ATE brake fluid in an 1960 MB 190SL

[hholbein]

My friend has inherited an old 190SL that has sat in a garage undriven for 5 or so years.

She indicated it had some brake issues (perhaps a stuck rear drum shoe, so I took a look.

First thing I noticed was that the brake fluid reservoir was bone dry, with just some oily bluish/black residue in the bottom. The service manual from that era recommends only ATE and "Lockheed-equivalent" brake fluid.

A few questions for you:

1) Has anyone experienced this ATE residue situation? I do know it is blue vs. the normal clear/amber DOT-3 fluid from Prestone

2) Is DOT-3 fluid compatible with old ATE fluid? She did put some DOT-3 Prestone in the reservoir and seems to be

3) Oddly enough, the pedal is quite firm -- no sponginess that you'd see with air bubbles in the lines.

4) No obvious leaks in the lines or master cylinder when inspecting.

Thanks for your input!

 

[MolaKule]

From this site, it looks like a DOT 3 or 4 would work:

ATE

I would contact the ATE company via email or phone and get a clarification.

I would also have the system flushed for safety reasons.

 

[JHZR2]

When did DOT 4 come on the scene? What was used before DOT 3 and 4?

Id personally call the MB Classic center in Irvine, CA, and see their recommendation. You may or may not make the buy, they are pretty level headed there, not being a for profit dealership, so they may say to just go out and buy "x".

 

[y_p_w]

Originally Posted By: JHZR2
When did DOT 4 come on the scene? What was used before DOT 3 and 4?

Id personally call the MB Classic center in Irvine, CA, and see their recommendation. You may or may not make the buy, they are pretty level headed there, not being a for profit dealership, so they may say to just go out and buy "x".

DOT 2 was a blend of castor oil and alcohols that was compatible with natural rubber hoses. I think it's the addition of synthetic materials that made glycol fluids possible.

This article claims that modern brake fluids should be fine in almost any car as long as the natural rubber components are replaced. It makes claims that in a classic car, the natural rubber stuff would probably be too degraded and would need to be replaced. The only suitable replacements are probably made of modern materials.

http://www.mossmotors.com/SiteGraphics/Pages/Brake_Fluid/brake_fluid_long.html

 

[JHZR2]

Great link! Yeah so DOT2 was more like 1950s. SO a 1960 vehicle may well be iffy there.

But just as iffy is trusting the life of rubber parts new or old in a car of that age. If I were the owner, Id replace any rubber parts in the system first, then use modern fluid and call it a day.

 

[andyd]

The first thing to do would be to fill the system with DOT 3 . Scratch that, the first thing to do is free up the bleeders. A 54 yr old NJ car is bound to have rusty brake lines. Even a hand made German car. Someone pushed on the pedal and a line blew. They put the car into the garage and the fluid drained out it.

 

[hholbein]

Thanks, folks for the many good suggestions. I'll post back when I've checked a few of these alternative sources.