help with brakes

[Turton]

Hello everyone, my 66' 2A was braking fine before I messed with it! The problem I had was a spongy clutch, I looked into the reservoir and the fluid was really dirty. So I pulled out my brake fluid extractor that hooks up to my compressor. bleed all the lines, including clutch, the bottle on top of the reservoir never ran dry. now when I press the brakes it goes right to the floor, but I can pump up the pressure, then press the clutch and brake are gone again. what did I do?
thanks
Geoff

[red90]

The dirty fluid makes me thing the master seal has gone bad.

[The_Anachronist]

Agreed. Exact same thing happened on my old TR6 - worked great until I messed with it. Master went, followed shortly after by slave.

[Turton]

Ah the joys of owning a 50 year old vehicle! Thanks for the input
Geoff

[red90]

You have to be careful with the old seals as well. They are not compatible with modern fluids.

[Turton]

So I used Dot 3 brake fluid, was that correct?

[red90]

My understanding is that you are supposed to use Castrol LMA only.

[Turton]

nutz! Guess I'll be bleeding the system again, can I pick that up at any Lordco?
Geoff

[TOLON]

Geoff, I don't think you need to re-bleed the brakes if you used Dot 3 fluid. I think all brake fluid these days is low moisture absorption and Castrol is no longer castor oil but I found Castrol LMA at home hardware if you want to re-bleed and go the safe route.

Terry

[Turton]

Thanks Terry, I am replacing the brake master so I'm going to have to re-bleed anyways but I have a 4L jug of Dot 3 so it would be nice not buy something else
Geoff

[Rob]

Castrol LMA has been rebranded in many places as Castrol DOT 4. I have some older bottles of Castrol LMA which is a synthetic DOT4. There's lots of discussion out there on DOT 3/4/5/5.1 (don't use 5.1, it is silicone based) and the old green bible will make reference to Girling Crimson (which wouldn't rot the natural rubber seals). Castrol GT (later LMA) was the replacement but frankly I've used DOT 3 in my series trucks for about 25 years without much trouble. I was using DOT 4 in my Series 2 for the past couple of years without problems.