C-1 Brakes

[Bwmurph]

Hi All,
I've recently become unhappy with the brakes on my '59. Several years ago I had a Studley's IFS with non-power disc brakes installed. My mechanic at the time used DOT 5 (silicone) brake fluid. The car seems to be increasingly hard to stop and i have to really stand on the pedal to "lock up" the wheels. Its to the point where its uncomfortable to drive.
So ... I thought I would bleed the brakes and see if that helps; went to get my Motive Power Bleeder and the nipple on the pressure block broke off as well as all the hoses cracking. Hoses were fixed easily but tried putting a brass nipple in the pressure block using JB Weld - unsuccessful. So I'm just going to order a new one from Motive.
Here's my dilemma: I haven't liked the silicone fluid from Day 1 and today I notice on the Master Cylinder cover that it says use DOT 3 fluid only. I would like to switch back to glycol, but I understand that is a real PITA. I've read that you will have to disassemble everything (master cylinder, calipers, etc..) to properly clean all the silicone out of the system. Is this true ? Can I just run alcohol or some other solvent through the system to cleanse it ? I REALLY don't want to take everything apart if I don't have to.
Any suggestions will be appreciated.

Also, if anybody is interested, I still cant get my drivers side seat to go back far enough to suit me !
Bernie O

 

[Tom Bryant]

When I was in GM Parts we had a GM brake system cleaner in quart or larger cans on the shelf. It was a system cleaning solvent. I'm not sure if it was alcohol or not but something similar. You cleaned out the master cylinder reservoir then poured the solvent into your pressure bleeder or master cylinder. Then opened the bleeders until there was no trace of old brake fluid coming out. Next step was to put new brake fluid into your bleeder and repeat until all of the solvent was gone and only clean brake fluid comes out. There is an element online that runs in circles panicking about even a trace of Dot 5 in a brake system while spouting all sorts of claims of doom and disaster. My wife's 81 has had Dot 5 in it since it was new without any performance related problems yet.

I found a gallon jug of Blue Mountain Brake System Cleaner online that sent me to a dead end at Ebay That sounded like the brake system flush cleaner we used to use. I'm not sure if the auto parts stores or GM dealers have the system cleaner on the shelf or not. I'm confident that a thorough flush with cleaner and a refill with Dot 3 will do the trick. Back to the 81, two years ago I put on new Bendix carbon ceramic pads and flushed/bled the system with fresh Dot 5 and the brakes on that car have never been better. When you go under to bleed the brakes have someone pump the pedal to verify that all of the caliper pistons are moving. It also could be a problem with the proportioning valve.

Tom

 

[Bwmurph]

Thanks Tom ! I figured you would be the one to reply and also to have some extensive knowledge on the subject!
I’m out of country right now but will attempt to bleed the brakes with my Motive Power Bleeder when I return home next week.
If I can get a nice hard pedal and a decent stopping distance with the DOT 5 I will leave things as is. I’m also going to look into upgrading to power brakes.
Stay tuned. Thx again !
Bernie O

 

[Bwmurph]

Thanks Tom ! I figured you would be the one to reply and also to have some extensive knowledge on the subject!
I’m out of country right now but will attempt to bleed the brakes with my Motive Power Bleeder when I return home next week.
If I can get a nice hard pedal and a decent stopping distance with the DOT 5 I will leave things as is. I’m also going to look into upgrading to power brakes.
Stay tuned. Thx again !
Bernie O

OK I definitely decided to go the power brake booster route. I think I read somewhere that you need at least 18 in/Hg to operate the booster correctly. I just checked my car ('59, GM Crate, 350/300, original WCFB dual quads), and I have 20-22 in/Hg at idle and differing readings depending on RPM, but all above 20 in/Hg, So, unless anyone tells me different I think I'm fine in that regard.
I think I'll also go back to DOT 3 brake fluid at that time as well. Again, unless anyone can convince me otherwise.
Any and all comments, suggestions, etc...are welcome.
Bernie O

 

[Tom Bryant]

Sounds like you will be fine with that. I don't know what pad compound you have on your car but you might try a new carbon ceramic to see how that feels.

Tom