New quest for those that can help. I have a binding calliper on the front right and although I can thake them off and take to a garage to be done I fancy doing the job myself. So, I understand that using compressed air would be the preferred option but I dont have that at my disposal, so I am considering doing what the manual suggests, and to push them out by depressing the brake lever. So, my problem is, 1) the mess, & 2) how to get them out without damaging the pistons. Has anyone attempted this and what problems did you encounter? Any help would be much appreciated.

 

I used this method on the rear caliper of my bike.

1. I used 2 transparent food/freezer bags which were quite thick and they stood upto the job with no mess.

2. the pistons were well worn and were being replaced anyway but I couldn't see any sign of recent damage that I could blame on this method.

I did find getting the pistons out together took a bit of work and holding back one piston by hand was a bit tricky, I think I used a plastic screwdriver handle wedged between the caliper and piston on the free piston. Overall it worked but be prepared to replace the pistons - I think the Haynes manual recommends both piston and seals. Also if a piston is sticking it is usually because it is worn - looks like rippling on the surface of the piston.
Good Luck

PS my bike is a 1990 L-model - not combined brakes.

 

What year is your bike? I have a '94 that I de-linked. I the de-linking process you have to pull the pistons out. I used pump-handle pliers with a rag on the pistons. Twisting while pulling them, they come out easy. My feeling is that you can't hurt the pistons if you are careful.

Back to the year, the linked breaks have 6 pistons. There are 4 different sizes. I know that the two lower left are the same size as one of the ones on the right side. The upper left is unique and the three on the right side are all different from each other. I just replaced a seal and had to figure out what size to order for the lower right side.

I think that all three in the rear are different also, or two that are neighbors are the same.

 

Thanks for the imput, will give it a go at the weekend if I can get time. Will let you know how I get on.

 

Its an 87 f-h, and there are two pistions on each calliper. I'm intending to do both at the same time, but only the right is showing signs of binding, but not enough to heat the discs or pads up yet.

 

Hi,

I have replaced the seals on both the front and back of my 1990 FL model. It was quite easy, with no real mess. Here's what I did:

1) Remove one caliper, taking the brake pads out first

2) This bit is easier if you have someone to help. GENTLY and SLOWLY squeeze the brake lever and you will see the pistons start to move out. If one piston comes out first, use the wooden handle of a hammer, or similar to wedge between it and the caliper body until the other one catches up

3) Keep pumping until both pistons are nearly out. It is REALLY IMPORTANT that they come out together. As they are nearly out, you will see some brake fluid leaking from around their bases. At this stage you should be able to rock them too and fro by hand. Put a bowl under the caliper and one last squeeze of the lever should see them pop out. Make a note of which piston came out of which bore so you can put them back intheir original places. NO MORE SQUEEZING or you will decorate your garage wall with brake fluid. The fluid will gently dribble out of the caliper into the bowl.

4) On mine, corrosion of the alloy caliper had got behind the outer dust seal and was causing it to bind on the piston. Thios seal was shredded. The pistons were fine, but I polished them up a bit with Solvol anyway

5) Scrape away the corrosion from the groove the seal sits in, clean out all the debris and refit new seals

6) Soak the pistons in brake fluid and press them back into their bores. If you can press them back in by hand then everything is fine

7) Refil the master cylinder with fresh brake fluid and refit the caliper and pads, after washing off all the spilt fluid

8) Repeat on the other side and the rear

9) Bleed the brakes

10) Take each caliper off again in turn (after removing the pads again) and get your helper to pump the lever until the pistons are NEARLY out again. Now push the pistons back by hand. If you have done the job right, they will slide back in with only moderate force

11) Recheck brake fluid levels and off you go

In all, it took me about 3 hours to do all three calipers and now I have no more binding brakes! Good luck

 

Great to read a how to . Thought I would check my front brakes as they seem to be sticking on after being sat a while. Had to knock off the caliper ! The seals etc seemed OK no major corrosion. But couldn't put the caliper back on , couldn't push the pistons in enough . Stripped it down and found a jelly like gunge behind the pistons which wouldn't allow me to push the pistons back far enough to refit the caliper. Cleaned it all up and refitted new seals. Now the caliper falls back into place. . Just the left side to do later as I'm old an my back hurts