Author Topic: Front wheel wont move! (Read 7406 times)

apostrophe28 · « **on:** April 16, 2012, 06:55:04 PM »

I recently replaced the seal on my front brake caliper, replaced the pads, and bled the system. Now my front wheel wont roll an inch even with the bleeder screw open $:-\$ ...any thoughts? K7 btw

DJ_AX · « **Reply #1 on:** April 16, 2012, 07:01:26 PM »

Did you adjust properly for the new pads?

And double.triple check you put it back together correctly!

apostrophe28 · « **Reply #2 on:** April 16, 2012, 07:18:37 PM »

Adjust what propperly for the new pads?
I took off the caliper, cleaned and replaced the seal, replaced and filled w fluid, bled.

SohRon · « **Reply #3 on:** April 16, 2012, 08:12:35 PM »

Quote from: apostrophe28 on April 16, 2012, 07:18:37 PM

Adjust what propperly for the new pads?
I took off the caliper, cleaned and replaced the seal, replaced and filled w fluid, bled.

you likely need to set the gap between the fixed pad and rotor: .006" is what's recommended, and it needs to be set before you bleed. If this gap is too large or small, it will lock up the whole system. Also, did you properly lube the caliper piston before installing? The backs and sides of the pad "pucks" need lube as well.

apostrophe28 · « **Reply #4 on:** April 16, 2012, 08:38:20 PM »

can you point me in the directions of instructions on how to set that gap?

crazypj · « **Reply #5 on:** April 16, 2012, 08:52:29 PM »

Loosen lock nut on fork leg, unscrew bolt through caliper arm (screw towards spokes)
put six thou feeler between inside pad and disc, tighten screw 'til it just slides, lock locknut

SohRon · « **Reply #6 on:** April 16, 2012, 10:35:27 PM »

Quote from: apostrophe28 on April 16, 2012, 08:38:20 PM

can you point me in the directions of instructions on how to set that gap?

http://forums.sohc4.net/index.php?topic=17788.0

bollingball · « **Reply #7 on:** April 17, 2012, 06:58:58 AM »

You don't have the service manual? You can not just through things like brakes back on with out knowing the spec. Do you have some sort of death wish?

Ken

Don R · « **Reply #8 on:** April 17, 2012, 07:19:38 AM »

I downloaded the manual and whenever I am working on a particular area I print it out. someday I'll have the entire manual out in the shop as well as here.
BTW, it's the bolt that goes through the spring and adjusts the swing on the caliper bracket.

crazypj · « **Reply #9 on:** April 17, 2012, 07:25:57 AM »

Quote from: Don R on April 17, 2012, 07:19:38 AM

I downloaded the manual and whenever I am working on a particular area I print it out. someday I'll have the entire manual out in the shop as well as here.
BTW, it's the bolt that goes through the spring and adjusts the swing on the caliper bracket.

Yes it is

Lil Red · « **Reply #10 on:** April 17, 2012, 08:03:56 AM »

give the poor guy a break...i have manuals and am always porking things up...the first time i took the front wheel off i put hub nou on facing inwards... The front wheel had 3/4 inch of slop....my first tought ...surely HONDA...wouldnt design it like this...it took me like another hour to figure it out...

I'm lefty...i look at a manual and then in my head have to turn the bike over to fiure out what way to turn the sump pan bolt.

some of us just aint as gifted.

apostrophe28 · « **Reply #11 on:** April 18, 2012, 09:02:00 PM »

FIXED: the plastic bushing between the piston and pad had fell and was binding up! bled and an easy fix!

new issues....extremely soft front brakes...have to clamp down 90% before i feel anything

crazypj · « **Reply #12 on:** April 18, 2012, 09:14:15 PM »

Spongy brake, bleed air out.
Air get trapped in M/C if it isn't level or slightly 'down' at hose fitting
Also, you don't pull lever all the way to bar, it's in service manual

Randy · « **Reply #13 on:** April 18, 2012, 10:01:32 PM »

The little hole in the calibar is plugged.. will not let the pressure back up to the cmaster

apostrophe28 · « **Reply #14 on:** April 18, 2012, 11:30:25 PM »

when I release the brake it will squire brake fluid 2" out of the m/c...so I think the return circuit is fine

LesterPiglet · « **Reply #15 on:** April 19, 2012, 01:28:02 AM »

I had problems getting a hard brake on mine after lots of bleeding. I pumped the lever several times and then taped it to the bars overnight. Next morning it was a lot harder...still not perfect tho.

trueblue · « **Reply #16 on:** April 19, 2012, 03:31:29 AM »

Quote from: LesterPiglet on April 19, 2012, 01:28:02 AM

I had problems getting a hard brake on mine after lots of bleeding. I pumped the lever several times and then taped it to the bars overnight. Next morning it was a lot harder...still not perfect tho.

+1 except I used a strip of rag, not tape to hold it nice and tight.

crazypj · « **Reply #17 on:** April 19, 2012, 06:55:09 AM »

Bungy lever to bar.
Put bike on side stand, turn forks full lock left , leave a couple of hours, turn full lock right and do the same. Tap brake lines with a screwdriver handle
When you remove bungy, hold lever and allow it to 'flick' out suddenly, it tends to pull air up and out of piston bore
You people are not shaking the bake fluid before using it? If you do you get 'micro-bubbles' in it which take at least 48 hrs to dissipate

Rookster · « **Reply #18 on:** April 19, 2012, 07:30:06 AM »

Quote

you likely need to set the gap between the fixed pad and rotor: .006" is what's recommended, and it needs to be set before you bleed. If this gap is too large or small, it will lock up the whole system.

Just to be clear on this. If you are using the spring tensioner then you need to make sure the pad isn't dragging on the disk. Other than that the pads will find their own gap based on the amount of fluid pushed into the caliper and the thickness of the disk. That little spring isn't going to retract your pads any more than the amount of fluid that flows back into the master cylinder. Many people (me included) don't even use the spring adjuster or screw. The caliper finds its place over the disk based on the gap between the pads. That gap is determined by the amount of brake fluid that acts on the piston. My guess is Honda tried to minimize brake squel by attempting to fix the back pad a certain distance away from the disk.

Scott

DaveBarbier · « **Reply #19 on:** November 17, 2013, 05:48:30 AM »

I know this is kind of an old thread but I think I'm experiencing the same thing. My '78 550's brakes worked before I did some work (new pads and SS lines), but now the pad won't return.

So after I installed new pads (I had to use a clamp and push the piston back into the bore a bit to fit over the disk) then I put the new SS lines on and bled the system and THEN I set the gap. But now when I squeeze the lever the pad stays locked and doesn't return. What exactly makes the pad return anyway? The MC? I'm about to go out and see if the return hole is plugged up. I lubed the pad but it's still tough to get it to slide in the caliper. Caliper seems smooth and clean but it's just a really tight fit. Can I lube the piston (haven't done that yet) by pumping the lever and having it stick out a lot then lubing the exposed sides or does that need a complete disassemble?

Also, unrelated...my MC seems to be weeping at the lever joint. It's just moist, not dripping. That's bad, right?

---
1978 Honda CB550K

HotCarl73 · « **Reply #20 on:** November 17, 2013, 08:10:17 AM »

Quote from: DaveBarbier on November 17, 2013, 05:48:30 AM

What exactly makes the pad return anyway? The MC?

The O-ring around the piston is square in cross section. When the piston is pushed out, it gets forced into a parallelogram shape. When pressure is released it goes back to square and pulls the piston back with it.

LesterPiglet · « **Reply #21 on:** November 17, 2013, 10:00:59 AM »

Most problems are with the little hole in the MC, make sure it is clean also. There are two holes in there.

DaveBarbier · « **Reply #22 on:** November 17, 2013, 10:13:06 AM »

Hm, ok thanks guys. I'll have to make sure both these things are free. But I'm replacing the MC anyway, but still want to see how it works.

Thanks

---
1978 Honda CB550K

trueblue · « **Reply #23 on:** November 18, 2013, 12:53:30 AM »

If you pull the lever all the way back to the bar while bleeding you will get a little fluid bypassing the piston in the master and cause a slight leak

. Won't affect the master cylinder but it will affect your paint if it gets on it

.

If the pad is tight in the caliper that won't be helping the pad retract. The other thing to do is remove the piston from the caliper and clean the oring groove. They get a build up of crud and corrosion behind the oring and this causes the piston to bind.

DaveBarbier · « **Reply #24 on:** November 18, 2013, 03:56:08 AM »

Quote from: trueblue on November 18, 2013, 12:53:30 AM

If you pull the lever all the way back to the bar while bleeding you will get a little fluid bypassing the piston in the master and cause a slight leak . Won't affect the master cylinder but it will affect your paint if it gets on it .

If the pad is tight in the caliper that won't be helping the pad retract. The other thing to do is remove the piston from the caliper and clean the oring groove. They get a build up of crud and corrosion behind the oring and this causes the piston to bind.

Interesting about the MC. I WAS bleeding for a bit and noticed the slight moistness right after. I wonder if my MC isn't leaking after all.

I lightly filed the pad and sanded it so the sides are super smooth. Added a little grease (I may have used too much before) and used a q-tip and lubed the piston after I pumped the brakes and had it almost falling out. Now the pad retracts somewhat. But I ordered a new seal for $9 that's coming tomorrow so I'll totally disassemble the caliper then. I have a feeling the caliper isn't terribly clean inside.

Just to be clear, when I let go of the brakes the wheel should spin completely free, right? A little drag isn't normal?

---
1978 Honda CB550K

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Author Topic: Front wheel wont move! (Read 7406 times)

bollingball