1951 ford brake problem....help

L

lonewolf

Senior Member
hello im working on a 51 ford victoria and im having brake problems and im ready to pull my hair out.......its all stock except it has has silicone brake fluid. it has 4 new wheel cylinders and a new master cylinder(it was sitting in the trunk of the car for 20 years) I had to get rid of the pressure brake switch because it was always made or on. I tried a new one and it did the same thing. so i put a mech lever one on. it has a new cap on the master cylinder......

the problem is that when i drive the car more than 10 miles the brake pedal gets rock hard and looses its 2-3 inches of free play and i have to stand on the brakes to stop. when the pedal is rock hard if i loosen the front bleeders it shoots out fluid like your standing on the pedal. when the car sits over night it goes back to normal. slso if it sits over night the brakes shoes dont rub on the drums if you jack it up and spin the rims.

do you think its the fluid or is there some kind of problem with the mater cylinder? thanks
 
2 possibilites - adjustment of the plunger rod on the master isn't letting the plunger come all the way back or the brake hoses have a restriction inside that doesn't let the fluid return.
 
It is obvious that the push rod is too long.
That's why the stop lights stayed on, that's why the brakes drag.
You must shorten/adjust the rod so that you can move the pedal without pushing on the master cylinder piston. Any amout is enough. Say 1/16 inch at the master or an inch at the pedal pad where you put your foot.. The piston has to move back enough so the fluid pressure can be relieved back into the masyter cylinder where the fluid is poured. When you drive the brakes warm up and the fluid expands.
 
Also check the position of the rubber stop sleeve on the brake arm to the floorboard. On my 51 it had moved and wouldn't allow the pedal to retract all the way back thus taking up the slack to the master cylinder.
 
I could be mistaken but I am pretty sure that you can't mix fluid type. Using the silicone fluid or dot 5 causes the rubber to swell or shrink. That could also be why the brake switch stays on.
You need to start from scratch and replace and/or rebuild all components including rubber hoses and refill with dot 3 or 4. That should fix your problems or at least give you a good start point.
 
Last edited:
lonewolf said:
hello im working on a 51 ford victoria and im having brake problems and im ready to pull my hair out.......its all stock except it has has silicone brake fluid. it has 4 new wheel cylinders and a new master cylinder(it was sitting in the trunk of the car for 20 years) I had to get rid of the pressure brake switch because it was always made or on. I tried a new one and it did the same thing. so i put a mech lever one on. it has a new cap on the master cylinder......

the problem is that when i drive the car more than 10 miles the brake pedal gets rock hard and looses its 2-3 inches of free play and i have to stand on the brakes to stop. when the pedal is rock hard if i loosen the front bleeders it shoots out fluid like your standing on the pedal. when the car sits over night it goes back to normal. slso if it sits over night the brakes shoes dont rub on the drums if you jack it up and spin the rims.

do you think its the fluid or is there some kind of problem with the mater cylinder? thanks
Click to expand...

If your shoes are adjusted right and new wheel cylinders,take a look at the rubbber hose and see if its been pinched.What some guys do is pinch the line and have less to bleed and don,t get it on the floor.Some times you can get away with it but the line can be damaged. The master cylinder from sitting 20 years maybe the problem.
 
Everyone that pointed to the master cylinder or the rod adjustment are right on target. Go there first. The bleed hole in the master cylinder is either not exposed due to the rod being so out of adjustment, or there is rust in there plugging things up. I'd bet on the adjustment. It definitely is in the master. The fluid is of no consequence. There are people out there that needlessly blame DOT5 for everything. Also, I have never seen DOT5 affect any rubber brake component other than brake light switches.
 
Russ you are right on with the brake problem. I use the dot5 and no problem.And I have switched one to another and no problem in my 49 Merc.
 
Change the 3 rubber hoses and you should be OK. If your master is not returning, change that also.
 
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