I can not for the life of me get my brakes to work properly 1st front brake are f 100 Rear are 47 ford 1967 chevy master cylinder I have bench bleed the master cylinder twice bleed front and rear more times than I can count and the pedal still goes almost all the way down. so today I blocked off both front and rear brake line at the master cylinder it had a firm to the top pedal next hooked up just the rear brake line bled it till just clear fluid and still pedal goes down to the floor and no I did not arc my shoes but they are dragging pretty tight so not sure what I have done wrong front brakes at this point are plugged off till I can get the back working Thanks for any help
First make sure that you have zero leaks in the line. Now that you have pumped the brakes once or twice bleed them again and see if you are getting air in the line. Next make sure that you are actually getting full travel on the piston in the master, sometimes the brake shaft ( from the peddle) isn't long enough. Sure its good enough when there is no slave or lines to make up for. Also make sure that the brakes are ***embled properly. I stole some pix the other day. The short shoe goes on the front by the way. OK you already know all that just being through. Good luck
Sounds like a fluid volume issue to me or lack of that is. You have 2 very large wheel cyl's on the rear. They take X to make them work correctly. Your GM master is moving less than the 46 Ford one did so it takes more movement at the pedal to move the correct amount of fluid to get the job done. Now if you used 3/16 line instead of 1/4 there is another restriction of volume. Volume and pressure are two different things and both need to be correct to get the job done. The stock 46 Ford master moved more volume with less pedal travel than your GM does so there in is another issue. The Wizzard
Seems to me that Ford used bigger slave cylinders that GM like about forever. I am tweaking my brain now that you brought this up and it seems like we used to use Ford truck masters when we were going from single pot to dual. ( 50 years is a damned long time ). I got a peddle master setup in the garage for a '36 Ford that I bought for some reason and it uses a Ford master. Anyway like the Wiz... brought up it may very well be a master cylinder piston size that is the problem.
F.Y.I. Look at a stock 46 Ford brake pedal and the ratio of push rod to foot pad. Now look at all the after market replacement pedals. What do ya see? Picture getting Brighter yet? The Wizzard
Don't remember the ratio but know there's Right and then W.T.F? when it comes to ratio and works right. I think roder1935 is going through the latter. The Wizzard
I know, sometimes we just under think it. One extreme or the other on the HAMB they are either over thinking something or under thinking it. No one ever seems to stay middle of the road.
The Ford master is 1.062" diameter, the Chev is listed anywhere from 1", 1.125", 1.25". Depends on which one you buy. Even with the smallest Chev master it's only .0625" smaller then the Ford. I wonder if the Chev master is not getting full stroke. Also no mention of a proportioning valve/combination valve in the system. If there is one maybe is't bad or not centered. Or plumbed wrong.
With old Ford brakes it seems to be most important to adjust the shoes BEFORE worrying about bleeding. Then, after the fluid is flowing and you've tested them on the road, fine-tune adjust them again. And if the arc of the shoes is way different than the drums, you will need to adjust as the shoes bed in.
Just read threw the major adjustment and I have not done that so that is where I will start Thank you
While thoughtful, the diagram/procedures in ******'s attachments only apply to '39-41 brakes. The '42-48 brakes don't have adjustable pivots at the bottom, but you do want to make sure the eccentrics move freely.
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