Attack of the brake grimlins

[puff1]

Help me please! I have a different brake problem. When I clocked my axles I also put in new calipers and rotors in the front. When I went to bleed the system I started having all sorts of problems. I could talk for hours on it all but I'll tell you where I'm at. So far I have put on 3 new master cylinders and two different boosters thinking that was the problem, all in the last few weeks. I thought I must have a leak but I brought it to a shop and the did a proper bleed with a pressure system and they said I have no leaks and no air in the system, they said it was the booster so I changed that last night and have the exact same symptoms. Symtoms are: brakes pressure up solid with engine off (no brake fade) but with engine on the pedle will slowly drop to the floor.

You would think this would be the master but this is my third one all brand new. Bleed everything in sequence, push rod is adjusted correctly, I have vacume or the brakes would be hard and when you disco the vacume with engine running they do get hard and are hard with engine off.

Replaced some lines and have new ss braided flex lines because of lift also put in new rear wheel cylinders and brakes/drums, brakes are adjusted properly. Tested booster check valve the only other thing is that I have weak vacume I don't know how much I should have????? Or its the proportioning valve or the rwabs valve which I bleed properly

Does anyone have any ideas, I know the seal kit for the vacume pump is over 100 bucks I just don't want to change out parts needlessly because my wife is about to make me sell this truck that keeps me away from her The lines to the front calipers look good (no bulges) help, help, help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Tippin Spotted Cow]

Well, I know that if your rears aren't adjusted right, your pedal wont be solid with the truck running until about halfway, down, because you have a split master cylinder, front/back.



Now I know you said you adjusted the rears, but I know the abs deal for the rears can wreak havoc. Putting two and two together, maybe try bypassing the abs sensor and run the line right to the rear end.



Worth a shot, I know a lot of guys pull them off on these trucks because a) theyre worthless and b) you get better rear braking without it.

 

[PToombs]

Aaahhhh! Grasshopper very good pay attention!



My protege is most likely correct. Do away with the rear ABS valve, you have the common symptoms of a junk valve.

 

[puff1]

Thanks guys, sounds like good advice. The connection to the abs sensor is busted and the pig tail is broken too, dodge wants like 160 bucks for both and it sounds like its not worth having. I checked my vacume today and its running a strong 25 inches everywhere. There was one thing maybe you guys could comment on... . I had a guy I know power bleed my brakes he said there was no leaks or air in the system, I know in the books and on all data it says it's a requirement to use a special tool that holds the metering valve open when power bleeding. Do you know why, and what would happen if you didn't. I bet my left nut he didn't do that. Would this cause my symptoms... . any ways thanks alot you two, you always seem to help everyone out

 

[puff1]

Tippen did you ever get your dyno done, and one other thing, I bought a diesel tach from autometer it runs off the alternator, has any one used this type, I have it wired in except the sender because the instructions say to line it up with the alternator laminations which I don't have. Haven't called autometer yet just thought someone might know?

 

[Paychk]

I know in the books and on all data it says it's a requirement to use a special tool that holds the metering valve open when power bleeding. Do you know why, and what would happen if you didn't. I bet my left nut he didn't do that. Would this cause my symptoms... . any ways thanks alot you two, you always seem to help everyone out

What happens is the valve prevents full pressure from reaching the front disk until the rear drums fully seat, then it opens full pressure to the front. Basically when it sees from 3-117 psi , it prevents any thing from reaching the front disc's. So the way around is to manually bleed them, pressure bleed with the metering valve hold off tool, or pressure bleed with less than 3 psi to the master cylinder, not sure how well that will work.



To check the function of the metering valve; watch the stem for movement, while someone applies the brakes.

 

[Tippin Spotted Cow]

Haven't hit up the dyno yet, no. I didn't wanna do it on my stock turbo... which is also now scrap metal. I'm kinda debating what to do about turbos. For the time being I've been driving around my buddy's car. A 1984 Caprice Classic. Yeah... I know... ghetto cruiser...



I have a video on my phone of what my truck does without a working turbo. You've never seen this much smoke. I couldn't drive it like that anymore. It would top out at 60 and take about 5 minutes to get there.

 

[puff1]

What about a cobra stage 4 twin, there on sale now, rock bottom prices only 4600. 00 you would be crazy not to! Or the first half of it the the custom 300 would work nice. My brother likes the Pdr hx40 I just put on his 2002. I'm trying to keep up with you I want my truck to be able to chew up a turbo or two. I just got my gauges in last week I think I run about 600f crusing at 100k (good? bad? i dont know)but it dosn't sound like you cruise. I was going to do a dyno this week but can't get the brakes going yet.

 

[puff1]

About what paychk said, maybe my whole problem is that when I bleed my brakes I pump them up really hard with the engine off. I either stuff somthing between the seat and the pedle and crack the valve. Maybe I should just leave the valve open and slowly pump the brakes with the tube and jar method. I will be so mad at myself if that is the problem. When I pump up the brakes it must be way over 3psi. What about doing the farmer bleed and just cracking the valves over night. The only reason why I been pressuring the system up then cracking the valves is because I want to see the bubbles as they come out, I never have any help, my wife is the Canadian manager for SATA and she's always in germany or somthing. Anyways do you guys think this could be my problem because of the 3-117 psi metering valve??????????

 

[Paychk]

Maybe these would help with solo bleeding:

Speed Bleeder Bleeding Brakes Bleeding Motorcycle Brakes Automotive Bleeder Screw Brake Bleeder

 

[Tippin Spotted Cow]

I'm considering the HX40 from PDR... we'll see i guess.



This might be obvious and a dumb thing to say, but have you checked to make sure you dont have a leak in some obscure place. Sometimes you get a leak, but don't notice too much of a puddle becase it drips onto the frame until you start driving. But then I guess you would notice that you have to fill up the master cylinder often.



Hmm... . I take it you already tried ditching the abs valve, eh?