Anyone here have experience replacing caliper pistons? More specifically, does anyone have any tips/tricks/suggestions/voodoo for getting the dust jacket around the piston, seated in the caliper, and the piston inserted through the square cut seal? . Any one of these tasks (dust jacket around piston, jacket into caliper, piston into caliper) isn't so bad on it's own, but accomplishing all three...together...correctly... Please someone prove to me that it isn't a unicorn?
Also, the circular clip that only appears to hold the dust jackets of the rears-- am I right in that it is to be seated--like the dust jacket--down in the opening and over the jacket? Almost hidden from view by the lip of the opening?
I'm prepping parts from an '04 donor and figured I'd start with what I've got and upgrade when and where I can. I'm told that with Hawk HPS pads the '04's 2-piston/1-piston calipers are more than sufficient. That, coupled with the fact that one of the front caliper's dust jackets got torn, and I thought I'd try my hand at rebuilding calipers. I figure if I use them they'll look and work better, and if I don't they're worth more to the next person cleaned, painted, and rebuilt.
I haven't even ordered my kit yet and already I'm learning a lot; when I went into the auto parts store to find grease for the rebuild and explained to the clerk that I was rebuilding calipers he actually said "Wow. No one does that.". Then, a mechanic friend said that the go-to practice in professional garages is to order new calipers over troubleshooting. He told me that by the time you've found and fixed the problem on a caliper, the garage could order, sell, and install the replacement parts twice.
By the time I've built the caliper, I'm pretty sure you could mine the ore and cast the molds for new parts.
I rebuilt my 06-07 WRX calipers. Probably a little different from yours. I ordered the seal kit from rockauto.com. It was really easy. Just coat the seals and piston in brake fluid and they slide easily.
I started to rebuild, and then discovered what a cost of re-built and painted calipers cost.....no contest. The re-build parts cost was getting too close to the cost for a completely re-built unit. Same OE brand (Tokico), nice red paint, new hardware all around. I think my front 2004 calipers in red were $75ea after the core charge. I used EBay vendor BrakeOverstock or something like that. I can send you info if you are interested. Attached are photos of my fronts and rears.
Not to try and sway you away from re-building! I think it is great to re-use when you can. My units were far enough gone that all the parts (pistons, seals, clips, bolts, etc) needed major overhauling....not worth it for me. Yours may very well be much better. They will look great either way!
Looks like you got 2-piston fronts and rears for those prices too. Perhaps I should do some internet-snooping/shopping. Thank you.
I'm trying to save on whatever I can because I had the unfortunate timing of deciding to build a car the same year my wife and I bought our first house. (Boo hoo boo hoo).
Could you give me a real quick breakdown of what your process was for putting new pistons in? I've got the square cut seals in, I'm just trying to figure out the best order for piston into jacket, jacket into caliper, piston through seal, etc.
I should add here: I've been lubricating the rubber and the piston itself pretty liberally and have found that it will only slide past the square cut seal with some pretty serious leverage. That was almost one of my initial questions, but I've seen both: pistons that slide right into place, and others that require a pretty herculean effort.
Oh yeah, I just ordered speed bleeders ($35 for 4 calipers and 1 for clutch). Have read they make bleeding a simple one man job. Might be worth considering! Some people swear by them. (www.speedbleeder.com)
My calipers are two piece, and there are some o rings between them so I did those first. I put the seals on the pistons and pressed them in using wood blocks to help distribute load. After the were in past the seals, but not all the way, I added the boots and circlips, then pushed the pistons in the rest of the way. If any pistons have any oxidation on the sides, replace them. If the pistons are super tight, put them in the freezer for a half hour, and bake the calipers at 200 or so. They should go in easily then.
My calipers are two piece, and there are some o rings between them so I did those first. I put the seals on the pistons and pressed them in using wood blocks to help distribute load. After the were in past the seals, but not all the way, I added the boots and circlips, then pushed the pistons in the rest of the way. If any pistons have any oxidation on the sides, replace them. If the pistons are super tight, put them in the freezer for a half hour, and bake the calipers at 200 or so. They should go in easily then.
Hindsight--this response will undoubtedly prove invaluable--thank you. I figured a little oxidation on the pistons wouldn't hurt--now I'm not taking the chance. Apparently braking is "important" [citation needed]
The freezer/oven trick is brilliant. Thanks again, all.
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Originally Posted by ben1272
