I'm about ready call it quits and throw in the towel. Nothing has beat me before like this truck and the brakes. All advise will be considered. Brand new master. All brand new stainless steel lines. Brand new pads. Drums in rear are adjusted to where they need to be. The drums seem to feel like they are getting about 30% which is normal with the LSPV all the up, shut. I have bled these brakes starting from the master, rear pass, rear drive, front pass, front drive, LSPV. I have cracked open every y, every joint, every connection. I've taken the master off and re bench bled it. I've bled these things by myself. Help from many. There is no air leak that I can find for the booster. And no fluid leak in reservoir. I can not get brakes on this truck. It takes 5 good pumps to get it to start stopping another 2 to actually safely stop. As if there is a way air is sucked in when I let off the pedal but no fluid leak. And to make it worse after all this pumping one of the fronts almost always sticks and won't let go causing a death wobble but even with it sticking I can push the pedal and absolutely nothing for multiple pumps. Also when bleeding the rear let out a good deal of fluid like you want to see and the fronts will start to bleed desent but I can back the brake line all the way out and it will slowly come to a complete no fluid coming out as if something is in the line. What in the hell is the problem!?

 

Could be a soft line, or more than one, is collapsed internally. They do that when they get old....
Pat☺

 

On brand new all stainless steel brake lines?

 

I know there are flexible lines that feed each caliper. Have to be. You mean each of those are new, with stainless steel braid on them? if so, then never mind.

Nowhere are there any flexible lines that are the old, original ones? If not, then forget I mentioned it. If there are, then what I said stands. Also, the LPSv can glog up with crud from the system. I know you said you flushed it out. Are you sure you got it all? Did you move its bar up and down while you flushed it? That can break loose the crud in it. Just a thought.

BTW: Do you have the pedal properly adjusted? If it's too far one way or anothher, the way it actuates the MC can be incorrect, causing the fluid to get stuck under pressure in the lines.

Good luck to you!
Pat☺

 

Yes, I've replaced all the rubber flex hoses as well to braided stainless. I live in the panhandle and this thing was fully submerged after a hurricane for days. A rust nightmare so when it comes to fixing parts, I have completely replaced the components ect. I flushed the LSPV, I even used a air compressor to blast everything out. Nasty black odd smelling stuff. I didn't move arm during a bleed, but I've moved the arm many times and have bled it many times after that. I read a post about something about the pedal... I'm not sure what I'm looking for in that area tho so you may be on to something. But when I took the new Mc off to bench bleed again, I adjusted the booster pin. It's right at 1/8th of an inch to Mc. Could be closer but that's about as close as I could get it. The pedal thing is a grey area for me.

 

If your booster pin is 1/8” away from contacting the plunger in the master that could be the problem right there. I recently messed around with mine, never felt right, so i got a cheap tool from Amazon for this purpose. It measures the depth to contact the plunger in the master, then translates that to the amount the pin should stick out of the booster. Previous owner’s “mechanic” replaced the booster and master. Could be a mismatch in sone way. I doubt the quality of work of anything that was done to this rig. On my truck for some reason, i find this setup feels best when there is actually some preload to the master. As long as the brakes don’t drag after driving a few miles, it should be ok.

You say you ran out of adjustment. Where? At the pedal, or at the booster pin?

 

I know the tool but I still appreciate it. The distance should not have caused this problem out of no where. The brakes worked fine with the new master installed so the distance of the pin was fine. It's not going to slowly change could it? I just got it closer to the mc which I felt improvement in the pedal movement before the pin reached the mc. It was maybe I'm not sure 3/4 inch play in pedal before yo0u could feel it meet the mc. Now it feels more like 1/4 inch. I don't know how that could be the issue since brakes worked in the past with a further distance. Is it possible the booster can have a air leak? Like a seal or something I can't see inside around the back of this thing because it's shape. And i have no knowledge of boosters and trouble signs.

 

I must have bled this truck 50 times. 40 times by myself which why I didn't spot it sooner. Or didn't hear it sooner. While pumping up the pedal I couldn't be close to each tire to hear anything. But today a buddy helped me. I missed it on passenger rear, thought I heard on driver rear, when I got to pass front I knew. Every pump and release I heard air being drawn in. Regardless of what anyone said I was convinced there is no damn way air can get in system and keep all fluid. I thought the resivor would change. Well it is possible for air in but no fluid leaks. And some people may need to see this, all new brakes lines I installed, I only single flared them to the connect at caliper and drums. thought ah it will be fine. DOUBLE FLARE YOUR BRAKES!!