Kelsey-Hayes 4 piston brakes question

[Captainkirk]

Trying to clean up and re-seal my KH disc brake calipers and finding all four pucks on each caliper are stuck. I tried the usual trick of trying to blow the pucks out with 120 psi compressed air-not responding. I've read some people remove the bleeder, install a NPT zerk and pump grease into the cylinders but this sounds messy as hell and a waste of grease. Going after the pucks with a XL Channelock pliers sounds like a recipe for disaster as well. Anyone have any tricks up their sleeve? (no, I don't have a DOT-3 pressure pot)

 

[1MeanA]

I spent a lot of time rebuilding mine including removing some stuck pistons. Fortunately you can buy new ones if they are corroded/damaged. I did use air and the grease gun. Of course you have to to put blocks between the pistons so you don't blow out the ones that aren't stuck while you are working to free the stuck piston. I used small pieces of plywood. I have to take water pump pliers to a couple of them to get them to move.

 

[Inertia]

If the pistons are screwed, and you intend to buy new ones, - I have drilled and tapped a hole in the bottom of the piston, then run a bolt down against the back of the caliper, then continue turning till it "pulls" the piston out .
Not done it to Kelsey/Hayes, but other seized calipers .

 

[4spdragtop]

"A waste of grease"?? How much we talking here....50 cents? How much is your time worth?
I tried air...NFG. Grease gun next and worked perfect.

 

[Dana67Dart]

recently say a guy hook the caliper up to a master cyl and use the hydraulic pressure to push them out. he put a stop between so they would not pop out (you just need get them to move) I would be sure to make a containment field around the caliper so the brake fluid can't spray all over the garage

 

[Kendog 170]

I almost gave up on a caliper until I popped it using a grease gun. Hooked to a MC would probably work best if you can put them back on and used a block of wood as suggested.

 

[hemi71x]

Lots of you know me for the rebuilding that i do with these 1965-72 A body, Kelsey Hayes disc brake calipers.

I have the Chrysler official special tool (Miller Special Tool) that was used in removing the pistons out of the caliper body.

But if you have stuck pistons the pumping them out hydraulically with grease works really well.
You will find that one piston wants to come out faster than the other one.
To limit the travel of that one just block it off, until they both come out of their bores evenly.
Good luck. You will get them out.
Jim V.
hemi71x

 

[Captainkirk]

Lots of you know me for the rebuilding that i do with these 1965-72 A body, Kelsey Hayes disc brake calipers.

I have the Chrysler official special tool (Miller Special Tool) that was used in removing the pistons out of the caliper body.

But if you have stuck pistons the pumping them out hydraulically with grease works really well.
You will find that one piston wants to come out faster than the other one.
To limit the travel of that one just block it off, until they both come out of their bores evenly.
Good luck. You will get them out.
Jim V.
hemi71x

View attachment 1716458473

@hemi71x Thanks for sharing the breakdown of that tool! I saw it in my Chrysler shop manual but picture showed it fully assembled. Could possibly fab something up like that if needed. As for the grease; sounds like the easiest path so I'll try that first.

 

[hemi71x]

I seriously doubt that you would ever be able to find any type of machine shop to fabricate parts that are used in that Miller Special tool.
The cost of doing something like that will be thru the roof.
If worse comes to worse, i can rebuild your calipers, for my labor time, and whatever parts cost wise would be need in getting them back into usable condition. Piston(s) and kits cost.
Or, you could even purchase the ones that i currently have listed for sale here on this forum.
I presently have two pairs of them in stock, waiting for them to find buyers.
After these two sell, that's it, I'm done with them, no more.

 

[1MeanA]

I think this is the video I watched a few years ago before tackling my calipers that had been sitting for a few decades. There is a serious safety hazard using compressed air as it will shoot those pistons out. Caution must be taken in blocking and releasing the pressure before removing the blocks.

 

[RustyRatRod]

Trying to clean up and re-seal my KH disc brake calipers and finding all four pucks on each caliper are stuck. I tried the usual trick of trying to blow the pucks out with 120 psi compressed air-not responding. I've read some people remove the bleeder, install a NPT zerk and pump grease into the cylinders but this sounds messy as hell and a waste of grease. Going after the pucks with a XL Channelock pliers sounds like a recipe for disaster as well. Anyone have any tricks up their sleeve? (no, I don't have a DOT-3 pressure pot)

Let me know if you need some pistons. I have some extras. I'll be glad to send you some for whatever shipping costs.

 

[Captainkirk]

Let me know if you need some pistons. I have some extras. I'll be glad to send you some for whatever shipping costs.

Thanks @RustyRatRod . I did manage to get all four from one caliper extracted and all have flaking on the plating but one is worse than the others. I'll let you know once I get the other caliper apart.

 

[Captainkirk]

"A waste of grease"?? How much we talking here....50 cents? How much is your time worth?
I tried air...NFG. Grease gun next and worked perfect.

No, not .50 cents. A tube of Brand X all purpose cost $8.99 and it's almost empty after doing one caliper. Those K/H calipers hold a pretty hefty amount of grease. I can see now that bleeding them is gonna be fun. Not.
Made a hell of a mess too, but I guess better grease than DOT-3 all over everything. That stuff peels paint. Literally.

 

[4spdragtop]

The psi difference between your typical compressor and a grease gun is a lot. I didn't know that either, I tried the air like you with no luck. Even if the grease is $20, it's still worth it imo. Yep messy, but a lot worse jobs out there.
Glad ya got them.

No, not .50 cents. A tube of Brand X all purpose cost $8.99 and it's almost empty after doing one caliper. Those K/H calipers hold a pretty hefty amount of grease. I can see now that bleeding them is gonna be fun. Not.
Made a hell of a mess too, but I guess better grease than DOT-3 all over everything. That stuff peels paint. Literally.

 

[Kendog 170]

My work if scrapping about 20 8packs of grease.

 

[Dave999]

don't have to be full of grease
fill em with (filtered) waste oil first then pump the grease in

if you just use grease and you drill out a zerk or bleeder precisely you can also get at it with a flat end roll pin punch down the hole (and a hammer), to hydraulic shock it, like you might with a blind hole bearing race in an aluminium casing, or a spigot bush in a crank.

suggest you wear eye protection... a tiny gob of grease will end up lubricating your eyeball and it hurts....

Dave

 

[RedFish]

I think this is the video I watched a few years ago before tackling my calipers that had been sitting for a few decades. There is a serious safety hazard using compressed air as it will shoot those pistons out. Caution must be taken in blocking and releasing the pressure before removing the blocks.

Image is closest I found of what textile mill used. The top was flat and had a crowd of a bolt pattern. The bolt holes were keyhole so only loosen with hex key. Safety was merely a little bar with spring pushing against one bolt head. Years after I left the mill, top came off one of those antiques. It took the top of man's head off and lodged itself deep into a block wall. The hours without an accident clock was reset that day. Nobody knows how much air pressure the man put in it. Just a couple lbs psi against 10 inches diameter suddenly escaping goes BOOM. Be carefull

 

[S'cuder]

Image is closest I found of what textile mill used. The top was flat and had a crowd of a bolt pattern. The bolt holes were keyhole so only loosen with hex key. Safety was merely a little bar with spring pushing against one bolt head. Years after I left the mill, top came off one of those antiques. It took the top of man's head off and lodged itself deep into a block wall. The hours without an accident clock was reset that day. Nobody knows how much air pressure the man put in it. Just a couple lbs psi against 10 inches diameter suddenly escaping goes BOOM. Be carefull

View attachment 1716459230

The typical ratio for an air powered grease pump that drops into a keg, drum or pail is 50:1. So yes, much more effective than a straight air hose. Caution is warranted indeed. Even muscle powered guns can generate some serious pressure.

Grease pumps look like the one pictured, which is in a rustproofing drum. Rustproofing/undercoat pumps are typically less powerful than grease pums, but still have a much higher ratio than a gear oil pump.

 

[Swinger 340]

Let me know if you need some pistons. I have some extras. I'll be glad to send you some for whatever shipping costs.

Wish I knew you had extra pistons when I installed K/H brakes on my 69' Dart two years ago. I did get the pistons out of mine, with a little effort but two were shot. I ended up buying two sets from Rock Auto for $100.00 a set. Done deal. Now I have some spare parts myself. BTW, much better braking power.

 

[RustyRatRod]

Wish I knew you had extra pistons when I installed K/H brakes on my 69' Dart two years ago. I did get the pistons out of mine, with a little effort but two were shot. I ended up buying two sets from Rock Auto for $100.00 a set. Done deal. Now I have some spare parts myself. BTW, much better braking power.

Lordy.

 

[1MeanA]

Rockauto doesn't have them right now. I should have bought some extras.

 

[S'cuder]

The pistons have kinda dried up. They pop up on Ebay sometimes. Hilltop Auto Parts has NOS, but as you'd expect, they're expensive. They might show up again because they are the same as used on some Mustangs, Fairlanes and Falcons.

Not too long ago it was cheaper to buy a reman caliper with new pistons than to buy four pistons. So I bought a couple for the shelf.

Here's a cross reference to help with a search.

 

[Captainkirk]

Let me know if you need some pistons. I have some extras. I'll be glad to send you some for whatever shipping costs.

Looks like I will be needing some. Anything you could scratch up would be a huge help! Thanks in advance

 

[hemi71x]

https://www.npdlink.com/product/pis...rms=caliper%2Bpistons&top_parent=200001&year=

IN STOCK.

 

[RustyRatRod]

Looks like I will be needing some. Anything you could scratch up would be a huge help! Thanks in advance

Ok. How many do you need? This is what I have. They're in very good condition.

They were given to me, so if you'll just pay shipping, that's all I ask. PM me so we can get together on it.