Brake and clutch fluid 73 TR6

[Flummoxed]

Almost everywhere I've searched, I read that Dot 3 should not be used in my 73 TR6 brake system. However, Dot 3 is what the reservoir lid tells me to use. Also, would this also stand to reason that Dot 3 is used in the clutch, too? I did read one time that the use of Dot 4 or 5 only applies to the very early Triumphs. Can anyone help me with this. Thanks.

 

[healeyboz]

Is this a new system? If new, use DOT 5. If not, someone else will be on here to help.

 

[Flummoxed]

No, it's not new. Not knowing what fluid the previous owner put in, I'm going to bleed both brake and clutch systems. Just not sure which fluids to refill with. Thanks for the reply.

 

[scubabatdan]

I have a 73 Midget and it takes Dot 3, There was a discussion a couple days ago about avoiding using Dot 5 in a Dot 3 system due to the fact it will eat and destroy rubber seals exposed to Dot 3 fluid. If in doubt go with Dot 3. Save you some headaches down the road when you seals fail.
Ðan

Here is the thread: https://www.britishcarforum.com/bcforum/u..._Flu#Post423758

 

[sparkydave]

DOT 3 is OK, but don't mix DOT 5 and DOT 3; they won't mix.

 

[healeyboz]

DOT 3 ate and I mean ate up a brand new system that I built.

 

[sparkydave]

I think (Barry, feel free to correct me) what he means is that DOT 3 has a nasty habit of absorbing moisture from the air and causing lots of corrosion inside the brake system, eventually leaving lots of brown sludge. It seems to be much worse on LBCs because they aren't air tight, and even modern cars can absorb moisture eventually through the rubber hoses. If you use DOT 3, you'll need to change the fluid regularly. You might want to look at something like Castrol LMA (Moss Motors has it, I haven't seen it in stores), or Valvoline Synpower brake fluid, since both of those profess to be less prone to absorbing moisture. Those are OK to mix with DOT 3.

If you need to identify what you've already got, DOT 5 starts out purple, but may fade to something clear. If the fluid is amber or brown, it's DOT 3 or 4. If it's really dark brown, it's very old DOT 3 or 4.

 

[Flummoxed]

Thanks for the help, guys. Is dot 3 okay for the clutch system as well?

 

[healeyboz]

Dave,
You are correct. However, my system was a new rebuild and after sitting for a few months Dot 3 started to drip out of the brand new calipers. I will NEVER, use dot 3 in the Austin Healey again!

 

[Ed Kaler]

Guys there is one simple solution (no pun intended ) simply use Castrol GT/LMA which IS available practily EVERYWHERE. :thumbsup:

Ed