Took my winter tires off my pick up today. When I swap seasonal tires, I make it a habit to service my brakes. Make sure everything is moving free and what not. In spring, I clean and lube the caliper pins. This year, the lower rear ones were stuck, so I cleaned and put silglide on them. I pulled off the front wheel, and needed new pads, so I popped off the caliper. I started the truck to cut the wheel so I could get a better view. Then I had a brain fart, and decided to pump the brakes so the rear calipers would engage the pads. As soon as I pumped the brake, I knew what I had done as I felt my foot go towards the floor. The lower piston popped, but the outer boot held it in place. I backed off the bleeder, carefully put it back in, losened the outer boot to get rid of the fluid, did my brake job, gave it a quick bleed, done. I have rebuilt many wheel cylinders, and master cylinders over the years, but never touched a caliper. What are the chances that it will never leak on me?
50/50?
Calipers aren’t bad to rebuild but often a new one is as cheap as the kit! Same with wheel cylinders. Chinese junk most of the time, any of the Oreilly’s master pro parts are usually a short lifespan crap coming over from Covid land. I won’t use their house brand unless I’m in a jam.
If the piston wasn't rusted it should be fine.
I didn't even look it over. The outer boot held it in place, and it didn't even spill a drop of fluid. It was all the way out of the cylinder because I had to move it around to get it back in. Once I got it back in place, I used a pick to unseat the boot, and drain the fluid that came out. Re seated the boot, and who's your father.....
Probably fine. Hell most of the pistons aren't even metal anymore.
I think the 50% are gonna win. I'm gonna watch the master cylinder to see if it goes down, but I think it's leakin. Hoping it's just some fluid I missed in the boot. New caliper is not that expensive, but I hate spending money for being stupid.
worst thing about calipers is when you find a rusty piston or one with scoring. Done everything from small motorcycle ones to those on 65 ton off-highway trucks and they are all pretty much the same, motorcycle ones are a bit lighter! Cleaning the rust/corrosion out of groves is the biggest part of the job.