Cleaning Calipers

I took the calipers off my 07 GSXR 1000 with 9k on it and I am wondering if just cleaning the exposed piston surfaces is a good enough or if I need to take apart the calipers and remove the pistons completely. With no fluid in the calipers (removed brake lines) the pistons took a lot of force to push into the calipers which doesn't seem right to me.

 

Welcome to my world.

Clean them up. It can't hurt.

 

I soak mine in ATF transmission fluid for a couple hrs

Q

 

I usually take the brakes out and squeeze the pistons nearly out and then clean them with soap, water and toothbrush

 

you shouldnt have to push the pistons all the way out of the bores to clean well.
just lube the seals really well after cleaning

 

I pushed the pistons completely back into the bore so can I use compressed air to pop them out?

 

Also, if I take apart the calipers (split them) are there any sealant or gaskets I need to replace? Or is it just take out the bolts and put them back in?

 

Id use a mity vac with some clean brake fluid. Compressed air will likely blow a seal out

 

^I thought the Mity Vac created vacuum, but could you explain how I would use it to pop the pistons out?

 

mitv vac works both ways.
fill the caliper with fluid via the banjo hole... thread banjo in... crack bleeder screw and use the mity vac to blow air into the caliper to push the pistons out.

 

I've used compressed air before, just be careful. I don't remember the psi I used but I probably 30-40, in very small bursts from the airgun. Make sure to keep your fingers back.

 

Could you also: 1. remove the brake pads; 2. slide a block of wood in between the pistons; 3. the brake lever just a little pull, just enough to make the pistons contact the block; 4. clean/lube the pistons in that position; 5. remove the block and push the pistons back into the caliper?

 

What Rob said. Even less if it will work. If you just want to clean the gunk off the pistons some 409 and a toothbrush works well.

 

How easy should the pistons be able to move in the caliper? I had to press on them pretty hard with my hands to get them to go back flush. I'll try my air compressor tonight with some wood shims to catch every thing.

 

Not too easy, it should take some effort. Even when clean & moving freely, pistons don't move as much as one would expect they do.

 

or just crack the bleeder screw on the caliper to get the pistons back in place. Its alot easier than man handling them

 

Dont use compressed air if they were hard to push in. Once one of the pistons breaks free its going to fly out like a missle. If the pistons were free i'd say go for it but not with something thats already sticking on you.

 

I usually use the old pads and a screwdriver to block two from coming out and pump the brake lever to force two part way out ( far enough that clean puck shows). Then I clean them with 409 or something like that and a toothbrush.

 

It's easy, works and less chance of messing something up. If I remember correctly there was a video on OTT whereas Dave Moss also utilized this method.

 

It definitely doesn't hurt to split the calipers and give everything a good cleaning, especialy if any dirt or crap worked it's way past the dust seals and are wedged between the dust/oil seals and piston.

It was kind of detailed already, but the easiest way I've found to get stubborn (or really any pistons) out of the caliper is like this, the idea is to avoid the compressed air/piston missle approach.

1 - unbolt the calipers and remove the pads.
2 - lay an adjustable wrench in the center channel of each caliper where the rotor is normally sitting
3 - start pumping the lever until all the pistons push themselves out up against the wrench, the wrench is there to keep the faster moving pistons in place until the rest come out.
4 - pull out the wrenches and start pumping again, over a bucket or something until the first 1 or 2 start popping out (and fluid too obviously).
5 - unbolt the calipers from the hoses and split the calipers with the correct size Torx bit, I think the GSXR's use a T-40
6 - by now the pistons should be out far enough to wiggle out with your fingers or if need be cover the end with a rag and carefully wiggle them out with a needle nose plier
7 - now you take all the seals out carefully with a small flat bladed screwdriver. It is recommended to replace all the seals when rebuilding the calipers, but I've reused them on several calipers and had no issues. Just take them out very carefully so you don't gouge them, and wash them with hot soapy water and dry them off (NO brake cleaner or solvents).
8 - give the caliper bores and passages a good cleaning with brake cleaner if you like (assuming you have all the rubber seals out now). and blow everything out with compressed air so it's spotless. If you can't get the pistons completely clean of the caked on crud I've found that Scotchbrite cleans that shit off good without scratching the surface.
9 - finally coat all the seals and pistons in fresh brake fluid as you are putting them back in and reassemble.

I just did this whole process on a set of 04 GSXR-600 calipers that would barely move. After this they were working perfectly again.