1940 Brake Bleeding
 

Got everything reassembled and I have filled the new master about 20 times and still no hard pedal. Using speed bleeders. Does it normally take this long to get a firm pedal ? Am I doing something wrong ?

I only replaced the front cylinders and shoes.

Thx....Mike

Re: 1940 Brake Bleeding
 

Not certain if you are doing anything wrong or not.

Did you have a good pedal prior to replacing the shoes and cylinders? If so, we can pretty much eliminate a defective master.

You must start at the right - rear cylinder. Bleed that and move to the left - rear. Then the right - front and finally the left - front.

Be 100% certain the master NEVER runs low. If it does, you will instantly introduce air in to the system.

Speed bleeders? If the method I'd just described does not work, I'd suggest you remove the speed bleeders and get a helper to manipulate the brake pedal.

Pump the pedal at a "normal" pace about five or six times and HOLD it down until you have opened and subsequently closed the bleeder. Check fluid in master and top off as necessary.
Repeat.

Re: 1940 Brake Bleeding
 

Did you bleed all 4 wheel cylinders? Look up previous threads on this subject.

Re: 1940 Brake Bleeding
 

It looks like Kube replied ahead of me. Follow his advice.

Re: 1940 Brake Bleeding
 

Speed bleeders generally only require 2-3 slow pumps to purge the line and then close the bleeder.

Is the pedal to master cylinder rod correctly adjusted?

Re: 1940 Brake Bleeding
 

I did not start in the rear which I will do now. The pedal goes right to the floor and i did have hard brakes before but some of the cylinders were frozen. New cylinders in front only. I have no leaks anywhere. Are you saying to shut off the bleeders each time i fill the master ? I must have filled the master 20 times and nothing yet. I screw the cap on each time, but pedal goes to the floor. I’ll check to see if it needs adjustment next. I’m keeping the master filled the best i can. I do have one drum off right now. Should i reinstall it during this process ?

Thx mike

Re: 1940 Brake Bleeding
 

Mike: Are you using the correct procedure for bleeding all for wheels? Yes, you do shut off each speed bleeder each time you fill the master cylinder and Yes, you must bleed the brakes with the drums on the car and brake shoes adjusted so the shoes are not retracted far away from the drums .

Too far away and the shoes will not give any resistance to pedal pressure. That's the way I do it. In fact, I adjust the brakes BEFORE I bleed them to avoid this problem.
As you may know, you do them in this order:
LR, RR,LF, RF. Here is a helpful video.
https://www.youtube.com/watch?v=3VMV51FUA7A

Here's what the Speed Bleeder folks say:
http://www.russellperformance.com/mc/speed-bleeders/

Re: 1940 Brake Bleeding
 

You have to shut OFF the bleeder after each time you bleed the line.
That is, slow pump to get fluid in the catch can.
Then close the bleeder and then proceed to next line and do the same.
Fill the master as required.
( I supect that you never closed the bleeders)

Re: 1940 Brake Bleeding
 

You can't bleed brakes with the drum off, so that would be a place to start. There is nothing for the brake shoes to push against.

Re: 1940 Brake Bleeding
 

Really? All you are doing is bleeding air from the line, does not have to push on anything.
The return springs are sufficient.

Wonder how one manages to bench bleed master cylinders without brake shoes.

Re: 1940 Brake Bleeding
 

I believe my quote is perhaps the best way I am able to respond...

Re: 1940 Brake Bleeding
 

Okay back to square one. No I didn’t put on a drum. No I didn’t start at the rear. No I didn’t shut off speed bleeder after each time I filled the master. Will do going forward.

I’m going to have a Jack Daniels and start all over in morning.

Thx........Mike

Re: 1940 Brake Bleeding
 

Re: 1940 Brake Bleeding
 

Mike, wish you were my neighbor.

Re: 1940 Brake Bleeding
 

You are a twisted man!

Seriously though...you and I would have fun :)

Re: 1940 Brake Bleeding
 

Jack and I have been good buddies for about 40 years ! Some guys see a shrink......but I have him to talk too. Works for me !

I’ll be in the barn in the morning getting back into it.

Thx.....Mike

Re: 1940 Brake Bleeding
 

Ok, I will modify my post. I have never attempted to bleed brakes without the drums on and the way I bleed them it would not work. I put a lot of pressure on the brake pedal, and thus the hydraulics, and it would over power the return springs.

Re: 1940 Brake Bleeding
 

I BELIEVE Jim was referring to "mike42", as HE had the "Jack", Jack! You just do that ol' Korbel Kool-Aid!

https://th.bing.com/th/id/OIP.0gxIsa...A?pid=Api&rs=1

Re: 1940 Brake Bleeding
 

Really? The return springs are sufficient FOR WHAT? They're NOT sufficient to retain a wheel cylinder's pistons and cups if someone unfamiliar with the general procedure (as "mike42" readily admits to) attempts to 'stroke' the pedal TOO far when a drum is NOT installed so as to limit piston travel created via pedal over-stroke.

Another thing that anyone bleeding brakes should be aware of is NOT to stroke the pedal such that the piston bottoms-out in the MC.

Bench bleeding has NOTHING to do with brake shoes. The process is intended ONLY to completely void the circuitry within the MC of any air.


DD

Re: 1940 Brake Bleeding
 

How much pressure is being is being exerted on the wheel cylinder when the bleeder is open and the brake pedal goes to the floor?