Hydraulic reservoir

[Lynn Eades]

Having had a quick read on the net, I think I would stick with dot 3 or dot 4. Silicone fluid (dot 5) is not recommended by Porsche for instance. Silicone has other problems. I think better the devil you know unless you were replacing all the components. Keep your fleet the same. My gut feeling.

[Bruce Parker (RIP)]

Originally Posted by Lynn Eades

Having had a quick read on the net, I think I would stick with dot 3 or dot 4. Silicone fluid (dot 5) is not recommended by Porsche for instance. Silicone has other problems. I think better the devil you know unless you were replacing all the components. Keep your fleet the same. My gut feeling.

Thanks Lynn, that's what I was tending towards. If I didgdo to Dot 5 I probably would have run new lines anyway so everything would be new, but the existing lines are great and would be a pain to re-run. The old fluid gave me 12 years and who knows how many more had I not gone all nervous (plus covid spare time). My only problem was fluid boiling in the accelerator slave which is located right below the manifold exhaust pipe. I have since installed a heat baffle that seems to have solved the problem.

[Barry Churcher]

I hate Dot-5 and dread working on the vehicles that the owner insists using it. The spongey pedals and soft brakes become my problem all of a sudden. We learned to say "no warranty on Dot-5 brake jobs" . Photos taken by CUCVRUS.
Cheers,
Barry

[John Mackie]

My comments to Lynn in post 12.
I grew up with the old brake fluid that was made from caster oil and metholated sprit, we used metho to wash up brake cylanders . then we got mew high temp fluids that had a higher boiling point but were water soluble, we used water to wash them up.
I restored a truck many years ago and used silicone fluid I think it was Ok.

Recently I bought a hydraulic stop light switch (13480) Marathon and in the packet it had a note NOT TO USE THE SWITCH WITH SILICON FLUID !!!

I an currently restoring a Ford truck (11T ) and will not be using silicon fluid in it.

[Harry Moon]

I used methyl hydrate to flush mine. I've been using silicone fluid for 40 years with never a problem but for the last few projects i use a pressure bleed system and fill the systems from the wheel cylinders or slaves. the pedals are hard right away and if replacing a brake sensor(too often grr) a quick push from the closest wheel cylinder clears any bubbles out of the system.the trick is not to create and bubble up the fluid.