Here's a shot in the dark. I had a similar problem on my model A, but I have discs on the front and drums on rear. When I pushed on the pedal, it went about 3/4 of the way to the floor, but I had some brakes. Not that good, but some. I figured I would try a bigger master cylinder, so I did that and it did improve the situation some. When I was trying some different calipers on the front end, my buddy and I were bleeding the brakes. Now I have to admit that this is gonna make me sound real stupid, but here goes anyway. Peter, from inside the cab, I probably need to top up the m/c now. Me saying ok, from underneath. Peter then says, how come the small reservoir is almost empty, and we're bleeding the front brakes? Me, starting to laugh, suddenly realizing what was wrong all along. Feeling stupid, I switched the lines. I thought I knew my brake system, but I guess I didn't. Once bled, I instantly had wonderful brakes, and could lock them up with very minimal effort, or pedal travel. You stated you had a big and small reservoir master cylinder. I thought I had mine plumbed properly. Is it possible you have your small part of the m/c plumbed to the front like I had? Just a thought. Good luck.
Doing mine tomorrow. Juice brakes, single master, Repop wheel cylinders and the correct bleeder screws. The bleeders make it easy to get the air out and it also keeps your backing plate paint from getting screwed up. No residual valves. Don't expect a problem. Last one I did was same pieces and no issues. Posted from the TJJ App for iPhone & iPad
Where do you get those bleeder screws? What happens if the rubber seal on the screw goes bad and you have a single resivoir master cylinder? What is the airspeed velocity of an unladen swallow? African... Sam
Your wheels are turning one full turn on your adjustment? Got an e brake? Set it just slightly and try your brakes, I think a full turn is to much. Tighten till they just start to drag. Ever drive and old car that you had to pump the brakes to get stopping power? the shoes are to far away from the drums. adjust,might add they have to wear in. Used to cut to fit the drum a long time ago.
Those are correct 39-41 bleeders and the fitting to bleed them. They lock down and seal like a normal bleeder, the screw and gasket are just there to keep dirt out of the hole. You put a rubber hose on the fitting and run it to a container of brake fluid and pump them, lock the bleeder down, pull the hose and fitting. Got them from: Roy Naciwicz (734) 654-9450 He makes the best early ford nuts, bolts, fittings etc.
Fairly logical really, Mr Eastwood said it in a nutshell right at the beginning, Mastercylinder size, 42-48 wheel cylinders have 2 different dia pistons, a lot of volume, the speedway 1" mc most likely suits the later single dia pistons like on spinners and F100, the bendix style brakes, you will need more volume for the earlier brakes, bigger diameter, try the original size m/c bore for those wheel cylinders, bet it does the job
I have seen 3 things cause a huge headache for brake mods. Incorrect MC bore size, Air stuck in the system, Not properly bench bleeding the MC before installing (which makes #2 worse) Vacuum or pressure bleed (mitivacs are about $30 at harbor freight) and dont forget to bench bleed the MC after verifying the correct bore size and pushrod adjustment
The Jalopy Journal
