I have just rebuilt the front axel, springs and brakes, all stock. I installed an under floor aftermarket brake booster with dual master cylinders and front and rear residual valves of different pressures as recommended. The brakes grab on one side and pull upon application. I am at a loss for the reason. Repeated adjustments and a thorough inspection show no help. I did paint the inner brake shoe mounting plates and wondered if the shoes are sticking on the paint, but seemed ok when I moved them by hand. Any suggestions Ps, the brake pedal goes down about ¼ of the way before the brakes apply, but I have the push rod adjusted with no free play.[
Did you have the shoes cam ground to match the drums? If not take the shoes off and lay them in the drum and see how well they contact the drum, if only 20-30% contacts then you have found your problem. ALso any grease on the shoes can cause the problem you discribe.
Like Coupster sez: Cam ground shoes should 'rock' a little in the drum, not a lot! Hand check, each shoe should have no more that .010" clearance at one end. A 'mechanic' friend of mine did shoes & drums on a '31 Phaeton I was wiring for his room mate; Mechanic was about 7 beers down, and mixed up the drums with the arc'ed shoes. Road tested it and ran right into the curb when braking! (his room mate thought it was the beer) but we juggled shoes/drums for a nice straight stop.
I like the idea of grinding the shoes but I can't find anyone that can do it in the Springfield Ma. area. I think that a Model A shop on Coledge highway in So. Hampton does it but I can't remember the shops name. Anyone know of him?
seems to me that if you have drums that are within spec, and fresh shoes, then you will not need to re arc the shoes, they'll fit close enough. How much oversize are the drums? you put the long shoes on the rear, short on the front, of each wheel, right? did you use new springs? everything's clean? all the suspension hardware is tight and properly installed?
Squirrel, I have done everything that you posted. They seem to be touching on all of the shoe except small low areas all over the shoe. I think the drums are new but they had rust on them from the old shoes touching them for years in the field.There are slightly out of round as turning them by hand shows. One side is tight even though it is backed off all the way. That in not the side that is pulling though.
Did you replace the rubber brake hoses?,,age will make them soft on the inside but appear OK with a visual inspection. HRP
I'll second the brake hose suggestion. My 56 was all over the road under hard braking untill I replaced the front hoses. Stops straight as an arrow now.
Consider that the problem may be the opposite of what you think it is. In other words, the wheel that is pulling may be doing its job exactly correctly and the other wheel is not functioning. That gives the illusion that one side is pulling. Check the other side to see if the wheel cylinder is leaking, causing those shoes to be slippery. even new (chinese!) cylinders can leak Look at the grease seal to see if its allowed grease to make those shoes slippery. Pull the not-working drum and press the pedal to see if the shoes are actually moving Check obvious things like---have you bled the brakes? Under floor systems can have a high point in the system trapping an air bubble
Both drums are clean and shoes go out and retract OK with the drums off. I am also concerned that I must push the pedal down about 1/2 way before the brakes start working although there is the very smallest amount of play in the pedal to master cyl. push shaft.
The side thats not "grabbing" is backed off all the way? Well of course its gonna pull toward the adjusted side if the other side is backed off completely. What your saying is pretty much impossible if everything is actually correct inside the drums. In my opinion, something other than shoe friction material must be causing your brake to be tight on that side. Pull it apart (Both drums only first) and get some pictures posted. I think you have something put together wrong or have mismatched parts. Thats what I'D start looking for anyway... BTW...starting with KNOWN out of round drums is a complete waste of your time.
My first thougt is your brakes are not correctly adjusted. That would show in the low pedal. Some Bendix style brakes have adjustable anchor pins that also must be adjusted when new shoes are used. If there is a large nut above the wheelcylinder you have adjustable anchors.
Quote Hackerbilt,"The side thats not "grabbing" is backed off all the way? Well of course its gonna pull toward the adjusted side if the other side is backed off completely." What I meant by that is that the lf shoe is tight and I can not back it off because the adj is screwed in all the way. "Yesterday I backed way off on the rt front shoes and it seems almost right now. A few more miles on it may improve it where I can re adjust them.
Quote from this thread "I think the drums are new but they had rust on them from the old shoes touching them for years in the field.There are slightly out of round as turning them by hand shows. One side is tight even though it is backed off all the way. That in not the side that is pulling though." I tryed to get the drums turned even though they seemed like new. They could not even get the L. front drum set up on the machine because it was so far out of round! I bought two brand new drums and told them to turn them, that should fix it.
One way to eliminate the problem of it being the drums is to switch them from side to side then drive it. If it still pulls the same way you know its not the drums.
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