ridgerunner
Full Access Member
I need to get some helpful advice from the seasoned Ford diesel owners. I've got a 92 F350, just completed a engine swap, truck had sat for @ 4 years. No brakes, hard pedal. So, I replaced front brake calipers, flex line, master cylinder, brake booster, rear wheel cylinders, shoes, got a good bleed, drove truck for a month, lost brakes going to work, extremely hard pedal; had to use e brake to avoid accident. Found the vacuum pump was bad. Changed vacuum pump, with a known good one, drove another 2 weeks, and hard pedal again; with only 1 good brake application, then no brakes. Took the vacuum manifold out of the picture, ran vacuum hose straight from the pump to the brake booster; no difference.
So, I put a vacuum guage in line. At idle, 22" of vacuum. Apply the brakes, 1 slow application, vacuum drops to zero until brakes released. Vacuum builds back to 22".
I've read where where someone said there should be 25" all the time at idle.
So, I bought a new vacuum pump, with same results as before, 22" at idle, 1 application of brakes, vacuum goes to 0 until brake pedal released.
Now; I'm almost sure it has to be a bad booster, but I'm getting burned out with these brake issues.
Need some suggestions.
Thx in advance.
So, I put a vacuum guage in line. At idle, 22" of vacuum. Apply the brakes, 1 slow application, vacuum drops to zero until brakes released. Vacuum builds back to 22".
I've read where where someone said there should be 25" all the time at idle.
So, I bought a new vacuum pump, with same results as before, 22" at idle, 1 application of brakes, vacuum goes to 0 until brake pedal released.
Now; I'm almost sure it has to be a bad booster, but I'm getting burned out with these brake issues.
Need some suggestions.
Thx in advance.