Castrol GT LMA Brake Fluid....

[SafeAirOne]

I've been letting my slow wheel cylinder leak go for a while now, knowing that at any time I can go down to my local parts store and pick up a pint/quart/gallon of Castrol LMA when I run out of the new land Rover DOT4 fluid our hosts sent me. (I know, I know...)

Well, I ran out of the Land Rover fluid today, so I headed down and...What's this??...Castrol "New Formula" synthetic GT-LMA!!!

Is this compatible with: 1) the old non-synthetic fluid and 2) the natural rubber seals in Land Rover brake systems (which, in all likleyhood, haven't been natural rubber for several decades now)?

[jac04]

Check this out:

http://www.roversnorth.com/forums/showthread.php?t=7900&highlight=gtlma

[SafeAirOne]

Check this out:
http://www.roversnorth.com/forums/sh...ighlight=gtlma

Enlightening (at least the part on the MGB board). Don't know how I missed that post. Thanks.

[brucejohn]

Okay, do I have this right?

DOT 3/4 contains no silicone, though it may be synthetic and DOT 5 contains silicone, so does not play nice with old Rover rubber parts.

So, it may be okay to use Castrol GTLMA DOT 4, though not as good a Land Rover DOT4 from our host.

[SafeAirOne]

Okay, do I have this right?

DOT 3/4 contains no silicone, though it may be synthetic and DOT 5 contains silicone, so does not play nice with old Rover rubber parts.

So, it may be okay to use Castrol GTLMA DOT 4, though not as good a Land Rover DOT4 from our host.

After reading the cited post, my take on it is: The synthetic Castrol GT-LMA is OK to use and

The brake fluid our hosts now sell is a private label version of a compatable brake fluid which has been blessed by Maurice Wilks' descendants (or their Tata equivalents),

and...

DOT 5 has always been silicone-based and is (in my opinion) dandy if you have a virgin braking system (you just overhauled everything), but shouldn't be mixed with the non-silicone fluid and the rubber parts that you've been using with the old non-silicone fluid.

[thixon]

DOT 5 has always been silicone-based and is (in my opinion) dandy if you have a virgin braking system (you just overhauled everything), but shouldn't be mixed with the non-silicone fluid and the rubber parts that you've been using with the old non-silicone fluid.

Nice recap!

A buddy of mine was so concerned about this that he called castrol customer support. The guy at the end of the line (possibly in India) told him it had always been "synthetic," and then rattled off some spiel about the higher boiling point. He of course couldn't answer any questions, and probably did'nt know grade 8 nuts from brazil nuts. Go figure.

There's stuff on brit car boards of every marque covering this topic. Assuming everyone's research is correct, it doesn't seem to be cause for alarm.