Howdy guys, and gals. I have a concern on my 1940 Chevy stock brakes. When I hit the pedal it goes to the floor, and there is hardly any pressure. But after a few pumps it gets pressure again for awhile then goes back down. I just put in a new master cylinder and all lines, shoes, and drums are new. And as far as i can tell so are the wheel cylinders. I thought of to keep bleeding them with new fluid? And i also know that the pads need to be adjusted. Can yall give me your input?
Those were the same symptoms of my cad before I replaced the wheel cylinders. Pull back the rubber on the ends of all the wheel cylinders to check for fluid/crud. You very well may need to rebuild/replace them If theyre clean and leak free then Id agree to adjust the shoes outwards some more and rebleed everything.
Cool i will investigate tonight. The previous owner started a frame off resto. He did all new lines pads drums, so i dont see why he would not have did the wheel cylinders. The only thing he did not have was a master cylinder. Posted using the Full Custom H.A.M.B. App!
Adjust the brakes first !!!! The master cylinder can't pump enough fluid to fill in un adjusted brakes in one pump. Takes a couple But then the springs at the shoes can push it all (2-3 pumps) back into the reservoir. If it were just air, the pedal would never be hard and there's no way to get ALL of the air out if the pedal doesn't firm up on one pump
Bench bleed it, then keep bleeding it on the car until it's good. When you replace everything, or even just all the brake lines, it takes a loooong time to get all the air out of the system. A power bleeder would work even better, if you can borrow, or make one. I made one with a piece of steel plate, all-thread bent into U shapes, and an air fitting and regulator.
I've never needed to bench bleed an old single unit master cylinder. that's something you have to do on modern dual cylinders to get them started. A simple brake shoe adjustment will probably solve it
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