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Hanging on the dash of my 37 chevy p/u was a handwritten tag saying use silicone brake fluid only. I have looked for this by haven't found any. Is there such a fluid. Thanks sj

Have a look at this site. It explains a bit about silicone brake fluid.

http://www.canadiandriver.com/articles/jk/060531.htm

George

Thanks, i'll take a look

i just did and search or silicone brake fluid and it basicly said that its old tecnoagy its thicker and harder to bleed but i found that bel-ray sells silicone brake fluid

http://www.belray.com/consumer/prod...bae3-4075-87fd-40393e54f7f8&offset=5

Hi. It is also called DOT 5
I use it in several of my older trucks and cars that I don't use very often. I found it easy to work with as long as you take you time bleading, NO pumping up. I even have it in a 62 C50 with a hydrovac. Gravity blead when you can work best with DOT 5. The key is dont mix with DOT 3. Start out with completely new system.

Every parts store around here has the DOT 5 silicone brake fluid. As stated above, if you have DOT 5 fluid in your system, keep using DOT 5.

I gave DOT 5 a try in the '55, all new hydraulics-wheel ctls, master, and lines. Bleeding was no problem, and the brakes worked great. Then one day I noticed a small puddle under the truck. I cleaned it up cause I didn't really see anywhere that it could be from. Well, it came back. I kept an eye on it for a while to see what it could be. Turned ou to be the master cylinder, the front wheel cylinders were leaking slightly as well. I called the manufacturer and explained the situation. I was informed that DOT 5 is not compatible with most brake components. I had also seen an article by Bob Adler in Vintage Truck on the same subject, he had also suggested not using DOT 5, unless it was called for as OE. After flushing the system, I put DOT 3 in and have had no problems since. If you plan on driving the truck regularly, stick with DOT 3. That's what it calls for, you'll avoid many hassels using that.

This debate has been going on for years now.

Here's my 2 sense worth: It's the best thing going! It's easy to work with, won't remove the paint from your truck parts, will not allow moisture into the system and once it's in the system, it works as good as the other stuff. I rebuilt the brake system on my 37 in 1980 and had it in the brake system of my 37 pickup since then. I have never had a problem!! Never!!!

Joe

the only caveat is not to get around anything you are going to paint because it will cause fisheye in the paint even in the smallest amount. i use dot 5 in my mga and have for years because it sits 7 months out of the year. but it does cause a little spongy feel and it is said not to use in a corvette system. Ron

I have also read Bob Adler's two articles on DOT 5 Silicone brake fluid but my interpretation of his conclusions are a little different. After reading his articles, I concluded that his main concerns about silicone brake fuid (DOT-5) were:

(1) do not use it in a large truck that has a vacuum brake booster;
(2) make sure that all rubber parts are compatible with DOT-5 and that all rubber parts are new (never used with other types of brake fluid); and,
(3) make sure that you do not get the DOT-5 contaminated with oil (good advice for any brake fluid).

I am fairly certain that Bob once told me he was using DOT-5 in one or more of his trucks.

Here is a pertinent section from one of his two articles:

"Summary So Far

Choosing a brake fluid, machine shop, chrome-plating shop, physician or spouse is a really personal decision.

One of life's personal pleasures is looking inside a master-cylinder reservoir with clean, rust-free surfaces after ten years of silicone fluid use. Our main concern with brakes is that after a complete rebuild, they should work reliably for a decade or two before needing another rebuild. One way to extend this rebuild interval is to change glycol fluid every few years. If your maintenance schedule is likely to become lax, silicone fluid should not need changing as often.

If you use new name-brand components and fluids that meet specifications, silicone fluid is a good bet.

Beware of silicone leaking through a vacuum booster and scouring the engine. Performance DOT 4 fluid may have a higher wet boiling point because it absorbs less moisture. This is good, as less moisture means less corrosion and longer maintenance-cycle intervals."

Silicone Brake Fluid, part 1

Silicone Brake Fluid, part 2

One warning about the third item above: about one month ago I had a master cylinder failure using silicone brake fluid. The master cylinder was new (about 1500 miles of use) and compatible with DOT-5. On a trip to a vehicle show in Dedham, MA I lost pedal pressure.

When I tried to bleed the brake lines/cylinders, I noticed that the MC piston was not returning. When I removed and inspected the MC, it was clean but I had a little difficulty removing the piston.

The problem was that a little oil/grease was in the cylinder and it did not mix with the DOT-5 fluid; moreover, the oil/grease was in globules that caused enough "friction" that the piston spring could not return the piston. I cleaned it throroughly and every is now fine.

The oil/grease contamination must have been in the MC from the factory. All brake system parts were new and the parts were installed by me during a frame-off restoration (in fact, the body was off the frame and the brake-system installation was done on the completely cleaned/restored rolling chassis). I will now take apart, inspect, and clean with alcohol all new master cylinders, brake cylinders, and brake lines.

Tim

DOT 3 absorbes the moisture in the brake lines. When your vehicle sits for long periods of time, the moisture attracted to the wheel cyclinders, etc., and that is what corrodes them so bad.

DOT 5 works to remove air from the brake system. It is probably better for long storage times because it attracts less moisture.

The rubber components have to be compatible for the fluid you use. The white and yellow paint markings on the rubber components in a new kit help determine whether it is compatible with DOT 3 and/or DOT 5.

On the old Volvo cars the DOT 5 will eat away some brake parts. I would be suspicious about the same problem on most older vehicles. I have switched to Castrol GT LMA with no problems for over a year now.

Castrol LMA