Topic: SOFT front brake - i'm outta ideas...

[Franky]

Hi guys

I have read a gazzillon theads about the subject, but I can't seem to nail this one.

I recently decided to do some servicing on my CB550 frontbrake as it wasn't retracting as it should and dragging quite a bit. I had descent grip and stopping power.
I, of course, snapped the bleed screw and had to drill it out, do new threads and put in a slightly larger one. It seals fine with no leaks.

Now I simply won't get a firm grip or actually any grip at all. The best I can do, is about a centimeter with some resistance but it's still no prob to squeeze it down to the handlebar.

Here's what I've done so far:

- Took caliper apart, some gunk, cleaned it up (especially the groove behind the seal). Piston had a few minor pits but looked fine. Put in new Honda seal.
- Took MC apart, not much gunk, cleaned it up. Piston, the seals, etc. didn't look bad but I rebuilt it anyway with Honda kit.
- Tried bleeding the system the manual way for literally hours, but could not get any grip. No visible bubbles in the fluid coming from the bleed nipple. Used same techniques as shown here: Motorcycle Brake Bleeding Procedure from Sportbiketrackgear.com
- Tried using a vacuum system. Ran about 400 ml of dot5 fluid through.
- Did some knocking with the back of a screwdriver on MC and caliper to loosen any trapped bubbles.

Other info:

- The small hole in the MC is clear and I get squirts flying high in the air without the lid on.
- The new MC piston has a different 'o-ring' as you can see in the image. The rest of the parts that we're in there and the Honda rebulid kit were identical. Tried using both pistons - no grip.
- Checked for leaks at varius banjo bolts and for cracks, bulges on the hoses - all seem fine. Braided steel on top, regular rubber on lower part.
- The caliper piston moves nice and freely, retracts beautifully.
- The stopping power is there, it works, but obviously very weak.

Hope you can point me in the right direction 

[05c50]

The rubber cup on the mc piston marked as "new" in the picture, appears to be smaller then the old one. Maybe it just looks that way, but could it not be sealing correctly? I would try to separate the mc from the rest of the system (plug the hole where the line attaches) and see if the mc holds pressure.

...............Paul

[Kong]

That flat faced seal that goes in front of the piston, are you sure its not in backwards?  I've seen it happen more than once.  The flat face contacts the piston and the cupped face faces the return spring.

[Rio_CB750]

I know that for my 750, I had to do a "bench bleed" after my rebuild, no manner of normal bleeding would get the brakes right.

If photobucket worked, I could show you the pics, but basically, put a first length of brake hose on and dip the end into your reservoir and then pump. You'll see bubbles coming out, when that is clear, start putting it together down to the caliper making sure that you don't drip that crap on anything!  Maybe that will do it, good luck brother!

[Magpie]

Try tieing the brake lever back to the handle bar and leave it over night. If there's any air in the fluid it will make it's way up to the master and escape through the small hole as it's now open because the lever is back. It's worked for me several times.
Cliff.

[Kevin400F]

Slight mod to Magpie's comment......

Tying the lever back (assuming you were able to build pressure in the system) does help air migrate up to the master cylinder to be "burped" out of the small hole, but the hole is not open until the lever is released fully.  (When the lever is tied back, the seal cup inside the master has moved past the small hole.) 

Building pressure and tying the lever back squeezes any trapped air bubbles down to a fraction of their original size, which lets the bubbles sneak through fittings more easily.  After it sits overnight, turn the bars so the right side handlebar is pointing slightly upwards, slowly release the lever, and with the MC cap off, lightly cycle the brake lever a few millimeters, while watching for any air to be burped out of the small hole.

All this being said, the fact that one of the cups in the MC rebuild kit didn't match the original is a bad sign.  If the other seal cup (closest to the brake hose connection) is also "short" like the one in the picture, you will have excessive lever travel before you build pressure, and no amount of bleeding will change things. 

[Kong]

If the brake system has been put back together properly and none of the parts are bad then you won't have to go through any of those rituals.  There is a problem somewhere, it needs to be found and fixed.

Open up the bleeder at the caliper.  Put a length of clear plastic hose over it, one that fits tight.  Put the other end of the hose in a quart jar that has about an inch of brake fluid in its bottom.  Make sure the end of the tube stays submerged all the time.  Now fill your master cylinder and start pumping.  Do not let the master cylinder drop to less than 1/3 full, replenish the fluid as you pump it out.  It should immediately start pumping fluid through that tube.  Don't close the line when you let off the brake handel because if the pressure drops it can't suck any air into the system because the end of the tube is submerged.  Anyway keep on pumping until you've pumped about a half a quart of brand new brake fluid through the system.  Then close the bleeder and take the hose off.  There will be no air in the system after you have done that.  If it still doesn't work and there is no fluid leaking out of the system anywhere you may safely assume that your master cylinder is for crap and you might want to find another one.  Remember, a rebuild kit won't do squat if the bore of the master cylinder was pitted more than you were able to hone out - you did hone the master cylinder before you put new seals in it, didn't you?

[tlbranth]

I have a Goldwing which makes my 750 look pretty simple. On the Goldwing forum, brake bleeding is a popular topic because is virtually impossible to do on a Goldwing. BUT, the consensus there is that air likes to hang out in banjo bolts so successful bleeding includes bleeding the bleeding banjo bolts.
When I rebuilt my 750, I couldn't get any fluid at all through the MC. Once I finally got something moving though, the thing bled easily with standard bleeding technique.

[haill]

did you crack open the banjo bolt at the master cylinder after pumping the brake lever with the lever held to the bar?

[camelman]

I usually tap on the various pieces with the handle end of a screwdriver.  It helps dislodge bubbles.  I've also resorted to unbolting things and moving them around, such as the master cylinder and the stop switch.

Camelman

[HondaMan]

- The small hole in the MC is clear and I get squirts flying high in the air without the lid on.

That indicates air in the line somewhere.
When bleeding, here's a tip that helps: turn the handlebars to the side where the master cylinder is level first. Also, make sure the brake lines go ONLY DOWN from the master to the caliper. Sometimes a PO has installed a longer-than-stock upper brake hose and it snakes around, trapping bubbles...make sure the whole path between the caliper and master is UP. Then pull in the lever about 1" (as measured at the ball end) with a piece of wire, install a 3' long piece of hose on the caliper bleed bolt and crack it open, fill the master, and go have a cup of [tea, coffee, Jim Beam] and come back. Close the caliper bleed and check it (watch out for that squirt, brake fluid eats paint!) for grip. You may find that short strokes of about 1" on the lever now will let the tiny bubbles finish out.

[Franky]

Thanks a lot for the many replys. I really appreciate it!

@05c50, Paul: You're right. The new one looks smaller in the picture, but they are identical except for the positioning of the rubber in the middle. The idea of separating the MC makes sense. I just hope it ain't busted...

@Kong: I'm sure it does! I had both the Haynes and Shop Manual out when reassembling, so even a moron like myself would be hard pressed to #$%* it up :-) About the honing of the MC cylinder: I did clean it out. Not much gunk and no scratches or the like. I am worried that the MC could be crap though...

@haill: I did this to every banjobolt down the line!

@Hondaman: The upper part of the line is in fact quite long and winding - i'll look into your advice (and probably have the Jim Bean to calm down)...

[MADCB400F]

Mornin, looking at your PIC of the plungers the new shows you have the rubber seal still rolled inside out and not seated correctly in comparison to the old. Fix the seal before you do anythin else.

[Franky]

@MADCB400F

I'm sure I put the new rubber on the right way. As I said, the rubber itself and the positioning of it in the  Honda rebuild kit is slightly different to the existing one. The bump or groove on the MC piston that holds the rubber is different too. So, I guess my MC is not original or Honda made the slight alteration because it works better/easier to produce...?
In any case, the stopping power was there before and I tried both the old and the new MC piston afterwards with the same negative result.

Today I have time to mess with it again - hoping some of your suggestions will work. Thanks again guys. 

[fishhead]

Measure the diameter of the new and old pistons. Pictures may be deceiving, bit they do look like different sizes.

   I don't know everything, but the Honda master cylinders (US models) that I have seen with the plastic reservoir pictured were for the 75-77 GL 1000 Goldwing (they usually have a larger reservoir for the front, but the rear reservoir is smaller and fits on the front and look like what you have). The 75-77 GL master cylinders are 11/16 inch in diameter.

[Franky]

Just a quick update to let you know, that the MC is not busted.

I have a CB360 with good brakes so I tried swapping MC's. Result: the CB360's brake was still nice and firm, whereas the CB550 was as soft as ever - even with the 'new' CB360 MC installed.

[socalenduro]

when i replaced my lines i could pump and pump and pump....and it never firmed up... literally an entire bottles worth of fluid....
after taping every centimeter of the line to make sure there were no bubble i gave up and went to bed. came back the next day and re bled the system. i guess overnight all the bubbles made their way up...
have you let the system sit with fluid in it?

[Roach]

when i replaced my lines i could pump and pump and pump....and it never firmed up... literally an entire bottles worth of fluid....
after taping every centimeter of the line to make sure there were no bubble i gave up and went to bed. came back the next day and re bled the system. i guess overnight all the bubbles made their way up...
have you let the system sit with fluid in it?

+1 on that same thing happened to me with my 550 had to waited over night because i got frustrated cam back next day and started pumping again and it all worked out.

[ryani]

Another trick I have used on my dirt bike front brake is to bleed it and then if it's a bit spongy wire or tape lever back towards the handlebar and let it sit overnight.  It opens up the passage in the M/C to let the air bubbles escape.

[HondaMan]

Just a quick update to let you know, that the MC is not busted.

I have a CB360 with good brakes so I tried swapping MC's. Result: the CB360's brake was still nice and firm, whereas the CB550 was as soft as ever - even with the 'new' CB360 MC installed.

Then, it may be that the O-ring on the piston in the front caliper is not sealing like it should, and there may be a sticky brake puck there as well. If you just replaced the pads, make sure the paint is sanded off the edges of those pads (or the rust, if old) so they will move freely in and out.

[socalenduro]

it most likely air or a fast leak if you are not getting any build up in the lever...
if your pads were stuck the lever would still feel firm the front wheel just wouldnt roll.
and for it to not build up any resistance in the lever fluid would REALLY have to be leaking

[Franky]

PROGRESS!

1.
I did the sitting overnight with lever tied down to the handlebar trick and that helped quite a bit. Both instantly and when I'd bleed the thing I'd get tiny bubbles thru the bleed nipple. Did it a couple of times so far.

2.
Something must be bent in the fork or the caliper assembly. Even before Rotortiller suggested it (thanks a lot though  I saw that the brake pads wouldn't meet the rotor at a right angle. I added a washer on the lower part of the caliper-arm where one bolt attaches it to the front fork. That helped a lot! A much larger area of contact means much better braking.

3.
'Gaither' PM'ed me with his experience with DOT5 fluid. Slow lever action when bleeding - regular fast pumping will build tiny bubbles in the fluid

All in all I now have OK braking, but there's still some way to go I think. Maybe I'll try to get a hold of a giant hypo and try that out---

[FunJimmy]

When I purchased my first CB550, the PO had stripper the bleed nipple so badly that I knew it wouldn’t come out without snapping off in the caliper, but the brakes needed bleeding so I removed the caliper and pumped the lever until the piston was just about to fall out. Then I emptied the master cylinder reservoir and refilled it with fresh fluid before I pushed the caliper piston all the way back in again. You wouldn’t believe how fast the air was purged from the lines. I repeated this procedure a couple more times before remounting the caliper and the system worked perfectly.

It’s very similar to forcing the brake fluid through the bleeder up to the master cylinder, but you don’t need a hypo and there is no fluid spills to contend with.

[Roach]

When I purchased my first CB550, the PO had stripper the bleed nipple so badly that I knew it wouldn’t come out without snapping off in the caliper, but the brakes needed bleeding so I removed the caliper and pumped the lever until the piston was just about to fall out. Then I emptied the master cylinder reservoir and refilled it with fresh fluid before I pushed the caliper piston all the way back in again. You wouldn’t believe how fast the air was purged from the lines. I repeated this procedure a couple more times before remounting the caliper and the system worked perfectly.

It’s very similar to forcing the brake fluid through the bleeder up to the master cylinder, but you don’t need a hypo and there is no fluid spills to contend with.

wow that's really good info I will have to give that ago.  makes allot of sense.

[flybox1]

Hot air rises! 
i had a similar experience, and here's what i did. 
i tactically acquired my wifes hairdryer and w/ brake lever tied to handlebar and bars turned to the left,  i gently heated every component of my system.  paying closer attention to any transition, especially the brake light switch and banjo intersections.  i did this every 30 minutes for about 2 hours while i worked on other stuff on my bike. i was pretty surprised at the bubbles still coming out of the MC when i finally pumped it.

[singedebile]

Hot air rises! 
i had a similar experience, and here's what i did. 
i tactically acquired my wifes hairdryer and w/ brake lever tied to handlebar and bars turned to the left,  i gently heated every component of my system.  paying closer attention to any transition, especially the brake light switch and banjo intersections.  i did this every 30 minutes for about 2 hours while i worked on other stuff on my bike. i was pretty surprised at the bubbles still coming out of the MC when i finally pumped it.

i hadnt heard it before ..interesting idea, good thinking!

[Franky]

Hi there

Just wanted to let you know, that the main reason for the poor brake power was the misalignment i spoke of in a previous post.

I messed around with more washers and a bit of bending and it keeps getting better. It's fine for now. I think next winter I'll look into replacing the fork, brakes and all with something more modern.

Thanks for your all your help guys

[Oddjob]

I'm wondering if you've done what I did once and fitted the caliper incorrectly, was before I became a bike mechanic and the 500 was a new model bike back then so it wasn't that easy to find a person who actually knew a great deal about disc brakes on bikes. Anyway I'd installed the mudguard mount behind the caliper pin top mount, this made the caliper sit at an angle in relation to the disc, like yourself I got pressure but very little braking power, this kept getting better as the pad wore down at an angle to match the disc. I spotted it when I took the caliper off one day to check pad wear and started kicking myself for being so stupid, the piston pad was worn at about 30 degrees. Bought new pads, moved the mudguard brace to the outside of the caliper pin top mount and everything was fine afterwards.

[Oddjob]

When I purchased my first CB550, the PO had stripper the bleed nipple so badly that I knew it wouldn’t come out without snapping off in the caliper, but the brakes needed bleeding so I removed the caliper and pumped the lever until the piston was just about to fall out. Then I emptied the master cylinder reservoir and refilled it with fresh fluid before I pushed the caliper piston all the way back in again. You wouldn’t believe how fast the air was purged from the lines. I repeated this procedure a couple more times before remounting the caliper and the system worked perfectly.

It’s very similar to forcing the brake fluid through the bleeder up to the master cylinder, but you don’t need a hypo and there is no fluid spills to contend with.

wow that's really good info I will have to give that ago.  makes allot of sense.

2 problems with that Roach, firstly your supposed to replace brake fluid at least every 2 years, I do mine every year regardless, you need to do this because brake fluid absorbs water, whereas brake fluid has a high boiling point water does not, so water in your fluid is a very BAD idea, if it boils it turns to steam, you can compress steam unlike fluids, so you end up with no brakes. This method would leave unchanged fluid around the piston area where you really don't want it to be.
Secondly you stand a good chance of flipping the master cylinder seal back on itself, if you flip it back it no longer seals against the bore of the cylinder and thus no longer pumps fluid or it partially seals and you get horrible brakes as a result, the seal is designed to push forward thus pushing fluid down the lines, as the fluid comes back up the lines it flexs a little to allow this, as the amount of fluid going down and back it quite low it can cope with this, a large amount like your suggesting will stand a good chance of overpowering it's limited amount of flex thus flipping it back on itself, you can dismantle the MC but TBH who really wants to do that very often if at all.

[tlbranth]

Odd - I agree that brake fluid should be changed regularly and often and I'm probably wrong about this but the Japanese started using that concertina rubber thingy on top of the fluid waaaaaay back to prevent absorbtion of water. It seems to me that water would have a tough time being absorbed into such a system. But the fluid does get funky.

[Oddjob]

Water gets into every hydraulic system regardless of how you try and keep it out. The very hygoscopic nature of hydraulic fluid means it sucks this water up, you can't see it as the fluid absorbs the water. You cannot run the system in a vacuum, even the MC res cap has a breather hole in it, changes in air temp cause condensation to form on the inside of the MC, fluid splashing around inside the MC as your riding draws this condensation into the system. It's a very vicious circle and that's why every motor manufacturer recommends you change the fluid on a periodic basis, just changing half of it doesn't cure the problem, if the fluid around the piston is water saturated then your in big trouble, the first area of the braking system that gets hot is the pad/disc, this transfers into the caliper, very soon the caliper is very hot, try touching one after a run, you don't realise just how much your using the brakes and just how much heat your generating, a hot climate is even worse as the brakes take longer to cool down between each use. Once the caliper gets to a crucial heat level any water in the brake fluid will start to boil, as soon as it does your brake effectiveness will drop off rapidly, when it turns to steam the lever will come back to the handlebar as you'll be compressing the water in it's steam form.
Lastly, what's heavier oil or water? we both know it's water, so the water in the fluid will try to go to the lowest point of the system which will be the caliper/piston area, leaving that crucial area unchanged is a recipe for disaster IMO.
Not trying to preach here, just trying to enlighten members who may not know this and could be hurt or killed by that lack of knowledge

[TwoTired]

Water gets into every hydraulic system regardless of how you try and keep it out. The very hygoscopic nature of hydraulic fluid means it sucks this water up, you can't see it as the fluid absorbs the water.

Agreed.  (With the exception of silicone fluid which is out there, but not recommended by me.)

You cannot run the system in a vacuum, even the MC res cap has a breather hole in it, 

No sir, there is a belows in every MC for bikes I seen; certainly on Hondas.

changes in air temp cause condensation to form on the inside of the MC, fluid splashing around inside the MC as your riding draws this condensation into the system. It's a very vicious circle and that's why every motor manufacturer recommends you change the fluid on a periodic basis, just changing half of it doesn't cure the problem, if the fluid around the piston is water saturated then your in big trouble, the first area of the braking system that gets hot is the pad/disc, this transfers into the caliper, very soon the caliper is very hot, try touching one after a run, you don't realise just how much your using the brakes and just how much heat your generating, a hot climate is even worse as the brakes take longer to cool down between each use. Once the caliper gets to a crucial heat level any water in the brake fluid will start to boil, as soon as it does your brake effectiveness will drop off rapidly, when it turns to steam the lever will come back to the handlebar as you'll be compressing the water in it's steam form.

An interesting theory, for sure.  Water does enter the system through osmosis of and the seal membranes.  Mostly the adverse effect is compromising the corrosion inhibitors.  I don't know of any support for the "steam theory".  But, I would be willing to review test reports or other supportive analysis toward it's validity.

Lastly, what's heavier oil or water? we both know it's water, so the water in the fluid will try to go to the lowest point of the system which will be the caliper/piston area, leaving that crucial area unchanged is a recipe for disaster IMO.

Wait. Oil?  Where did that come from, and how did that get into the brake system?  The scenario you forward is only true for Silicone brake fluid.  DOT3, 4, and 5.1 all absorb the water and distribute it solution.

Not trying to preach here, just trying to enlighten members who may not know this and could be hurt or killed by that lack of knowledge.

I'm all for enlightenment, and am more than willing to share.  I sure would prefer to enlighten based on reality/factual info, though.

Cheers,

[TwoTired]

Most master cylinders have a bellows to seal the system from air. I've also seen fluid many years old still look like new. If the system is tight no worries about moisture at the master cylinder area. Storing the machine indoors along with fine weather riding is different than leaving the sucker out in the elements and driving in rain. A  blanket statement like you must change your fluid by this date is a bunch of BS. I'd be more concerned with  rubber wear debris contaminating the fluid over a long time. The brake fluid in my car is basically 12 years old and the thing still stops fine. The only fluid exchange happened 7 years ago when I replaced a wheel cylinder and had to bleed the thing. For that matter the coolant is original and being that it has over 250,000k it can self destruct for all I care.

The water can go through the seal membranes via osmosis.  The absorbtion rate is highly related to humidity levels and direct exposure to water contact.

Without testing the fluid to see how much water has been absorbed, you can't know if there is enough water to cause a problem or negate the corrosion inhibitors in the fluid.  So, it is far cheaper to simply change out the fluid periodically.
12 year old fluid may still be ok if it has been in an H2O deprived existence for all that time.  Then again, your brake system will still function with part of the internals corroded.  The point is to prevent that corrosion, especially in more complex ABS systems.

Since I'm on a roll...
I will caution you about engine coolant turning acidic.  I've seen it eat through an aluminum water pump housing in as little as 4 years.

I'm certainly no saint when it come to changing fluids per timetable.  But, I am aware of the possibilities and consequences, and can live with the guilt. 

Cheers,

[tlbranth]

Didn't mean to start a ruckus. I was just sayin'....

[Oddjob]

Water gets into every hydraulic system regardless of how you try and keep it out. The very hygoscopic nature of hydraulic fluid means it sucks this water up, you can't see it as the fluid absorbs the water.

Agreed.  (With the exception of silicone fluid which is out there, but not recommended by me.)

You cannot run the system in a vacuum, even the MC res cap has a breather hole in it, 

No sir, there is a belows in every MC for bikes I seen; certainly on Hondas.
As far as I can recall the master cylinder lid has a small pinprick hole.

changes in air temp cause condensation to form on the inside of the MC, fluid splashing around inside the MC as your riding draws this condensation into the system. It's a very vicious circle and that's why every motor manufacturer recommends you change the fluid on a periodic basis, just changing half of it doesn't cure the problem, if the fluid around the piston is water saturated then your in big trouble, the first area of the braking system that gets hot is the pad/disc, this transfers into the caliper, very soon the caliper is very hot, try touching one after a run, you don't realise just how much your using the brakes and just how much heat your generating, a hot climate is even worse as the brakes take longer to cool down between each use. Once the caliper gets to a crucial heat level any water in the brake fluid will start to boil, as soon as it does your brake effectiveness will drop off rapidly, when it turns to steam the lever will come back to the handlebar as you'll be compressing the water in it's steam form.

An interesting theory, for sure.  Water does enter the system through osmosis of and the seal membranes.  Mostly the adverse effect is compromising the corrosion inhibitors.  I don't know of any support for the "steam theory".  But, I would be willing to review test reports or other supportive analysis toward it's validity.
This is not a theory, literature is out ther on the web confirming that condensation does occur inside an hydraulic system, most components are metal especially the master cylinder, there is air inside the master cylinder, if the metal suddenly goes cold the water suspended inside the air will condense onto the metal, sudden altitude changes can cause this, we've all ridden somewhere where the air has suddenly gone very cold, areas like this will cause condensation to occur.

Lastly, what's heavier oil or water? we both know it's water, so the water in the fluid will try to go to the lowest point of the system which will be the caliper/piston area, leaving that crucial area unchanged is a recipe for disaster IMO.

Wait. Oil?  Where did that come from, and how did that get into the brake system?  The scenario you forward is only true for Silicone brake fluid.  DOT3, 4, and 5.1 all absorb the water and distribute it solution.
Ok poor choice of words but principle still aplies, the water suspended in the fluid will move down the system, gravity causes this. Saturated or contaminated hydraulic fluid boils at a much lower level than fresh fluid, typically at a level of normal braking temperatures, it's documented that old or low quality fluid is also susceptable to boiling at normal braking temps, it's called vapour lock. Don't believe me then google brake vapour lock. Brake fluid is designed to boil in excess of 300c, water as we both know boils at 100c, if water is suspended in the fluid what would boil first? boiling water turns to steam, steam can be compressed, hence vapour lock. 12 year old fluid is not advisable, it may still work but it will be contaminated, we've all seen black brake fluids, black fluid still works though BUT the hotter the brakes get the more chance of vapour lock, you may not drive hard enough to get to this level so you think everything is still fine, however like a ticking bomb it's just waiting for a set of circumstances to happen. Once you've crashed the fluid changes back from a vapour to a liquid making the cause of the accident difficult to determine.

Not trying to preach here, just trying to enlighten members who may not know this and could be hurt or killed by that lack of knowledge.

I'm all for enlightenment, and am more than willing to share.  I sure would prefer to enlighten based on reality/factual info, though.

Cheers,

As I've said google it, there are reams of factual info out there written by people far more enlighted than us, I don't profess to be an expert of brake fluid but I do believe it when the brake fluid experts say things will happen and provide all the evidence to support their theorys.

[Oddjob]

Didn't mean to start a ruckus. I was just sayin'....

LOL it's not a ruckus it's just a discussion and like a lot of discussions sometimes people can get a little OTT. I take no offense, if I'm wrong I'm wrong it's not the end of the world and it won't be the first time.

[Duanob]

I'd like to go back to the OP post about the mis-aligned caliper. Please clarify. The caliper assembly is supposed to pivot. There is an adjustment screw with a spring that you align the caliper pads to the disc for the easiest rotation of the front wheel. Did you adjust that screw?

[Franky]

@Oddjob: You nailed this one! The mudguard was indeed on the wrong side! The PO must have done this, and I didn't notice since it doesn't look wrong at all. Also, when I got the bike and replaced the pads, they were worn in the same way as you described. I swopped the position and got rid of the washers I added and it's OK now. Like you did ages ago, I too kick myself for being so stupid! I was so darn focused on all the bleeding! I even have the 360T sitting next to it with the correct assembly Jeeez!

@Duanob: Yes, tried adjusting the screw and all, but as you can tell from the above; issue solved!

Thanks for all your help and patience guys :-)

BTW: here's a site I keep about my CB550 build. It's in danish, but the dates on the left and pics are for all :-)
http://www.franky.dk/cbriders/?12.05.2011-nyt-saede-laves,86

[Oddjob]

RESULT!!!

It was only when you mentioned about adding washers that I remembered the mudguard problem. It's very easily done if your fitting the caliper mount after you've fitted the mudguard, I'm betting your not the only one on this forum who's experienced this so posting the solution may just prompt other members to check their caliper position.

Glad to help.