Torch excitement round 2......Ding! (now some Knob Creek)

OK, last episode, powerdoc AKA the propane flash, caught the workshop on fire with a faulty torch. So I got a new one (at HF but go somewhere you can get a good one, this one doesn't want to light or stay lit...but I digress) and applied some heat to the brake caliper covers and voila! out came the covers.

The outer pistons came out with a minimum amount of fuss but then there were those inner pistons. I figured I'd start on the worst-looking one . Per suggestions of the forum, I used a liberal amount of various penetrating fluids then gave it a few judicious taps and I'm not sure it budged but then I applied some propane (AKA the blue wrench) then more propane and more propane and I still don't think it moved. Next move was to try and find something to grab the inner skirt of the piston. I had some 1/2" threaded rod and I cut 2 pieces about 6 or 7" long and then threaded a bolt onto each one and then used it like chopsticks with the nuts acting as a fulcrum then I took a big-ass crescent wrench and used it to pull the top end together pulling the other end out and against the skirt. Heat, pull a while, heat, pull a while etc. I could see a bit of motion at the interface of the piston and cylinder but it's not budging. Right now it's soaking in carb cleaner and I'll do the same stuff again tomorrow.

The second caliper got the same treatment but, being less corroded, it actually came out using the above technique. I have line on another caliper if the first doesn't budge although I' haven't drilled the outside yet.

On that line, what size hole do you drill on the outside of the caliper to drift out the piston? Is there a standard Zerk fitting that goes into the brake line thread if I try the grease pump out?

Any other suggestions?

Further suggestions are solicited.

Re: Torch excitement round 2......Ding! (now some Knob Creek

I just used a small one-handed grease gun and put it on the existing zerc/bleeder and pumped out my inner piston after leaving the thing to soak in kerosene for about a week.

Re: Torch excitement round 2......Ding! (now some Knob Creek

Never had this difficulty but have heard of drilling a hole behind the piston and pushing it out. Would really hate to do this to a caliper though. How about drilling a small hole in the piston then screwing a sheet rock screw into it and yanking it out? If this didn't work you could drill a bigger hole then tap it and screw a threaded screw in to push it out against the inside of the caliper.

Re: Torch excitement round 2......Ding! (now some Knob Creek

I'll let it soak for a while; my carb cleaner container is just right for the size of the caliper. Since the piston is scrap, I may try the hole in the piston and tap it and use a bolt to get it out. I'm not sure my taps are long enough to get into the depths of the caliper though. With that I think you'd have to be accurate in where the hole is as it'll knock the piston to one side and trap it if off center when pushing it out.

BTW, the Knob Creek is their 9 year old 120 proof stuff.....really nice neat or with a bit of ice.

Re: Torch excitement round 2......Ding! (now some Knob Creek

Darn Automobiles you pump pistons out before disconectin , if its functioning.
Throwing a piece of wood as a spacer between one piston & the disc , before its past the seal ,
so the second piston comes along too .

IF youve got movement , its all in the way you hold your jaw & little finger ! :shock:

Ive resorted to reassembling calipe , even using a G clamp to hold the free piston , and connecting to the hydraulics to pump the stuck one out. SO WE LEARNT to pump the pistons OUT , useing a spacer to limit movement , before disconecting lines .

A compressor sometimes works , but piston will likely escape like a shot from a cannon. So dont peer over it using Air . :lol:

Re: Torch excitement round 2......Ding! (now some Knob Creek

A possibility if the rest of the brake was ok, it's not, so it's doing all sorts of unnatural things we read about on this forum.

Re: Torch excitement round 2......Ding! (now some Knob Creek

You only need a hole big enough to poke a drift in to push our puck and yet not bugger the hole threads to re plug it with a allen set screw. Just locktie it back
in. I had Ms Peel's perfectly fine capliper and SS pucks drilled and tapped just for the simple ease to service in future. You have to on purpose inspect whole caliper to see the dark plug and even less so it painted to match, but I like the littler beauty mark in a plane face now. The first bike you go through this on you tend to savor the escalation of inventive extractors, on the next one you may reflect on simpler ways. Grease way is pretty cool but is a project of its own to set up if the front caliper ain't there for sealing the easy escape route. Rusted puck where it seals is trash anyway you do it.