Dogma's Caliper Piston PSA

[Dogma]

When using compressed air to remove the piston from a brake caliper, not only should you keep your fingers out of the caliper, you should make sure the piston is not aimed at a storm drain.

[hikermikem]

Hmmmmm... I wonder how you know that??

[buckeyemike]

retrieve

I had to reach behind a freezer with a magnet for one of mine

[catbed]

may i ask why you were doing that in the street?

[Old Colt]

Is this what ebay is for, to get replacement calipers for old bikes.

[Nessism]

Is this what ebay is for, to get replacement calipers for old bikes.

So you take off one set of old calipers and install another equally old set?

[Headphase]

I got one out the other day using compressed air at the local garage. It shot into the air, smacked off their ceiling (while everybody was covering their heads) and then bounced off under a lathe out of the way.
How we laughed.

I won't be going there again, they all point and laugh now

I need to get my own compressor, since piston firing could be an olympic sport in a few years, got to get some more practice in.

[Baatfam]

I just did two calipers yesterday...no problem...

Just wrapped a shop rag around it first...pop...caught in the rag....

[Old Colt]

So you take off one set of old calipers and install another equally old set?

Yup, but for those keeping bikes stock it is a supply for replacing hiding parts such as the ones that go scurrying behind lathes or cannon fire into storm drains.

[Dogma]

questions...

Why was I doing this in the street? Because that's where I park my car. (Wifes' in the driveway, the GS in the garage.) My only compressor is a little portable job that I keep in the car, and it runs off the lighter.

Replacing old caliper with another old caliper? The parts bike had two calipers, one had a good piston. All four caliper bodies were nasty and in need of cleaning.

[Headphase]

Well, to answer the 'replace old with old' question, I bought an old rear caliper off of ebay, so I could clean/repair one, while the other was on the bike.
Once done, I have a perfect rear caliper on the bike, a spare (off of the bike) and a bit more knowedge as to how brakes work.

This strikes me as a mighty efficient way to learn, it's inexpensive, there is little to no bike downtime and if it all goes horribly wrong it's not the end of the world.

Anyway, I'm off to fire brake pistons at something, I can only sympathize with Dogma, I bet your fingers are sore , hehehehe

[Dogma]

Anyway, I'm off to fire brake pistons at something, I can only sympathize with Dogma, I bet your fingers are sore , hehehehe

Nah, fingers are fine. Someone else around here got one squished though. The pick I was using to dig junk out of the seal grooves might be sore, but not my finges.

[82Shafty]

I just did two calipers yesterday...no problem...

Just wrapped a shop rag around it first...pop...caught in the rag....

I'm a fan of the rag method. Of course not many shops rebuild calipers anymore; so one isn't truly receiving a thorough brake job.

[Dogma]

I just did two calipers yesterday...no problem...

Just wrapped a shop rag around it first...pop...caught in the rag....

That's what I'll probably do next time. For now, my compressor options require both hands, so I can't hold the caliper in my hand. If I had to do it again, I think I'd at least put it in a cardboard box.

Bottom line, this procedure really needs at least as much care and consideration as a pellet gun.

[Old Colt]

Personally when a stuck piston comes free. It has allot more energy than a pellet gun. You do not want it hitting any tender parts or anywhere on your face or eyes. I have a good friend going into his second year of operations trying to keep an eye from the impact of the tip of a 2X4 that spit out of his table saw. He did have protective eyeware on. The injury was massive for a little chunk of wood.