A bit of torch excitement!! Round 2....ding

So the caps on the brake calipers won't come off; used WD40, Kroil, and a bit of the hand impact and nothing, nada, bupkis, not a crack. So, as many on the board advocate, use a bit of propane. The first went easily with a remarkably little amount of heat applied around the edge of the cap; the second took a bit more applications and I turned the torch down and set it down and all of a sudden the thumb screw side of the torch bursts into flame. For a reason unbeknownst to me, I decided to take the fire extinguisher with me and fortunately the fire went out promptly but there was a steady stream of propane from that end of the torch so it's outside now and when it cools down I'll remove the head and promptly recycle it! The good thing is that the 2nd caliper then came apart easily! It's been some years since I'd used that torch head and I guess a seal dried out and cracked. I guess I'll need to see if it was from Sears so they'll replace it.

Now to clean up that damn powder from the extinguisher!

Re: A bit of torch excitement!!!!

Flamin' 'eck! :twisted:

Re: A bit of torch excitement!!!!

P-doc, I've had that happen a fair number of times on little hand held bottle torches to bigger tank and hose jobs. Its more annoying task delaying than dangerous unless you are on dry hay and can't drop it or blow out pretty quick. I think its aggravated by the bottle contracting refrigerating letting off vapor. Flame can appear just below the torch nozzle, the valve stem or the bottle threads. Might not do it again till using a while. Be aware of it and start shopping for another torch head if can't solve this one by telfon tape and snug up. Get Permanent dedicated exhtingisher or 3 to keep where you fetter so can't blame thoughtless laziness to have on have IMMEDIATELY just in case. Hi heat is part and parcel on old cycles. If something don't come off at first cold attempt I don't try again till about glowing and smoking hot. So things like you learn to just start plenty hot before first attempt. Congrates on the caliper success, as you obviously didn't have a very frozen one thank goodness. Bad ones can need pushing from behind after drilled a port to do so and I've had to have some drilled and tapped for bolt to pull it out through the rusty crusties. I consider working with flame more exciting dangerous than my flashy bullet drilling Ok.

Re: A bit of torch excitement!!!!

Well, at least it is a Craftsman so I'll get a new one. The brake fluid, if one could properly call it fluid (well I guess it was wet) was a rusty mess. One of the outside pistons moves a bit, the other not. The pads were, of course, also a rusty mess but came out without any persuasion. Sprayed a bit of the WD on the bores to keep the innerds wet. Can you torch the pistons in the cylinders to loosen them? ? use a pipe expander to remove the pistons?

Addendum: Looking at the Harbor Freight site and they have a reverse vise grip.....it expands ....at least I'll have a way to grip the outer piston, not sure it'll be long enough to get the inner one. News at 11...

Re: A bit of torch excitement!!!!

I tried torching mine but ended up drilling and tapping and a lot of prying! Good luck

Re: A bit of torch excitement!!!!

Can you torch the pistons in the cylinders to loosen them? ? use a pipe expander to remove the pistons?

Click to expand...

Yes and some times its best to heat the stuck object rather than its surrounds to frist expand it then as heat flows out it contracts and expands the surrounds. Don't know about being able to fit pipe expander in this case. Its a waste to replace with stock steel pucks or guess what will happen again. get the SS versions with the next owner in mind too. A big supermagnet or 2-3 can be used to pull on pistons or add mass to get out the old slam/bam- thankyou mam method. Don't know it the SS version are SS enough to not be magnetic too, but shouldn't get rusted in place in future. The real bugger is if bores not pitted in corrosion to seal again.

I almost broke a big vise off its mounts and my knee tackling a frozen caliper cap so always anti-seize em now and heat the snot out of and wait a bit for heat to flow to caliper before trying to turn off, so far been easy that way after the horror of first repair on pre-Ms Peel.

Re: A bit of torch excitement!!!!

Addendum: Looking at the Harbor Freight site and they have a reverse vise grip.....it expands ....at least I'll have a way to grip the outer piston, not sure it'll be long enough to get the inner one. News at 11...

Click to expand...

Powerdoc - thanks for mentioning this! This is why it is SO IMPORTANT TO PERUSE THIS SITE AT WORK. :mrgreen: :mrgreen:
I can not only use this (Harbor Freight SKU #97556) at home, but I have a tooling application here at work where this will be very useful: I'm gonna go pick one up one tomorrow!
Mello

Re: A bit of torch excitement!!!!

I can't see how an expander anything can get out the back puck unless you intend to push it out the back of the solid caliper. If you could explain your mechanical logi i'd sure like to catch up to it.

Re: A bit of torch excitement!!!!

Well, not having a clean part to look at, I was assuming that the piston had skirts that I could grab onto. Is the piston just a puck?

Re: A bit of torch excitement!!!!

powerdoc said:

Well, not having a clean part to look at, I was assuming that the piston had skirts that I could grab onto. Is the piston just a puck?

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Just a puck.

brake-caliper-teardown-yes-with-pictures-t5458-45.html

Sorry about the missing pictures. I'll see if I can get that fixed.

Fixed all the pictures I could. Enjoy.

Re: A bit of torch excitement!!!!

actually the fluid side of the piston has a skirt which of course doesn't help retrieving the outer piston. I guess I'll try the whack and smack method first for the inner piston. Which genius at Lockheed thought of this arrangement where the inner piston had no outer access? I bet he got a raise for figuring out a cheaper way to do it.



It's pretty easy to whack the outer piston in; How much room is there usually behind the inner piston to whack it?



Now a theoretical braking question: Since the pad is touching only the peripheral skirt of the piston, are we supposed to assume that the backing of the pad is sufficiently stiff to make the pressure in the center of the pad the same as the edge??????? Has anyone designed a piston that truly is a puck (or just reversing the pistons in the bore) so that the pad is hit evenly with the piston?

Re: A bit of torch excitement!!!!

powerdoc said:

actually the fluid side of the piston has a skirt which of course doesn't help retrieving the outer piston. I guess I'll try the whack and smack method first for the inner piston. Which genius at Lockheed thought of this arrangement where the inner piston had no outer access? I bet he got a raise for figuring out a cheaper way to do it.



It's pretty easy to whack the outer piston in; How much room is there usually behind the inner piston to whack it?



Now a theoretical braking question: Since the pad is touching only the peripheral skirt of the piston, are we supposed to assume that the backing of the pad is sufficiently stiff to make the pressure in the center of the pad the same as the edge??????? Has anyone designed a piston that truly is a puck (or just reversing the pistons in the bore) so that the pad is hit evenly with the piston?

Click to expand...

Remember, engineers don't engineer towards rusted out pistons. With a clean bore and a decent piston it comes out no problem. Read my link. Just a touch of compressed air and it came out.

Look at the pad again, you think that will distort?

Re: A bit of torch excitement!!!!

Right now, the inner piston doesn't seem to be budging with a mallet and a drift; Scotty, more Kroil!

Re: A bit of torch excitement!!!!

Don't blame Lockheed blame failing Norton for not using SS pucks and pistons, ugh.
Kroll is a joke in tough cases like yours. ATF/acetone or candle wax. I had to put on a stack of super magnets to add mass to bump out the 1st bad frooze up one, over days of swearing. 2nd one I took to machine shop which drilled and tapped the already ruined puck to suck it out via the drill press tap already screwed in.
Older method is drill back and drift out. Some get grease are air pressure to push out.

I suspect the pad back plate is plenty stiff when supported around it rim to press pad pretty darn equal on disc, especially with the factory hydraulic ratio, which is stil plenty good enough once you open up the factory m/c restrictor and hose good and stiff yet.

Re: A bit of torch excitement!!!!

powerdoc said:

Right now, the inner piston doesn't seem to be budging with a mallet and a drift; Scotty, more Kroil!

Click to expand...

Did you try heat again?

Re: A bit of torch excitement!!!!

That's next; since Sears wouldn't give me a new torch for the one that leaked and caught on fire I now need to get a new one; interestingly, no torch Sears sells is labelled Craftsman. I used to buy all my tools there. I'd wait for the twice a year sales in the catalog (remember the Sears catalogs?) and order a bunch of stuff. My first serious tool set (bought when I was 16) is still up and running. But their paradigm has changed.....I wax nostalgic.

Anyhow, I'll get a new torch tomorrow and try some heat and some gizmo to grab onto the skirt to rock it out.

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Yes Sir back when we were still waiting for the flying cars in everyone's garage I too had Sear Craftsman tool set and still do but hardly look there anymore. Pawn shop, swap meets or Walmart and online are my shopping places. They used to make real motorcycles in England back then too.

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Btw Nitric acid will not harm Al so can dribble acid to flow around the pluck so it turns hard swollen rust into soft reddish mush that can be wiped or flushed away and repeated till nothing holding puck in to prevent it knocking right out. Still a flesh burn risk of course but slower acting flesh burn than friction or flame type that thin gloves can't protect from.

Re: A bit of torch excitement!!!!

What concentration of nitric acid? How hard is it to get?

Re: A bit of torch excitement!!!!

powerdoc said:

What concentration of nitric acid? How hard is it to get?

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Nitric acid can affect the caliper as it's an alloy, not pure aluminum. Patience is cheaper than a new caliper.