suggestions for rusted closed wheel cylinder

[Joe Meneghin]

The cups on the wheel cylinder from my 60 convertible are locked into place.  I have the first one on its side with the retainer cup soaking in Pb blaster.  Any suggestions?  I tried grabbing on to one of those ribbed caps with needle nose pliers but it wouldnt budge.

[Bruce Reynolds # 18992]

Gday Joe,

I had a similar problem with a couple of the wheel cylinders when I purchased my 60 CDV, and the only way I found to remove the pistons was to be brutal.

What I did was to get a socket that fits nicely into the wheel cylinder, put an extension into the socket, spray a liberal amount of CRC into the guts, and then gradually apply force to the extension in the way of repeated tapping with a hammer.   This tapping will usually need to be increased in intensity until it requires either more muscle power, or a larger hammer.

A couple of hints.  
(1)   Place a piece of rag around the area to stop and splashing back towards you, and tap harder if necessary.
(2)   Put the W/C flat on the solid bench till things start to move.
(3)   Tap from one side till that piston moves, then tap from the other side till that one moves.
(4)   Once one has started to move, clean out the rust from the outer part of the bore, and reinstall in position and bleed as normal, but without any brake linings in place, and then have someone applying the brake pedal to hydraulically force the loose piston all the way out.   Wrap the rag around the area to catch the piston, rubber and flying fluid when it pops out.

If things dont go to that plan, then you will have to just thump the livin bjesus out of the socket and drive the guts out one way.   At least you will pprobably be able to save the pistons, and possibly the spring, but the cups, naturally will be toast.  

The use of the extension is to keep the fingers from getting squashed, mashed or damaged in any way.

Bruce,
The Tassie Devil(le),
60 CDV

[Joe Meneghin]

Anytime I buy a rebuild kit for brakes (master cylinder, or wheel cylinder) I always wind up having this problem because of rust.

Between the two cars here, I have eight cylinders, so if  I can salvage four of them I should be alright.  I cut the rubber brake hose down to the end and was going to spray penetrating oil into the hose, and the brake fluid inside had turned into a solid.  Thanks for the advice Bruce,  Let me go get my sledgehammer.

[Doug Houston]

I wonder if NAPA might have new master and wheel cylinders for those cars. Its amazing what they can come up with.

Now, if the cylinder has that much rust in it, it would surely be beyond rebuilding. Soooo, the best thing to do is to send it to White Post Restorations in White Post, Virginia. They bore out the cylinder and press/seal in a brass liner so that you can put in a new kit, and have reliable brakes. The other half of the trick is to use silicone fluid in the system.

[Bruce Reynolds # 18992]

But, Joe, if yours are that bad, too much hammering might even destroy the pistons.

Joe and Doug,

Another route we go here is to have a machine shop bore out the cylinders and insert stainless steel tubes and then hone to size.

Works a treat, and will last forever.

Bruce,
The Tassie Devil(le),
60 CDV

[Jeff Maltby #4196]

Joe. Get a small cup/can and submerge the cylinder (remove the bleeder screw) in diesel fuel with some auto tranny fluid mixed in and let it soak overnite. Use a socket that fits the bore snug and tap it out on a vise, with the jaws spread just enough to let the piston drop out.

Then send all 4 cylinders to Brake & Equipment Warehouse in Minneapolis Minn and have resleeved in stainless for $36 each with club discount (M.C is $54) and save big bucks compared to anyone else offering this service.

http://www.brakepalce.com TARGET=_blank>http://www.brakepalce.com     612 378-3145

Jeff 49 coupe

[Jeff Maltby #4194]

http://www.brakeplace.com TARGET=_blank>http://www.brakeplace.com

[Joe Meneghin]

Diesel fuel and tranny fluid huh?  Thats a hell of a combination.  I tested the cylinder last week in a container of straight muratic acid and saw the cups began to foam very agressively.  I stopped it after a few seconds when I saw that, realizing the acid would have eaten thru the cups in about 10 minutes.  So I sandblasted the cylinder body to get it clean.  Last night after some thinking I thought of putting it a container of acid with about 1/8 of an inch of acid in it, just enough to reach the cup.  Ill try your suggestion first,  using my method I would have been sacrificing at least 1 cup per cylinder.  As I said earlier I have 8 wheel cylinders, hopefully I can get 4 rebuilt out of the 8.


With my luck it will be like the wheel cylinders on the old Datsun Z cars.  Your chances of winning the lottery would be better than getting out the bleeder screw without snaping it off flush with the body of the cylinder.  


Just out of curiosity, I cant do it because the car is completely taken apart but wouldnt hooking up new hoses and lines with brake fluid and bleeding it out unstick the piston?  
I thought the pressure from hydraulic fluid was incredibly strong.

[George]

Joe if the pressure from the brake fluid could possibly still move the piston out. It would be simpler to remove the cylinder and blow the pistons out with compressed air from the local service station. That would be a lot easier than going to the trouble of getting the brakes to work again, remember you would have to bleed the lines also. If the cylinders are so badly seized, loosening all of the bleed screws would be a murderous task..

[Joe Meneghin]

Thats a great idea George.  You think If I closed the valve on my compressor and let it open at 120 psi that would do the trick?

[Jeff Maltby #4194]

I just went through the bleeder screw removal problem on my 49. I even rounded the nut off with the proper flare wrench. I finally used a propane torch and applied some heat to the screw and it came out. Air might work on your pistons once they have been soaked ? All you can do it try whatever works.

I recently found a 55 dodge royal lancer that had been sitting in a barn since 73. The engine was frozen tight. We mixed diesel fuel with tranny fluid-filled the cylinders and let it sit overnight. The next day it started turning then even fired up but what a smoke screen.

[Brian Rachlin]

NAPA and other sources like Kanter Auto have new cylinder for most cars, even back into the 1930s.

For about $30.00 a piece, it seems like a lot less trouble that rebuilding old rusty ones.

If the lines look rusty, I would do them too.  I had total brake failure in an antique car once, and I always check the brakes carefully when I get a new (old) car.

Good Luck,

Brian

[JIM CLC # 15000]

03-21-05
Joe, bleeding will not do any good as you can bleed any brake system with a frozen wheel cylinder.
Been there, done that.
I was told by a very smart person that milk of magniesem(sic) would eat away rust.
You might try it.
Also, the pistons may not be all the way retracted into the cylinder, thereby giving you room to drive a piston in a fraction of an inch.
Be sure that the cylinder is the same size on both ends.
On my 38, the rear cylinders had two difference sizes of pistons,therefore I had to force the larger-one out by going thru the smaller end.
Hope this gives you something to work with.
If they are as badly rusted as you say, I would op for new ones.
Good Luck, Jim

[George]

Give it a shot, Wear safety gear.

[Joe Meneghin]

Been busy this week, but after 1 day in straight acetone.  The bleeder screw came out very easily.  Ill try the caps again tomorrow morning.

[JIM CLC # 15000]

03-24-05
Joe, whatever you do, DONT use compressed air to remove the brake cylinder pistons, (unless you will be at a fireing-range)
Since you were able to get the bleeder-screw out, try to screw-in a grease fitting and force the pistons out with a grease-gun.
Much safer that way,as the pistons will come out slowly, not like a cannon fireing.
Good Luck, Jim