What's the easiest way...

[yamaha1300rider]

Dear all

A year ago I removed my front calipers (for the first time in 4 years - and regretted leaving it so long) and was shocked at the crud on the pistons. I cleaned as best I could with a toothbrush and brake cleaner but realised that there is a small area on each piston where the toothbrush will not reach and a cloth will not clean well enough.

This year I had another go and the problem is the pistons are impossible to turn clockwise without a small tool with rubber or plastic jaws which will grip the pistons and yet not scratch them. The alternative is to blow out the pistons, clean up the mess of the brake fluid and rebleed.

So my questions are:

1. How are you other guys dealing with the cleaning of the pistons?

2. What tool is small enough to turn the pistons and not scratch them?

3. What is the cleanest way of draining the brake fluid (and point of drain) if the pistons are to be blown out

4. Has anyone replaced the seals - they cost a fortune!! Goodness knows why as the rear caliper seals are dirt cheap

TIA for your thoughts

 

[FJRPierre]

Last time I did it, I forced the pistons out further than normal by removing the pads, inserting some thinner material instead and pressing on the brake lever. Then using string etc, I flossed the pistons down to the core. To loosen the pistons and reinsert the pads, I cracked the bleeder nipple open to lose the pressure, pryed open, inserted pads, bleed the system. Seemed to work for me.

 

[yamaha1300rider]

String, now that's a novel idea - would never have thought of that for cleaning. Thanks Pierre

Anyone figured out how to rotate the pistons in situ?

As the seals are so prohibitively expensive, has anyone removed the existing ones, cleaned out the grooves and, coated the seals in red rubber grease and put them back without problems?

Cheers

 

[yamaha1300rider]

Bump!

Pierre and I can't be the only ones to have tackled this chore <_<

 

[ohiofjr]

If the pistons are corroded then the bore in the caliper prob has issues as well. Usually better to do it right than do it over. Seals can't be much compared to a hung caliper eating the rotor. I have had my brakes apart just to check, found mild corrosion,cleaned up piston and bore w/dremel polishing wheel, put it back together w/old parts, were no problems.

 

[racer157]

Having rebuilt motorcycles for 35 years, there are various ways of removing the pistons. The first way is to remove the calipers one at a time then remove one of the brake pads and leave one in. Pump the brake lever slowly and the pistons will move out clamping the single pad. Now you can remove the last pad and you should be able to remove the piston with your hands. If you need to you can use hot water to help expand the metal of the caliper . When you remove the pistons you can clean them using tooth paste and hot water. If the surface of the piston is corroded so much that you can catch a finger nail in the surface replace the piston. The next step is to carefully remove the seals from the caliper body. A tool can be made from a bobby pin. The key is to not cut or tear the seal because in most cases you can use the original seal again. You will probably find that on the back side of the seal you will have a deposit of a white powder like substance which is; a residue of aluminum sulfate, magnesium sulfate and calcium sulfate. You can remove this by simply using your thumb nail under a stream of hot water. The next job is harder. The same residue will be found in the groove the seal was removed from. To remove the the residue from the groove , again hot water and a tooth brush may work fine. In some very severe cases I get used dental tools from my local dentist who normally throws them away anyway and carefully remove the build up which is why the brakes were not able to work properly in the first place. Now that you have cleaned the pistons and caliper coat the seals with brake fluid and reinstall them in the groove they came from. Coate the piston with brake fuid and reisert the piston in the hole it was removed from. It should now slide easily into it's hole. It is not as hard as it sounds and when you take the time to clean these very important parts you will have taken a very important step in maintaining you bike at a very high level. You may experience better milage ,better acceleration and of course better brakeing. Good luck and feel free to e-mail me at [email protected] if you need further help.

 

[yamaha1300rider]

I have had my brakes apart just to check, found mild corrosion,cleaned up piston and bore w/dremel polishing wheel, put it back together w/old parts, were no problems.

I thought the pistons were chrome and a polishing wheel would damage it. No?

Thanks for your ideas

To remove the the residue from the groove , again hot water and a tooth brush may work fine.

Don't we have to be careful using water anywhere near brake fluid as it is hygroscopic?

Thanks again

 

[ohiofjr]

I do not mean a wire dremel whell, rather one of the cloth ones w/a fine compund only a little coarser than rouge. Water does not matter because after reassembly you are going to completly change the brake fluid anyway. You do change the fluid every year anyway?

 

[yamaha1300rider]

Thanks for clarifying, ohio

 

[squeezer]

I do not mean a wire dremel whell, rather one of the cloth ones w/a fine compund only a little coarser than rouge. Water does not matter because after reassembly you are going to completly change the brake fluid anyway. You do change the fluid every year anyway?

On my other bikes, I changed brake fluid every other year and thought I was ahead of the game. Is every year recommended for the FJR?

 

[yamaha1300rider]

On my other bikes, I changed brake fluid every other year and thought I was ahead of the game. Is every year recommended for the FJR?

Here in uk it's every 2 years