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Any tips on how to remove frozen pistons from drum brake Wheel Cylinders???

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christophe

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I rebuilt one set of wheel cylinders on my 100-4 only to have more of them fail later on. All cylinders are either leaking or freezing up. I have drained all fluid from the lines, but the right rear is still locked up. I can't even turn the drum by hand. When i was rebuilding the front drum cylinders, one of the pistons refused to budge out of the wheel cylinder. I tried to pry it, but ended up breaking the wheel cylinder housing. I tried compressed air, but that did not work either.

So, any tips on getting the pistons out of the wheel cylinders?
 
Yes, but I need 8 wheel cylinders. I rebuilt 3 of the fronts in just 30 minutes, but did break one. The rears may just have to be replaced. I was trying to avoid spending 400 on wheel cylinders since there appears to nothing wrong with the bores and only the seals.
 
I use hydraulic pressure to displace the pistons. Even a grease gun will generate pressure, if you don't have access to proper pumps.
 
Six per vehicle, not eight. The front brakes indeed use two cylinders per wheel but the rears use only one per wheel.
 
Christophe

Are you saying that a rear brake drum will not come off? 'I can't even turn the drum by hand'

Have you tried releasing the adjuster? You may need to use penetrating oil on it if that is also frozen

Slack it right off then tap the drum all round with a hide mallet to try to release it.

:cheers:

Bob
 
I pushed my front caliper pistons out with 150# of air pressure. I wasn't thinking clearly but I was lucky. The air wouldn't move them until it did! The piston landed 20 foot away in between the boat and truck. Not a scatch on either.
 
Bob Hughes said:
Christophe

Are you saying that a rear brake drum will not come off? 'I can't even turn the drum by hand'

Have you tried releasing the adjuster? You may need to use penetrating oil on it if that is also frozen

Slack it right off then tap the drum all round with a hide mallet to try to release it.

:cheers:

Bob
Click to expand...

I backed off on the adjuster as i did on the fronts and the drum released. It appears that this car has had been upgraded to the later hypoid rear end and brakes. My car is in the 15,000 range and moss motors states that they did not start using the hypoid unit until somewhere in the 20,000 range.

Anyway, i am not entirely sure why the rear passenger brakes were locked up. Both sides have very fresh looking pads and wheel cylinders. I do not see any leaks and that side was working fine until i messed with bleeding the brakes with a suction unit last week. I'm going to remove both wheel cylinders this evening and inspect them throughly. The brake fluid was extremely dirty and had a lot of garbage in it, so perhaps that contributed to the problems.
 
There's a guy IN Birmingham (Hoover maybe?) that's owned and worked on Healeys since the mid 70s; I could hook you up with his phone number if you want to PM me.
 
Well, the previous owner of my 75% complete ground up also rebuilt the cylinder seals......all failed and leaked.....sent all 6 to WHITE POST restorations and all came back looking perfect in hermetically sealed bag..popped them on and 7 years later still workin good.....minimum time, minimum money.

Pete
 
HEALEYJAG said:
Well, the previous owner of my 75% complete ground up also rebuilt the cylinder seals......all failed and leaked.....sent all 6 to WHITE POST restorations and all came back looking perfect in hermetically sealed bag..popped them on and 7 years later still workin good.....minimum time, minimum money.

Pete
Click to expand...

The bores all look fine, so i really dont want to spend the money to have whitepost do the same thing that I can do in ten minutes. I've used them before and as far as master cylinder rebuilds are concerned for C1 and C2 Corvettes, they are not cheap. None-the-less, thanks for the suggestion
 
Randy Forbes said:
There's a guy IN Birmingham (Hoover maybe?) that's owned and worked on Healeys since the mid 70s; I could hook you up with his phone number if you want to PM me.
Click to expand...

That would be great, Randy! I'm going to need somebody to help me tune the 1960 3000 when it is finished and if I end up needing help with the 100, the number might come in handy sooner.
 
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