Hi Eric,

I suppose when you say you are boiling out the air bubbles your are really using a vacuum pump to evacuate the air? (You know that not everybody works in the air conditioning field and has access to a vacuum pump!).

I hate to admit how long I have had silicon brake fluid in my 66 Alpine. Its got to be over 20 years and still holding. I remember it was a good name brand of silicon fluid. I think it was a GE product? In any case fellow motorists, I am going thru the car now and will be rebuilding and changing the fluid. However it is still working. Duel cylinders does seem like a good idea.

I think and someone correct me if I am wrong that the boosted original cylinder was .75 (3/4") bore and the non boosted series I and II used a cylinder with a .625 (5/8") bore. I have driven my Alpine thousands of miles using the 5/8" bore cylinder and no booster and stainless covered flex hoses and have been really happy with the braking.

Dave Reina

quote ImpBarn:

Brake fluid type is a bit like discussion religion. Its still a hot debate over what to use. In my experience for cars like ours which do not see daily use, DOT5 silicone fluid has significant benefits. It is essential to clean out the system entirely, and then install the DOT5 fluid properly. The common complaint is the DOT5 made my brakes spongy. That’s usually because it was applied incorrectly with a vacuum pump. We all know that DOT3 fluid is hydroscopic (absorbs water, which causes rust and corrosion). Well DOT5 is hygroscopic, it will absorb air. It must always be pushed through the system with pressure from the reservoir and the bottle should be fresh and never shaken. The other nice thing is that DOT5 will not eat paint if spilled accidentally.

Here is another thread on the subject, with testimony from Tiger Tom:

I’ve taken additional steps to insure all the air is out of mine, and my Alpine has a solid pedal with DOT5.
Here’s a demonstration of all the air being boiled out of a sample of silicone brake fluid.