TR6 Correct clutch master cylinder fluid for 69TR6?

[ichthos]

Well, after two years, my clutch master cylinder failed. I just finished rebuilding it. The old fluid in the cylinder reservoir was a dark grey - obviously not a good sign. I thought I used the correct fluid, but it must have been wrong considering the result. I plan on removing the rest of the fluid and bleeding the whole system tomorrow. Can someone tell me the correct fluid to use? Are all fluids with the same DOT value the same? Are the symptoms I stated truly a result of using the wrong fluid? Suggestions would greatly be appreciated.
Kevin

 

[DougF]

What did you use the first time? Where are you buying the rebuild kit?
I have found that Dot 5 does not work with the rubber that VB sells. It works well with TRF products, but I can't comment on Moss.

 

[PeterK]

I still use Castrol GT LMA (Low Moisture Absorbtion). It's DOT 3/4 and has proven itself for decades of use (obviously not the same fluid in my car for decades!).

Be sure to flush out all the grey crap before the final bleed. If it's in your reservoir, it's also in your lines.

I would recommend also rebuilding the slave at the same time as the master.

 

[ichthos]

Thanks Peter. I will be ordering the rebuild kit for the slave cylinder shortly.

 

[Got_All_4]

Natural rubber seals require DOT 5. Any other fluid will destroy the seals.

I Bought VB seal kits for my 69 TR6. What fluid should I use? Not started the project yet.

 

[Got_All_4]

DougF

I read your post about not using dot 5 brake fluid with Victoria British brake seals. That's what I purchased for my TR6 brake and clutch systems. What should I use. Do they list this some where or how did you find this out?

Thanks
Larry