Mushy brake pedal

D

don-wi

Senior Member
Last year I redid the brakes on my 47 Tudor. I installed new wheel cylinders, shoes, new hoses and also a new master cylinder. The brakes worked good but it always had a pedal that was not real firm when stopping and holding the pedal. I could lock up tires on gravel. Forward to this year, I had to pull rear end to install rebuilt transmission and new clutch. I figured that I would start fresh and adjust all the brake shoes first, then I checked the push rod for the master cylinder to make sure that I had free play between the end of the rod and the master cylinder piston. I connected my power bleeder and went about getting good fluid through all the bleeders. I did the right rear, left rear, right front and then left front. I did them and let it sit awhile and went back and did them again. When I push the pedal the brakes to all the wheels lock but the pedal feels a bit mushy. Pumping them doesn't change things. The pedal also does not fade away. When I adjusted the shoes I turned the adjuster until the wheel wouldn't turn and then backed it off so I had a light drag of the shoe against the drum. I did both adjusters on each wheel.
Thanks,
Don
 
Any chance you are using silicone brake fluid? The silicone fluid will trap air bubbles and give a muchy pedal if you are not extremely careful. I have always bled my brakes the old fashioned way (what is this "power bleeder) and never had problems. Try it the old fashioned way. Two people. One with a wrench and the other to pump. Pump them up, open the bleeder, allow the pedal to slowly go to the floorr, close the bleeder and pump them up again. After bubbles are out go to next wheel cylinder. Repeat until firm.

Charlie Stephens
 
I'm not using silicone brake fluid, I'm using standard DOT3 fluid. The power/pressure bleeder that I'm using comes from Motive Products and I have had good luck with it. I have a 2ton truck with a hydro-vac on it and a pressure bleeder is required to bleed those systems effectively. I usually work alone so having a one man operation to bleed brakes is also another bonus. I'll find someone to help and bleed them one final time the old fashioned way.
Which wheel do you guys do 1st and 2nd and so forth?
The other thing I'm going to check is the amount of free play I have on the push rod that goes into the master cylinder. I still have the floor pan out of the car so the brake pedal is actually coming up higher than normal because its not stopping against the toe board. Not sure that would matter but????
Thanks Don
 
Your lack of toe board in place (allowing pedal to come-up higher than normal) will most definately make it about impossible to realistically or accurately measure for the proper 'free play'. DD
 
you say you have a hydovac is the diafram over 5" if it is you schould not have a check valve in the master cyl. if you do remove it
 
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