Removing seized Kelsey Hayes pistons

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4spdragtop

4spdragtop

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1st off, I take no credit for this idea or "how to". The idea came up in another disc brake thread and hemi71x mentioned this idea.
Anyway, rusty KH calipers with seized pistons.
Set in calipers in evaporust for 24 hours, pulled out. Stuff works awesome.
I found a 3/8-24 fine thread bolt and threaded finger tight into brake fitting hole. Finger tight. Put caliper in vice and put an air nozzle with rubber tip 140 psi into other hole. Didnt budge, nada.
Then I remembered Jim mentioned threading a grease fitting in and using pneumatic/grease gun to pop them out.
Kinda self explanatory see pics.
Worked like a charm, thanks Jim!

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what happens when you energize them off the rotor? maybe you can C-clamp the ones that actually move to force the frozen ones out...
 
RAT ROD AL said:
Steve I get nothing on your links. Is it me ?
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For A Bodies Only Mopar Forum - Error


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there is no how to article about KH brakes yet, maybe he's amending it.
 
Link work at your end pishta?
Yes with c clamp. Once you have one piston most of the way out, put a c clamp in as a "stop". Grease gun again and other piston is forced out.
Then remove c clamp and wrestle other piston out. Repeat on other side.
I had to run a tap down the inside of brake fitting to match threads on grease fitting.
Hope that makes sense?
pishta said:
what happens when you energize them off the rotor? maybe you can C-clamp the ones that actually move to force the frozen ones out...
Click to expand...
 
Nope links dont work, but I figured out how to remove frozen pistons years ago. You can put a large socket open end around the one you want to pop and a smaller socket across the ones you dont want to move. Use the power of the MC. Grease gun is another option.

Have you "published" your how to article yet? Maybe its not public until you hit a button? Not in the index of brake articles either.
 
It says "awaiting moderation". May take a bit.
I was heating and prying got and compressed air for quite a while...nada. Took 5 minutes to rig up grease fitting and another 5 or 10 to remove 2 pistons.
 
Those cals I have are totally rusted, gonna soak in the evapo rust when it shows up then try your method. Will the grease gun screw right in or need an adapter ?
 
Dunno what happened to pics etc?? Here I reposted pics.
Used a 3/8 brake line fitting. Ran a rap down the inside of it that matched threads on small grease fitting. Essentially the fitting is now a bushing. Thread grease nipple in. Thread in a 3/8-24 fine thread bolt finger tight at opposite end to block in grease and force out pistons when pumping.
pishta said:
Nope links dont work, but I figured out how to remove frozen pistons years ago. You can put a large socket open end around the one you want to pop and a smaller socket across the ones you dont want to move. Use the power of the MC. Grease gun is another option.

Have you "published" your how to article yet? Maybe its not public until you hit a button? Not in the index of brake articles either.
Click to expand...

RAT ROD AL said:
Those cals I have are totally rusted, gonna soak in the evapo rust when it shows up then try your method. Will the grease gun screw right in or need an adapter ?
Click to expand...

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20190505_203853.jpg
 
Another advantage is its a bit safer using the grease gun and hydraulic pressure instead of compressed air.
 
4spdragtop said:
Dunno what happened to pics etc?? Here I reposted pics.
Used a 3/8 brake line fitting. Ran a rap down the inside of it that matched threads on small grease fitting. Essentially the fitting is now a bushing. Thread grease nipple in. Thread in a 3/8-24 fine thread bolt finger tight at opposite end to block in grease and force out pistons when pumping.




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I saw your "how to" thread and ok'd it. I see this is in Brakes now. :BangHead::BangHead: At least your information is out there. I forgot about the grease gin approach to force pistons out. I have never rebuilt calipers but These KH's are hard to come by. Getting the rust pits out of the housings would be the hardest. I imagine the rebuilders machine to a larger bore and use a different piston.
 
Air psi had ZERO effect at approx 140. TONS more psi AND effect with a grease gun lol, not sure if its safer or not but mission accomplished.
Mike, when I went to post info in "how to", I posted it to "steering/suspension/brakes" no idea how it got here, but like you said info is out that's the main thing.
Mattax said:
Another advantage is its a bit safer using the grease gun and hydraulic pressure instead of compressed air.
Click to expand...

toolmanmike said:
I saw your "how to" thread and ok'd it. I see this is in Brakes now. :BangHead::BangHead: At least your information is out there. I forgot about the grease gin approach to force pistons out. I have never rebuilt calipers but These KH's are hard to come by. Getting the rust pits out of the housings would be the hardest. I imagine the rebuilders machine to a larger bore and use a different piston.
Click to expand...
 
There are brake specialist that are able to save your brake calipers, master cylinders, and slave cylinders from rust pitting. They press in a bronze sleeve and machine it for your stock diameter, the last one I had done cost me about 20.00 a bore that was about 20 years ago. This link is such a place, more and more I am leaning towards this type of service again, getting junk at the out stores is getting tiresome.

Home | Brake & Equipment Warehouse
 
They have stainless steel sleeves for the bores for repairs or restorations. Vette owners like to keep their numbers calipers so this service is still going strong. They used 4 piston brakes too. although rebuilt loaded 4 piston calipers are still under $100 a side.
 
See, the hydraulic grease method works great, doesn't it, if you don't have the official factory Miller Special Tools from back in the dinosaur days.
Now let me add to this posting if i could.
If there is rust pitting in the caliper bores, that's not a big deal at all on the Kelsey Hayes style of brakes.
The piston "seal" is at the top of the piston bore, and not on the piston itself, like on the Bendix, or BUDD, disc brakes that Ma Mopar also used.
When the seal is on the piston itself, then yes the piston goes up on down in the caliper bore, but not unlike the Kelsey Hayes where the piston seal is "fixed" at the top of the bore and doesn't move around.
Kelsey Hayes had their s#%t together when they designed their brakes, not unlike the other two.
So what if the bore has some pitting to it.
It's not going to do anything.
Don't worry about it, loose any sleep over it.
What i do is get out my Dremel, with an 80 grit flap wheel on it, and lightly clean up the bores with that tool.
Works great, easy, peasy.
Guess if you don't have a Dremel, sandpaper, twisting around in the bores works, too.
But for me, my fingers don't twist, and manipulate, that well anymore, in my old age, so i use 'tools" to get the job done.
And one last thing, there is no such thing as an oversize piston on these disc brake systems.
Standard size(s) are what's produced.

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4spdragtop said:
1st off, I take no credit for this idea or "how to". The idea came up in another disc brake thread and hemi71x mentioned this idea.
Anyway, rusty KH calipers with seized pistons.
Set in calipers in evaporust for 24 hours, pulled out. Stuff works awesome.
I found a 3/8-24 fine thread bolt and threaded finger tight into brake fitting hole. Finger tight. Put caliper in vice and put an air nozzle with rubber tip 140 psi into other hole. Didnt budge, nada.
Then I remembered Jim mentioned threading a grease fitting in and using pneumatic/grease gun to pop them out.
Kinda self explanatory see pics.
Worked like a charm, thanks Jim!

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