85b2denver
New Member
- Joined
- Mar 15, 2018
- Messages
- 2
- Reaction score
- 0
- Points
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- Vehicle Year
- 1985
- Make / Model
- Ford
- Transmission
- Manual
First off I have a 1985 Bronco II 2.8l 5 speed with a 4 inch sus lift and 31 inch tires.
So I have been trying to diagnose this problem since i got a new mc/power booster combo wondering if the ones I got are faulty or not. Now, I have bled the system multiple times and im pretty sure there are no leaks, I have also replaced the rear wheel cylinders.
Now if I get in the car with it off, I can pump the brakes and they'll hold pressure. But as soon as I turn on the car, and it's not moving, the pedal drops to the floor immediately with no pressure. Now if i pump the brakes ridiculously fast, I can feel a tiny, but barely, amount of low end pressure build up that disappears as soon as I stop pumping, once again while the car is running but standing still. Me and my dad dont see any leaks, the brake fluid level hasn't dropped at all, and the check valve is working.
Another thing I notice in traffic, is if i have the pedal to the floor and I let up a little bit, the engine revs increase a very small amount. Sign of a bad diaphragm? Or is it normal due to less resistance to the vacuum pressure?
And one last bit of info, when the engine was running, we disconnected the line running to the power booster, the brake pedal was very firm, hopefully showing that the lines dont have air in them.
Edit: I forgot to mention that before I replaced the booster/mc combo due to hissing noises, the brakes felt to be adjusted and grabbing fine, so I don't think that should be an issue
Any help is greatly appreciated!!!!!
So I have been trying to diagnose this problem since i got a new mc/power booster combo wondering if the ones I got are faulty or not. Now, I have bled the system multiple times and im pretty sure there are no leaks, I have also replaced the rear wheel cylinders.
Now if I get in the car with it off, I can pump the brakes and they'll hold pressure. But as soon as I turn on the car, and it's not moving, the pedal drops to the floor immediately with no pressure. Now if i pump the brakes ridiculously fast, I can feel a tiny, but barely, amount of low end pressure build up that disappears as soon as I stop pumping, once again while the car is running but standing still. Me and my dad dont see any leaks, the brake fluid level hasn't dropped at all, and the check valve is working.
Another thing I notice in traffic, is if i have the pedal to the floor and I let up a little bit, the engine revs increase a very small amount. Sign of a bad diaphragm? Or is it normal due to less resistance to the vacuum pressure?
And one last bit of info, when the engine was running, we disconnected the line running to the power booster, the brake pedal was very firm, hopefully showing that the lines dont have air in them.
Edit: I forgot to mention that before I replaced the booster/mc combo due to hissing noises, the brakes felt to be adjusted and grabbing fine, so I don't think that should be an issue
Any help is greatly appreciated!!!!!
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