Calipers Dont Seem to Fit

[Adler]

So my wheels werent turning well on my '79 gs550 and I decided to tear down the calipers and change the brake fluid. I ran into a stuck piston problem but thats not the focus of this thread. I managed to push both pistons in all the way and decided to try putting the calipers on like that, just to see how it fits. I can barely get it on, and when i do one of the pads is always rubbing the wheel. Shouldn't i have maximum clearance on both sides? the pistons are all the way in...

 

[Calvin Blackmore]

pad oriented correctly?

You sure you got the pistons fully seated?

My bike is a PITA to get the new pads on even when I have the pistons conpressed its like there is a bit of a cushion of fluid that wants to push the pads together almost indescernibly

I have disconnected the brake line before in order to get em in
bleeding can be a pain theough afterwrds

got any pics
we like pics it makes letterman seem nicer

 

[Adler]

Tomorrow I will feed you guys some pics, just the way you like 'em.
Thanks Calvin

 

[Adler]

here is my lovely caliper;

and a view of the rubbing pad;

The calipers are totally full of air as i had them pretty much completely apart.

 

[jwhelan65]

Did you have the rear wheel off?

 

[Adler]

never took the rear wheel off, but i cant say the same thing for the previous owner... though I kinda doubt he did

 

[Calvin Blackmore]

this is the calipers on and tight?

awful lot of sapce on one side

try remvin and retightening the bold
though im unsure if you could skew them during install

you could be getting no effecive braking with the pad that far off they just glide normally


looks like the one with the gap may havce gooten cocked sideways

 

[TheCafeKid]

First, you should grease the slider pins there with some caliper/brake type grease. Take care not to get any on the pads. Secondly, they're always going to touch a little. Especially new pads. But, did you clean and rebuild the master cylinder? If you didn't clean it all out, debris, rust etc will collect in the fluid return port and prevent the pressure from backing off. This will create a problem similar to sticking pistons, but it will get worse and worse every time you hit the brake till it simply boils the fluid and smokes your rotor and pads.

 

[sparki]

there's no mention that the caliper was stripped and cleaned... just that the piston was pushed in.... i suggest that there is a large buildup of crud behind the seals and that they need stripping, cleaning and new seals added.

.....from what i read they've not been bled yet have they.

strip n clean first

 

[Adler]

First, you should grease the slider pins there with some caliper/brake type grease. Take care not to get any on the pads. Secondly, they're always going to touch a little. Especially new pads. But, did you clean and rebuild the master cylinder? If you didn't clean it all out, debris, rust etc will collect in the fluid return port and prevent the pressure from backing off. This will create a problem similar to sticking pistons, but it will get worse and worse every time you hit the brake till it simply boils the fluid and smokes your rotor and pads.

Where is this alleged fluid return port? I can't seem to find it...

there's no mention that the caliper was stripped and cleaned... just that the piston was pushed in.... i suggest that there is a large buildup of crud behind the seals and that they need stripping, cleaning and new seals added.

.....from what i read they've not been bled yet have they.

strip n clean first

I did mention that I took them completely apart at the end of the post with all the pictures.

 

[sparki]

Where is this alleged fluid return port? I can't seem to find it...



I did mention that I took them completely apart at the end of the post with all the pictures.

fair enough.... how did you clean out the grooves and did you put new seals in? also, the caliper doesn't look as thopugh it has it's mount bolts in... is that the case?

 

[Adler]

fair enough.... how did you clean out the grooves and did you put new seals in? also, the caliper doesn't look as thopugh it has it's mount bolts in... is that the case?

I didnt put new seals in, as it wasnt leaking before. I am in the process of using electrolysis on one of the pistons that had some corrosion near the top and some evaporust on one half of the calipers. They werent all that bad, but i figure it cant hurt to make them perfect.

I may get new dust boots but that wouldnt really affect my issue.

 

[sparki]

I didnt put new seals in, as it wasnt leaking before. I am in the process of using electrolysis on one of the pistons that had some corrosion near the top and some evaporust on one half of the calipers. They werent all that bad, but i figure it cant hurt to make them perfect.

I may get new dust boots but that wouldnt really affect my issue.

ok... were the seals removed and any crud behind them cleaned out?... also, what happens when the mounting bolts are put in as they don't appear to be on in the pics

 

[Steve]

never took the rear wheel off, but i cant say the same thing for the previous owner... though I kinda doubt he did

I would hope that SOMEONE, SOME TIME in the past has removed the wheel.

If not, DON'T RIDE THAT BIKE until you can get new tires installed. :-\\\

.

 

[Adler]

ok... were the seals removed and any crud behind them cleaned out?... also, what happens when the mounting bolts are put in as they don't appear to be on in the pics

Im cleaning the crud behind the seals now, why would that make the pads rub the wheels?

I would hope that SOMEONE, SOME TIME in the past has removed the wheel.

If not, DON'T RIDE THAT BIKE until you can get new tires installed. :-\\\

The tires definitely need to be replaced, they are pooched. I just havent gotten to that part of the restoration yet.

 

[sparki]

Im cleaning the crud behind the seals now, why would that make the pads rub the wheels?

it may not make a difference if the pistons were FULLY pressed in BUT it will make a difference when you try to use them as they will stick... old, dried out or damaged seals will do the same thing.... also going back to my 2 previous times of asking.... have you bolted the caliper back top the hanger yet to get it correctly alligned?

if the pistons are fully in the caliper, the wheel correctly installed, and the caliper bolted up to the hanger, with old pads..... there is no way it could be as tight as your picture suggests.....