So I'm trying to figure out what my brake issue is and I believe I've got it down to a failing booster. Calling the brake god @mrblaine
Background:
'97, 4.0, non-ABS
I clipped the left front hard line on the frame while off-road, lost brakes, and got it home and parked it. I swapped out the front lines with 3/16" stainless braided lines. I used one to run out of the distribution block to a tee fitting, then another line to each caliper from the tee. I converted to -3AN at the block and plugged the rear most hole. I used -3AN all the way thru until the banjo fitting at the calipers. I bled the brakes and got it all good... or so I thought.
Problem:
When I hit the brakes it is extremely hard at first, then once I lay into them it softens up. When I release the pedal the calipers stick for about three seconds. The only time I've ever not had this issue was when I got on it and revved it past 4k. After that the brakes operated normally for that stop. I've been able to replicate this.
Thoughts:
I believe the booster has a vacuum leak that isn't allowing the correct differential pressure when at anything under 4k rpm. How should I test this? If the booster is truly the problem, any recommendations on which one to buy or if there is a way to rebuild it (long shot I know)?
Background:
'97, 4.0, non-ABS
I clipped the left front hard line on the frame while off-road, lost brakes, and got it home and parked it. I swapped out the front lines with 3/16" stainless braided lines. I used one to run out of the distribution block to a tee fitting, then another line to each caliper from the tee. I converted to -3AN at the block and plugged the rear most hole. I used -3AN all the way thru until the banjo fitting at the calipers. I bled the brakes and got it all good... or so I thought.
Problem:
When I hit the brakes it is extremely hard at first, then once I lay into them it softens up. When I release the pedal the calipers stick for about three seconds. The only time I've ever not had this issue was when I got on it and revved it past 4k. After that the brakes operated normally for that stop. I've been able to replicate this.
Thoughts:
I believe the booster has a vacuum leak that isn't allowing the correct differential pressure when at anything under 4k rpm. How should I test this? If the booster is truly the problem, any recommendations on which one to buy or if there is a way to rebuild it (long shot I know)?