Cleaning brake calipers - Need a little help

[mpb218]

Hey all, so I've noticed my brakes squeaking (newer pads, high quality) and put it up on the centerstand to see if the brakes were retracting. I could only get about 1/4 of a free spin on the wheel, so I decided to clean the pistons off. I took off the left front brake, the wheel still didn't spin freely, the right front was holding it up and riding on the rotor. I then took that off and took all the pads out and gave the brake a few squeezes to get them out for a good cleaning.

Here's the potential problem. When doing this, one of the pistons came OUT totally. I don't know if it is supposed to do this, I don't know if this is a serious issue or I can just clean it and put it back in. Any ideas/advice?

Appreciate it.

 

[mpb218]

Update - Shoved that sucker back in, bled the brakes, things seem to be working fine.

 

[TownsendsFJR1300]

Yamaha recommends replacing the brake seals every TWO years. You can usually go longer than that but if you only have a 1/4 turn after cleaning, it's likely times for new seals.

With new seals, assembled with brake SPECIFIC GREASE, you'll easily get 2 full turns and your brakes/rotors will last a lot longer. An air compressor is a BIG HELP with the dissassembly as the pistons are usually very sticky in the bore

Popping the piston back in is pretty much what you'll be doing for each caliper but X 4 for each side. Theres one dust seal and a regular seal with each piston. 2007 models and up use 4 pot pistons/calipers

I found using brake specific brake grease for the seals and pistons that I like is Permatex:
[ame="http://www.amazon.com/Permatex-24110-Caliper-Brush-Top-Bottle/dp/B000HBNV6W"]Amazon.com: Permatex 24110 Ultra Disc Brake Caliper Lube, 8 oz Brush-Top Bottle: Automotive[/ame]



You can get smaller tubes at your local automotive store for cheaper. The bottle posted above will last my lifetime. It makes assembly MUCH easier the pistons don't tend to stick near as much(just use as little as possible). New rubber seals also allow the pistons to move more freely than hardened up seals

 

[mikw73]

As an alternative to an air compressor, there's also a way to use a grease gun to fill the caliper with grease and force the piston out. The downside to the grease method is that you then have to clean the caliper. In either case, you'll want to have something holding the pistons even so they're all forced out. It seems like one always wants to come out first, and then you've gotta find a way to get the others out.

 

[mpb218]

Thanks TownsendsFJR1300 and Mikw73.

I'm usually pretty good with the regular maintenance schedule, but the brake seals are one thing I have never done. I'll order some seals and get on it, I appreciate it.

 

[TownsendsFJR1300]

You can always put a spacer (wood?) inbetween the pistons so they all come out almost to the end, then pluck by hand.

Swapping the seals isn't difficult, you'll likely have more time into bleeding them. A real fine DENTAL PICK helps getting the actual seals out. Put the new ones back in by hand, (shouldn't need a pick).

I also found IF using the air compressor, a very short stout piece of hose (I used air shock hose) cut on an angle attached to a the end of an air blower fits nice and tight into the cavity of the caliper and will shoot the individual piston out. If doing this, put a rag just outside the piston as it WILL pinch your finger(s) (don't ask)...

BTW, On my 07, they started dragging (not as bad as yours, about 3/4 a turn) at about 6k miles. I took them apart and just cleaned and greased the pistons (original seals) and re-assembled. While doing a quick wipe of the bike this am (12,700 miles on the clock), with the front wheel in the air, it free spins about 2.25 full turns. Next time I'll replace the seals...

 

[FinalImpact]

PS - don't anyone be temped to scotch brite the pistons or use sand paper on them. They need to spotless clean as does the caliper. Wash them in hot water and dish detergent after all the major grime is off. But again, no scratches, nics, burrs, dents, pits as all of these things will destroy the seal and cause it to leak.

Products like Scott recommends (above) work great for assembly and sometime twisting the pistons into place is better than trying to force them straight in. If it EVER ends up being a fight to get a piston back in the bore, pull it back out and inspect everything to make CERTAIN you don't pinch or roll the inner seal. This isn't a part you want to have fail. . .

 

[mpb218]

PS - don't anyone be temped to scotch brite the pistons or use sand paper on them. They need to spotless clean as does the caliper. Wash them in hot water and dish detergent after all the major grime is off. But again, no scratches, nics, burrs, dents, pits as all of these things will destroy the seal and cause it to leak.

Products like Scott recommends (above) work great for assembly and sometime twisting the pistons into place is better than trying to force them straight in. If it EVER ends up being a fight to get a piston back in the bore, pull it back out and inspect everything to make CERTAIN you don't pinch or roll the inner seal. This isn't a part you want to have fail. . .

Ah geez who in their right mind would?? lol these are precision machined pieces... I appreciate the looking out though. I wouldn't do that, but someone who would might come across this thread and learn otherwise.

If there were any burrs or such, I would get a new piston, simple as that. It would wreak havoc on the seal.

 

[mpb218]

Update - Shoved that sucker back in, bled the brakes, things seem to be working fine.

Update to the update: I was feeling froggy today and took apart the calipers to check out all the pistons and seals.

1. Compressed air is almost a necessity, I don't think I could have gotten the pistons out without it.
2. A wood spacer when using the air is handy so one doesn't fly out and you lose compression.
3. Yeah, I got pinched the first time.

One of the pistons (the side that was dragging) was all but welded in there. Took me awhile to get it out, it had some thick buildup on it. I cleaned all the pistons with brake fluid and a state of the art, lint free medium (a sock). I also cleaned off the seals and gave 'em the once over, they seem ok (I will change them at a later date though, probably next pad change).

I put it all back together, bled the brakes and the wheel now spins alot better. Previously I could only get a 1/4 to 1/2 free turn on it, now it's around 3 full turns and the squeak is gone.

I appreciate the help!

P.S. - I can definitely see how it would be tempting to use an abrasive pad on the pistons, that stuff is like a rock. I let them soak in fluid for a bit and it came off alot easier.

 

[FinalImpact]

P.S. - I can definitely see how it would be tempting to use an abrasive pad on the pistons, that stuff is like a rock. I let them soak in fluid for a bit and it came off alot easier.

Not that I recommend this, but a rag soaked in ATF (Auto trans fluid) works great at desolving build up as its very high in detergent. ** DO NOT USE IT ON RUBBER ** !!!! Or cast iron. Great for aluminum and anodized parts. **WASH REPEATEDLY with hot soap and water to remove ALL traces of oil!!**

Glad that worked out! PS - if you must reuse a seal, put it back in the same bore with the same piston facing the same direction it was when found. Not the dust seal, but the pressure seal. Frankly if you have them apart, replace the seals! It just good practice!