Girling master cylinder rebuild?

[fulltilt]

I recently pulled my master cylinders out of the car. I removed the boot/dust cover, removed the retaining ring and push rod. Now I am looking at a concave part that is retained by the housing itself. I can't see any internal ring that I can remove that will let me disassemble it any farther. Can anyone help me?

Kyle Verploegen

[Brian]

that's the piston. bang the cylinder down gently on the bench to knock it loose. Or blow a little compressed air into the out-port. A little air being the key, unless you want to chase the piston all over your shop.

Brian

[kea]

I sell Girling master cylinders, because the rebuild success rate is low.
If the piston is difficult to remove (you found the need to post on the internet) by taping on your work bench, I then wonder, whats keeping it stuck inside.
If the cylinder bore is pitted or scored, it's done. They don't make over-sized seals that allow you to hone out the bore for repairs.
Keith
Averill Racing Stuff,Inc.

[JHaydon]

I've found on my own masters that the piston can get cocked in the circlip groove, or else (like a piston pin retainer) the outer part of the bore beyond the groove has developed a bit of a lip from being banged into for years.

I've always had success with compressed air, but as Brian mentioned, a little goes a long way -- literally!! Just the leakage from an air gun (don't even open the valve) will be enough to eject it.

If the bore is pitted, then it will need replacement, not rebuilding, as Keith suggests. But I'd think you'd be aware already if the bore were so pitted that you couldn't move the piston.

(BTW, we sell many more times rebuild kits than new cylinders ) If you rebuild them frequently enough and keep your fluid fresh, you shouldn't have a problem with pitting.

[kea]

J Haydon, Of course you are going to sell more rebuild kits than master cylinders, as racers are always looking to control their costs. But, what is the rebuild success rate and did those masters need a rebuild to begin with (was anything really worn out)?
I don't sell Girling rebuild kits for those reasons.
Keith

[JHaydon]

Customers rarely tell us the condition of their masters when they order rebuild kits, but the only customers I'm aware of who have had troubles rebuilding masters are people who have waited too long to rebuild and have ended up with pitted cylinders. I do know that we have many customers who successfully rebuild their masters as a matter of preventative maintenance (including me).

You are absolutely right that a pitted master cylinder is not salvageable, but if the cylinder bore is still smooth, a rebuild is still appropriate.

The fellow who sold me my old FV used to rebuild the masters and the wheel cylinders every season (and he kept the old seals as spares). He'd replace the cylinders if there was any sign of pitting, but with his maintenance schedule, that was very infrequent.

[Brian]

I figure that if a MC has failed, then it's toast, I don't even try to rebuild it (" How dare you fail! Begone, curs'd instrument of my potential destruction, into the floatie pond with you!" )

I replace my MC's every five years or so, zero maintenance except for bleeding and changing fluid, etc, in between. If I rebuild a cylinder then it goes into the clutch box, not the brake box.

But that's just me, what do I know?

Brian

[rickjohnson356]

I wish I could hold on to a car for five years!!!

Maybe this time will be the charm?

[Brian]

I only did it once, on a customer car. But I was gonna change my MC's on the ones I sold!

Brian

[fulltilt]

[size=2]Knowing it should just come out, I pushed in and let it return real fast a couple times against whatever it was blocking it and it came out without air. Thanks![/size]

[Larry]

I'm with Keith on this one! Rebuilding master cylinders has proven to have mixed success. While new master cylinders aren't exactly cheap, they last a long time and the slight additional expense is worth it due to peace of mind and lack of hassle.

Like Keith, I no longer carry master cylinder rebuild kits for this reason.

Larry Oliver
International Racing Products

[Jon Jeffords]

Brian, I just read your quote:

"Begone, curs'd instrument of my potential destruction."

I was able to clean up my monitor without much trouble, but I'm not sure how I'm going to get a mouthful of coffee out of the keyboard. Ain't that the truth!

[Brian]

I've been waiting for someone to ask about the "floatie pond" but no one has

Brian

[RoadHazard]

I've been waiting for someone to ask about the "floatie pond" but no one has

That's where you toss the hardware into the pond to see if it floats, right? If it sinks, it was good. If it floats, it's no good and needs to be replaced anyway. Kinda like testing witches, IIRC.

[BGilkes]

See a separate thread that I started about 9 months ago after a failure at Road Atlanta coming into Turn 10..... even though I didn't hit anything the damage done to the car going through the gravel trap and the instant greying of my hair, and I am only 23 makes the cost of a new master cylinder seem ridiculously cheap.

Agree with Brian's view, save a rebuilt one for the clutch (I have had one of those fail too & I only use it to get out of the pits).

Brent

[Brian]

is where Mr. Floatie lives: a unique Canadian politician, believe it or not...

http://www.poopvictoria.ca

Brian

[D.T. Benner]

So tourist are not the ONLY thing Vancouver sends to Victoria? EH.

[Frank C]

I have usually respected the opinions of Keith Averill and Larry Oliver, but I don't agree with them at all on master cylinder rebuilds. Perhaps I am old-fashioned, but I have always believed that replacing seals in master & slave cylinders and calipers was preventive maintenance. I would not dream of going 5 years without a hydraulic systems rebuild. I have never had a cylinder failure in my race car; just in British street cars that did not get such preventive maintenance. New seals always have worked in them, too. Obviously seals will not work if the bores are pitted, but I think regular maintenance helps to prevent this, too. I don't think those new to the sport should take so much stock in the opinions expressed above except for John Haydon's. His comments match my experience and I have been driving and maintaining British cars and their hydraulics since 1963! If anyone wants to toss their used master cylinders my way I will gladly accept them.
- Frank C

[Larry]

Frank, I don't mind you disagreeing with my opinion--my wife does it all the time. She has even been right on many occasions. I'm glad that you've had success in rebuilding master cylinders, but there are many who haven't shared your success--for whatever reasons. In the case of a master cylinder, my opinion is based on the facts that (1) they are relatively inexpensive to replace, and (2) many people have had problems rebuilding them.

Larry Oliver
International Racing Products