Hey ya'll, I've been trying to get my '54 Chevy's brakes to fully pressurize. I've replaced the master cylinder, wheel cylinders, lines, and all shoes and springs. I am not getting any more air out of the line but the brake system seems to not fully pressurize. After going through all of the usual troubleshooting I have a question: Is it possible that the 4 wheel cylinders are fully extending but the shoes aren't fully contacting the drum to the point where there is pushback on the brake pedal....and could this be caused because the self-adjusters on all four drum are installed in the fully collapsed position? Should I extend the self-adjuster out to take out some slack? I can hear all of the shoes moving as I push the brake pedal but the pedal does not get firm, and the shoes do not firmly stop the wheels from turning. I hope all of that makes sense. I've attached a picture of the set up, and the springs were all attached after the pic was taken.
The adjuster is all the way retracted. How old are the drums? Have you measured the inside diameter? The process I do- once all the air is bled, apply the brakes to "center" the shoes in the drum. Rotate the wheel and expand the adjuster until there is a slight drag on the drum. Repeat for the other 3 wheels and test the brake pedal firmness.
Yes, you need to adjust the shoes until they contact the drums for there to be pedal pressure, otherwise you're basically doing the same thing as pressing the pedal with no drums on at all. I also adjust them, spin the drum, and repeat until I get light dragging. Do them all the same as to not get pull when applying the brakes.
First off, you do not have "self adjusters" on those brakes, you HAVE to adjust them yourself. Just about exactly 62 years ago I was taught to adjust the shoes up until you can't turn the wheel by hand and then back the adjuster off ELEVEN clicks. That has worked on the hundreds of drum brake brake jobs I have done since then as I worked as the front end and brake mechanic in a Firestone store and other shops when I was doing mechanic work. As others said, that should have been done before you started bleeding the brakes. You want a little drag on the drums with the shoes. Don't listen to the bullshit artists that say you don't want any drag at all.
Not to just pile on here, I've seen this before and it ain't as I was taught by guys who have since gone to their grave. Run the the adjuster ( with spoon ) tight 'til the wheel won't turn. ) to fully seat shoes. ***Then back off the adjuster, til there is light ( audible ) drag. Then bleed. Also I can see no sign of any lube on the adjuster screw. A light coat of grease on the threads will be welcome when re-adjusting in the future. Mr48chev always knows
They are hell to put on until you learn the trick of attaching the bottom of the spring to the pad assembly, looping a screwdriver thru the top hook of the spring, resting the screwdriver blade on the top eccentric and sliding it on. Easy peasy.
Also remove some fluid from your master cylinder before all this or your firewall is going to wear it once it overflows.
I adjusted hundreds of drum brakes when working at a Sears Auto Center. I was taught by their 2 brake men. First and for most the shoes need to arced to fit. Since the machines are outlawed I do each one by hand on mounted in a vice with a body file or wood rasp. Adjust with the star until tight and drum will not turn by hand, back off 7 clicks. Then bleed if wheel cylinders are new or rebuilt on the car. Easy peasy nice and easy…
Those are not self adjusters. as a starting point adjust the shoes out until you can just slide the drums on