Brake Problems 76 F250
New User
Joined: Jan 2000
Posts: 13
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Brake Problems 76 F250
Hi, I've got a 76 F250 with a Dana 60 frontend in it, new calipers on both sides, new master cylinder, new/used proportioning valve, and new skyjacker ss brake lines. What happens first is that the truck pulls to the left under braking, then after a few minutes of driving the pedal is rock hard and can't be pushed down, and the brakes are locked up. I've had 2 different new master cylinders, same problem, had the problem with old calipers as well as new, same with the proportioning valve, so I'm kind of baffled. Any ideas???? The truck runs 39.5 boggers just for reference. Thanks! Brett
Post Fiend
Joined: Feb 2000
Posts: 5,130
Likes: 8
From: Brea CA
Brake Problems 76 F250
Brett, as far as the brakes locking up, it sounds like your master cylinder may not be fully retracting to the rest position when you let off the brakes. Check your brake pedal assembly to see if it has unrestricted travel to the return position and is not hanging up on the stoplight switch. If the pedal is working correctly, look at the pushrod inside the power booster. There should be a gap between the end of the rod and where it inserts into the plunger of the master cylinder. This is hard to measure but sometimes you can detect the clearance by slightly pushing down on the pedal with your hand until you feel the rod bottom out in the master cylinder. Do this with the engine off and all the vacuum drained from the booster as the power-assist will mask your efforts. If you don’t feel anything, go ahead and shorten the length of the pushrod inside the power booster by turning the adjustable tip clockwise a turn or so. Make sure you first soak the threads with a penetrant and slowly work them loose or else you will surely snap it off and really make your day.
Barry
Barry
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Brake Problems 76 F250
I concure with BBB, I had a simular problem when I installed the power brakes on my truck. The rod coming from the booster had to be turned in a little to allow the full release of the brakes. The last time, I drove the truck before correction, I had gone a few blocks and it seemes like the brakes were on, I turned into the Home Depot lot and one of the wheels started sliding and the pedal was rock hard. I let it cool, backed off the rod and it has been happy every since.
John
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
John
66 F100s
In the still cool hours of the night, you can hear chevys rusting away.
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