40 brake dilemma

Thanks everyone for your time, advice and suggestions. I will let you know if and when my problem is resolved.

Warren
 
warren va said:
Thanks everyone for your time, advice and suggestions. I will let you know if and when my problem is resolved.

Warren
Click to expand...

It is very interesting that the problem seems to be isolated to one wheel and I think you said you changed the wheel cylinder on it at least once? I will be interested in hearing what you figure out.
 
Finally readjusted shoes and Gravity bled [ silicone fluid] in wheel cylinders. Brakes working great now after 4 weeks of aggravation.
Thanks everyone for your help. :)

Warren
 
There seems to be a problem when people use DOT 5. DOT 5 is an excellent brake fluid for cars that do not see a lot of use to drive the moisture out of the fluid. DOT 5 is a slightly different animal than DOT 3. NEVER shake the container of DOT 5. You will create microscopic bubbles that take a long time to settle out. NEVER vigorously pump the pedal when bleeding. This will create bubbles in the fluid. Make good double flair joints if you are replacing the brake lines. Don't be afraid to tighten the tubing fittings and the bleeders. The DOT 5 molecules are smaller than DOT 3 and can find their way out of just snug fittings and slightly off flairs.
 
I don't know where I heard or read it, but I remember from somewhere that you should heat Dot-5 fluid almost to boiling to drive out the air bubbles. I changed my O/T '68 Corvette to Dot-5 several years ago, and I did this using a cheap tea-kettle from the dollar store. Also, I was careful carrying it out to the garage so as it not to agitate it and encapsulate air. Bleeding the brakes on that car was a slow process, but I finally got it done. It was such a pain in the butt that I have gone back to using Dot-4 on the cars I have done since then. I guess Dot-5 is very susceptible to absorbing air (which I guess is better than Dot3/4 absorbing water).

Anyway, the brakes work great in it, but unless something strange happens with the other cars, I probably wouldn't do it again.
 
On my 39 Standard,changed all 4 wheel cyls. installed new shoes, drained Master, broke all lines at cylinders, pushed some dot 5 thru system to clear lines, then reconnected lines to cylinders, tightened all bleeders. Filled master slowly. Bled system , one guy slowly pumped brake pedal,other guy opened bleeder. That was 2 years ago, No problems doing the job, and no problems since. A friend was very helpful in getting me to do this. He said he was sick of parking a car in fall, and finding rust / cylinder failure in spring. He had used dot 5 in several cars. I was expecting problems, at the time, but everything went smoothly with the exception of those crazy adjuster cams! But we figured it out. I shouldn't admit this, but I have not checked the Master since redoing the brakes, Will do it tomorrow
 
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