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Disc brake puck removal

absunbeam

Platinum Level Sponsor
Is there a easy way of getting the puck removed from the caliper? They have been sitting awhile and don't budge.
 

Warren

Bronze Level Sponsor
Pumping grease is the easy way if you can find a fitting. A lead on the exact one would be helpful. Grabbing them with a wrapped pair of Channel locks most always makes the next call to Sunbeam Specialties for those expensive stainless steel pistons.

PS yes I get it the size of your grease gun may vary :)
 

65beam

Donation Time
Air pressure works also.
I've used air before but I don't separate the halves of the caliper . You need to restrict the piston from hitting something else. I have a cone shaped rubber chuck for the air hose for things like this. The chuck is cheap at Harbor Freight.
 

absunbeam

Platinum Level Sponsor
Thanks for the suggestions, tried air pressure first no luck. Will look for fittings to hookup a grease gun. Since they have been sitting for 30 years the rubber is probably stuck to the inside of the cylinder, just hope they are not pitted.
 

Barry

Diamond Level Sponsor
A typical home / shop air compressor provides about 125 PSI. A typical hand operated grease gun can generate several thousand PSI. Advantage, grease gun.
 

mikephillips

Donation Time
I have to admit I always separate the halves and I've never had an issue with doing that. To get the pistons out I use a piece of wood against the mating surfaces and then clamp them in a vise against the outer surface and the wood. The first try grabbing the piston with vise grips and pull, while hitting the grips to cause the piston to turn while pulling. You may also want to use a torch to apply heat to the piston to help break the rust that can develop between the outside and the sealing ring. I find that both helps break the seal. If that doesn't work, and pumping air or grease doesn't if used, then you'll have to get more aggressive. I took apart a pair that were on a car left in a field for what they told me was close to 20 years that a brake shop couldn't remove. What I did was split them, then take the halve and heat them until the remaining fluid was steaming out of the connections, then took the halves and tossed them into a bucket of cold water. One half needed this twice, the other 3 just once and the thermal shock broke the pistons loose so I could twist them out. But, if you go this route you're committed since the water will get sucked into the piston chamber as it so quickly cools and you don't want to leave it in there.

Being apart also allows you to more easily clean the rust out of the pressure seal groove in the bore and the one for the dust seal, as well as clean the surface between the pressure seal and the outside. I've use a rotary tool and stone for the pressure seal groove and a small cutoff wheel to clean the dust seal groove. It's easy that way to get all the dirt and rust out without really risking damaging the castings since it is easy to feel the difference between the junk and the cast iron.
 

PROCRAFT

Donation Time
I've used air before but I don't separate the halves of the caliper . You need to restrict the piston from hitting something else. I have a cone shaped rubber chuck for the air hose for things like this. The chuck is cheap at Harbor Freight.
How about a piece of wood ? Just like we used on the Brembo stuff and there is a tool around that that expands to the inside of the piston to yank it out so to speak.
 

jumpinjan

Bronze Level Sponsor
I got every piston out in all the calipers I have rebuilt using compressed air. And I probably used heat like Mike Phillips suggested
Jan
 

puff4

Platinum Level Sponsor
I got every piston out in all the calipers I have rebuilt using compressed air. And I probably used heat like Mike Phillips suggested
Jan
Ditto. Air seems to have worked for me. I've not ever gone the grease route for calipers or crank pilot bearings, simply because I didn't want to deal with the mess. For pilot bearings I use a tappet puller... works great.
 

jumpinjan

Bronze Level Sponsor
On the contrary, I have removed pilot bushings using grease & an old input shaft way back years and years ago. But yes, now I also have & use an I.D. bushing puller.
On one occasion the bushing was so worn, I wrapped the input shaft with masking tape to get a tight fit in the bushing. And hit the shaft with a hammer and it came right out.
Jan
 

PROCRAFT

Donation Time
On the contrary, I have removed pilot bushings using grease & an old input shaft way back years and years ago. But yes, now I also have & use an I.D. bushing puller.
On one occasion the bushing was so worn, I wrapped the input shaft with masking tape to get a tight fit in the bushing. And hit the shaft with a hammer and it came right out.
Jan
I just use grease and hydraulic it. Not that big of a deal.
 

Limey

Donation Time
I was not convinced with the effectivity of air or it's safety so I used grease this week on a very manky pair of calipers. Works a treat. Nice and controlled. Bloody messy tho....You have to remove all the grease in a petrol bath before ultrasonic cleaning. Then I glass blast the bodies, ultrasonically clean and lastly paint with a high heat paint which is oven baked at 250deg for an hour which makes the paint chemically impervious and her indoors furious;) It's easier to apologize that get permission but the roast dinner did taste a bit funny:rolleyes:
 

junkman

Gold Level Sponsor
The easy way in my neighborhood is to drill a hole in the piston and tap with a 3/8s tap then screw in a bolt and out she comes. By the way I have never taken apart a caliper that had useable pistons, always need new ones.
 

bernd_st

Bronze Level Sponsor
That's an interesting method I never heard of. Sounds dead easy. Normally I always remove them with compressed air. A piece of thin hardwood in between and a loud plop makes them come out w/o damage - in 90% of all cases. Heard about the grease method but never tried it. I'm always installing stainless piston sets nowadays -truly a fit and forget solution..
 
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absunbeam

Platinum Level Sponsor
The easy way in my neighborhood is to drill a hole in the piston and tap with a 3/8s tap then screw in a bolt and out she comes. By the way I have never taken apart a caliper that had useable pistons, always need new ones.
That worked great! Grease method got one out, seeing the condition of the piston (Rusty), split the caliper drilled & tapped a 3/8-16 bolt and jacked the piston out. Easy way to clean the grooves with a wire brush, lots of debris. Does anyone know why in the manual it is listed as a temporary fix when you split the caliper? They suggest they get sent back to the factory.....good luck with that. Thanks to all who responded
 

DanR

Diamond Level Sponsor
Does anyone know why in the manual it is listed as a temporary fix when you split the caliper? They suggest they get sent back to the factory.....

Al, It is in my opinion that proper torque is most critical when reassembling.

The small rubber "o" ring that has flat sides can be obtained from our SS & CS suppliers.

NOTE: There are 2 different specs for torque of the caliper body bolts so BEWARE, use the late series torque specs.
If you can't find them let me know and I will go hunt them up..... gott'em some where:)

Another suggestion is to take a small drill bit (carefully) clean the fluid passages in the caliper halves. They most always have crud that restricts.

I found some "new bolts" for my re-build to replace the old ones that showed too much deterioration on the heads.
 

Limey

Donation Time
Al, It is in my opinion that proper torque is most critical when reassembling.

The small rubber "o" ring that has flat sides can be obtained from our SS & CS suppliers.

NOTE: There are 2 different specs for torque of the caliper body bolts so BEWARE, use the late series torque specs.
If you can't find them let me know and I will go hunt them up..... gott'em some where:)

Another suggestion is to take a small drill bit (carefully) clean the fluid passages in the caliper halves. They most always have crud that restricts.

I found some "new bolts" for my re-build to replace the old ones that showed too much deterioration on the heads.

I can't swear to the accuracy but on an E-type forum that uses Girling Type 16 group they recommended 70 and 45lbft
 
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