Clutch Master cylinder, rebuild or not.

[Norton47]

I know this will have lots of opinions and will depend on the quality of the bore.
This new Girling unit was installed 11 months ago, and has had the fluid flushed at 9 months.

It is now starting to drip on to my foot. This is a new Girling unit.
If inspection of the bore shows it is free of pits and or scratches gouges, dirt, etc,
Now the 100 dollar question, is there a good chance of rebuilding lasting at least as long at this new unit did?
Peoples experience's with rebuilding?

Also has anyone had better Mean Time Between Failures (MTBF) using another brand, perhaps heaven forbid an after market unit?

 

[TR3driver]

Should last a whole lot longer than that, even with a rebuild. Did you use Girling or DOT 5 fluid both to operate and flush it ?

I've pretty much always rebuilt my old cylinders even when I probably shouldn't. Even with significant pitting in the bore, the seals have lasted longer than 11 months of daily driving.

 

[TR4]

I rebuilt mine 2 years ago and it's still great, no leaks and operates as it should. I did think I had a leak but the cap was loose and was simply splashing fluid out on the twists and turns.

 

[Geo Hahn]

Ditto the rebuild suggestion. It takes so little time (something I have plenty of) and saves $$$ (never seem to have enough) that I always try rebuilding.

 

[Andrew Mace]

Also ditto. I've had rebuilt cylinders last well over 20 years....

 

[Norton47]

I am sure I used Castrol LMA for this and the brakes.

 

[DNK]

I am about to rebuild my clutch master in my 7.5. Should I use silicon to clean it if I am going to use it in my system? It has original now.

 

[TR3driver]

I am about to rebuild my clutch master in my 7.5. Should I use silicon to clean it if I am going to use it in my system?

IMO, yes. I usually start with solvent (on the metal parts), then finish with silicone.

PS I've never seen any indication that "brake solvent" harms modern seals, but I keep it away from any seal I'm going to use, just to be safe. However I was disassembling an original MC the other day (very likely with original seals in it) and the seals were grotesquely swollen by the time I got it apart. Could have been the heat, but I'm guessing they were the old "natural rubber" seals and the solvent is what caused them to swell like that. Still haven't gotten all the black goo off my hands !

 

[DNK]

Thanks Randall. Should I buy a hone for the inside of the clutch master?

 

[TR3driver]

Tough call, IMO. If the bore is in good shape, I'd leave it alone. If it's pitted, then it's probably better to replace it.

That said, I ran a hone through one of the MCs I just put together for the 56 TR3, as it had some very light pitting. Replacement MCs for the 56 are visibly different than the originals, so I want to try to keep them if I can. The other one looked good enough without the hone, so I didn't touch it. The hone leaves a rougher finish, which will probably accelerate seal wear at least until the bore wears smooth again.

 

[DNK]

Clutch masters by Girling are NLS. So I'd figure I would just rebuild it.

 

[TR3driver]

Clutch masters by Girling are NLS.

So this isn't your TR6 you're working on ? TRF even has Girling TR6 clutch MCs on sale at the moment. GI64068827 is the .75" bore and GI64066117 the .70".

 

[DNK]

No it's my TR 7.5

 

[TR3driver]

Ok, I'll bite : What's a TR 7.5 ?

If it's a wedge with a Rover motor, then GI64066614 looks to be the Girling clutch MC. Not on sale but listed as available ...

 

[DNK]

TRF?

 

[DNK]

saw it on their site. Took some hunting. Already bought the rebuild kit. Will attempt that first.

 

[TR3driver]

The Roadster Factory
https://www.the-roadster-factory.com/

 

[Guest]

I rebuilt my Spitfire brake master cylinder 3 months ago and it has been great. My clutch and brakes are all silicone DOT4 fluid now. The best part of that is we over filled the clutch master when we replaced the slave and when I got home there was fluid on the firewall shelf, I just wiped it off and the paint was still there.

 

[Moseso]

I see mention of "brake solvent" here.
Through many years of rebuilding British and non-British hydraulic parts, I have always used plain old denatured alcohol (from the hardware/paint store) to clean pistons and cylinder bores. It dries residue free and doesn't harm the rubber.

 

[DNK]

Thanks for the remembrance on that fact Moseso.