Hi.. I'm having a brake problem, i think, and need some advice what to replace instead of doing a "replace all" thing. My 74, brakes fine, 4 wheel drum, but when at a light i have to keep a lot of pressure on the pedal to keep the car from creeping forward... the carb was rebuilt and the idle and choke are fine. You think it's the master or should i replace all 4 wheel cylinders?
is it power(vacuum assist) brakes or manual? does the pedal fade towards the floor or stay solid when you start to roll?
if you dont have fluid leaking from a cylinder (wet spot on the back plate the cylinders mount to) and you dont have a fading pedal, i would say you probably have air. usually if it is the master you will get pedal fade. bleed the cylinders, making sure to keep adding clean fluid in the master cylinder. you should check the hoses and lines while down there like bluegene mentioned as well as they can also be kinked or cut by road debris.
Does the fluid in your M/C look like old burnt coffe and smell worse??? If so you probably have corrosion in the M/C as well as wheel cylenders from moisture.(brake fluid will suck the moisture out of the air)Have you done any work to the brake system on the car???It sounds like the M/C isnt doing its job or you have frozen front wheel cylenders.Check em out.Deterriorated hoses will usually cause the opposite effect...(brakes wont release) If your hoses are original...I would replace them anyways.They cant be too good after 30 plus years of use.
definately in any way of what the problem is now, if the cylinders and hoses are not all new replace them when you can afford it. the parts are fairly cheap and its about the most important part of the car. also look at replacing the springs and cables in there
I'm gonna go a long with air in the Master Cylinder. The only way to get it all out is to bench bleed.
Sorry to disagree. You can get the air out of a master on the car. It gets on the car and it's not as easy, but it can be done. Air is not the problem here, that creates spongy and loss of pedal. There has to be a problem with a componant. Initialy mentioned was a carb rebuild. This makes me think vacuum issue to the booster. I don't see the relation otherwise. Was said it is manual brakes so the wheels need to be removed and the brakes inspected for a visual as to the conditions of all the componants. I have also seen where metal to metal will cause a not holding condition on drum brakes.
When you inspect the brakes be sure to pull the rubber covers on the wheel cylinders back and check the cyl bores. Two of my wheel cyl were siezed with corrosion.
Yes I know you can bench bleed a MC on the car as long as you use the same procedure. I install a new MC without bleeding it good and it had a hard pedal. Once it was properly bleed it worked like it should. Air in the line or wheel cylinder will give spongy or loss of pedal. I agree the whole system needs to be looked over because something is wrong. Either mis-alignment, rust, moisture in the fluid or faulty components.
did it have this problem before the carb rebuild? what is the idle speed set at right now? Does it come to a stop fine but just hard to hold at the stop or is it hard to stop?
