad/disc with the slightest of resistance. Hold the screwhead and tighten the lock nut. Pump the brake lever so the A pad comes into contact with the disc. Squeeze a little more and you'll see the B side draw into the disc. Release the lever and the spring will push the B pad away from the disc 6 thou and the A pad will retract into its housing a few thou. The wheel should spin free with the slightest sound of pads dragging.

Thanks MCRider! Ill be hunting down that gauge in the morning. I plan on rebuilding my caliper this weekend so this is good to know. My brake didnt start squeaking until I started messing with it, and so now I get to figure out what I did.
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Offline MCRider

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Re: Brake caliper adjustment screw?
« Reply #34 on: March 10, 2011, 09:48:09 PM »
How is this screw intended to be adjusted. Not knowing how it works until now, I assumed that my squeaky brake was the result of the shop tightening this too much after putting my new tires on. I tried loosening it and tightening it some and cant tell a difference.
A few definitions: The "live" pad, the one pushed by the piston is the A pad, the dead pad is the B pad.

Loosen the lock nut on the adjuster and turn the screw clockwise. Now you'll have clearance for the B pad. Push on the caliper so the A pad goes into the caliper a bit. Make sure the whole set up swings free on the pivot pin of the caliper mount. If not, you'll need to disassemble and clean the pivot. Use some waterproof grease on the pin and reassemble.

Get a 6 thou feeler gauge and put it between the B pad and the disc. Turn the screw counterclockwise drawing the b pad towards the disc until the gauge can be withdrawn from the pad/disc with the slightest of resistance. Hold the screwhead and tighten the lock nut. Pump the brake lever so the A pad comes into contact with the disc. Squeeze a little more and you'll see the B side draw into the disc. Release the lever and the spring will push the B pad away from the disc 6 thou and the A pad will retract into its housing a few thou. The wheel should spin free with the slightest sound of pads dragging.

Thanks MCRider! Ill be hunting down that gauge in the morning. I plan on rebuilding my caliper this weekend so this is good to know. My brake didnt start squeaking until I started messing with it, and so now I get to figure out what I did.
You're welcome, if you turned the screw and couldn't tell a difference, its likely the thing isn't swinging freely on the pivot pin. You shhould see the B pad move away from the disc immediately as you turn the screw.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #35 on: March 10, 2011, 10:16:50 PM »
How is this screw intended to be adjusted. Not knowing how it works until now, I assumed that my squeaky brake was the result of the shop tightening this too much after putting my new tires on. I tried loosening it and tightening it some and cant tell a difference.
A few definitions: The "live" pad, the one pushed by the piston is the A pad, the dead pad is the B pad.

Loosen the lock nut on the adjuster and turn the screw clockwise. Now you'll have clearance for the B pad. Push on the caliper so the A pad goes into the caliper a bit. Make sure the whole set up swings free on the pivot pin of the caliper mount. If not, you'll need to disassemble and clean the pivot. Use some waterproof grease on the pin and reassemble.

Get a 6 thou feeler gauge and put it between the B pad and the disc. Turn the screw counterclockwise drawing the b pad towards the disc until the gauge can be withdrawn from the pad/disc with the slightest of resistance. Hold the screwhead and tighten the lock nut. Pump the brake lever so the A pad comes into contact with the disc. Squeeze a little more and you'll see the B side draw into the disc. Release the lever and the spring will push the B pad away from the disc 6 thou and the A pad will retract into its housing a few thou. The wheel should spin free with the slightest sound of pads dragging.

Thanks MCRider! Ill be hunting down that gauge in the morning. I plan on rebuilding my caliper this weekend so this is good to know. My brake didnt start squeaking until I started messing with it, and so now I get to figure out what I did.
You're welcome, if you turned the screw and couldn't tell a difference, its likely the thing isn't swinging freely on the pivot pin. You shhould see the B pad move away from the disc immediately as you turn the screw.
Not quite.  The spring does not necessarily push the piston side pad back, especially if the seal is distorted or the piston sticking.  To set the stationary pad, back off the adjuster so it will allow the arm to swing inward, then push on the caliper against the rotor to force the piston pad back into the bore.  (Beware the fluid is going back up to the master.)  Now set the fixed pad clearance to rotor at .006 in, lock down the adjuster and recheck clearance.  Readjust if necessary so that after lock down, the inside pad still has .006 in clearance.  Depending on how far in you pushed the piston previously, it will take a pump or two of the brake lever to get it back into ready position.  This assumes the caliper is clean of all foreign sludge or hardened brake fluid and the piston isn't too badly pitted, which distorts the seal and diminishes piston/pad retraction.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
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Offline crazypj

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Re: Brake caliper adjustment screw?
« Reply #36 on: March 10, 2011, 11:18:06 PM »
With dual disks this may be possible if the tire is the stock size.  However, if the tire / rim is oversize that will not create enough clearence for the tire to fit between the calipers.

 Totally agree with this
 I ran Dunlop TT100's almost exclusively on 550, 4.10 x19 on WM3 rim.
It wasn't possible to get wheel out without removing caliper bolts both sides and 'splitting' calipers and letting all the air out to get it between mounting bolts
 Without the adjusters it's a right PITA to get wheel back in as one or the other would always swing' into wheel.
 I also noticed the brakes didn't seem as 'tight' with the adjusters removed so I guess the pistons do retract when riding.
 I used adjusters and re-set pads every few thousand miles (although pads were usually worn out by 4~6,000 miles)
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Offline TwoTired

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Re: Brake caliper adjustment screw?
« Reply #37 on: March 11, 2011, 12:41:21 AM »
BOTH pads are on a radiused swivel pad, and can move in an arc..
I guess you also threw away that nylon ring that keeps the pad in line with the rotor, too?

Nothing like throwing away parts because you don't understand what they are for.

It is 6 thou clearance not 12 thou.
Yes, a small portion of pad can/could contact the rotor.  But, it ain't the whole pad as the caliper swivels back and forth on its pivot.

But, it's ok, I "get it" that you just don't/can't "get it".  Do what you like.  I just hope beginners and those who wish to understand, will choose science and engineering over speculation.

Be Well!
Lloyd... (SOHC4 #11 Original Mail List)
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Offline 754

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Re: Brake caliper adjustment screw?
« Reply #38 on: March 11, 2011, 07:44:37 AM »
 This is what I tested feel free to list how many miles you tested yours.
 BTW the finned calipers  probably,did not use the plastic washer.

 I ran 2 discs drilled by me with calipers turned around. -3 lines I assembled myself. Later on I chromed the MC and calipers and cut the adjuster mounts off prior to chroming. No ill effects observed.. no noticeable drag if coasting..you can hear if they are dragging.
 Perhaps some of you enjoy the spongy feel of stock lines opposed to the firmer feel of  hardlines,, but I prefer the harder feel, and 2 finger braking, and the ability to easily chirp the front tire at 60mph..
 I ran mine for at least 20 thousand if not 30 or more, with no noticeable ill effects..

 You can put your time into fine tuning many areas of your bike, I prefer to concentrate on power and gas mileage..

  Keep in mind, if you adjust the brake incorrectly, it can drag, there are many things you can do to your bike that will make a bigger difference.. your choice..
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