Phantom brake problem, read and get stumped

If you help me fix this, I will buy you a month on TRS!!


Ok, my brakes have some issues that I haven’t been able to figure out.

From the begging.

Started a year or so ago. The setup at the time was dana 35 calipers with slightly longer soft lines and 2 ½ inches of lift. No back brakes with master plugged at back brake port. At times I would loss the brakes. 3 years before this running the same setup it was fine. Quick pumping of the peddle would get them back. Things I checked where air in the system, loss wheel bearings, and the soft lines. All ok. So I ran it as it was ok.

Then I redid the lift and front end. 4+ inch custom flexy lift. Extended soft lines. At first the brakes worked great. But then it started to exhibit the some symptoms as before. After turning I would loss brakes. Peddle would go to the floor. After a few quick pumps I would get them back. Same things checked again, air, wheel bearings, soft lines and hard lines, all ok.

Then I did the 44 knuckle swap. Brakes worked great for the first few months as they where bigger. But then one wheelin trip this fall it started doing the same thing but really bad. After turning I would loss brakes and couldn’t really get them back. Things done trying to fix it. Swapping in two other master I had and then finally getting a new one. Didn’t help at all. Extended steel braided soft lines, did nothing to help. The only way I can get the brakes or brake to work is one hard line right to the driver side soft line. With this configuration I can run one front brake and it works fine.

For the front one hard line to a tee, off the tee the driver side soft line then a hard line over to the pass side soft line.

Now the really weird thing. After getting a peddle I move the truck and turn peddle goes to the floor. I pump the peddle get one back. Then with the truck just sitting fluid flows back to the master as something is pushing fluid back through the system. Both calipers are good. Swapped them from side to side, swapped other calipers on, but still the same thing. As soon as the pass side is connected all the gayness happens. The only other thing I haven’t tested by putting a different one on or replacing is the hard line form the tee to the passenger soft line. And it isn’t leaking anywhere. And I find it hard to believe that a hard line could expand and push back as much fluid as there is coming back to the master. And again the hard line does not move when the wheels are turned and that is the key factor to the problem. The wheels need to be turned in order to loss the brakes.

And don’t tell me to bleed the brakes trust me that’s not the problem. I have literally run a gallon or so of brake fluid through the system trying to fix this damn thing. Also the wheel bearings are tight. And as for the wheel wobbling or anything like that all the ball joints, tie-rod ends are all new. At any speed if the wheel is turned I loss brakes.

HELP, I DON’T KNOW WHAT THE HELL TO DO NEXT!!!!!!!!!!!!!!!!!!!!!

With the rear brake port plugged permanently, are you bottoming the double-plunger in the master cylinder?

It was not designed to be used in this manner. The same hydraulic pressure that is supposed to actuate the rear brakes can push the normally-centered plunger to the front.

Is there any particular reason you aren't using the rear brakes? It really will stop better that way....

Hydraulic pressure has to go SOMEwhere. Where is the rear going, if it is blocked? I presume you have a permanently-on BRAKE light. If you don't, you probably should.

Yes it will help stop better, but I dont have them set up and on tht trail Im fine with just front.

As for the rear port it worked fine for 3 years running it the same way Im trying now. Also tryed running the rear port to the passenger side front but it didnt help. Ran the rear port to the driver side front and it worked ok while at the same time having the front port running to the passenger front but nothing.

The main problem is the front right. Tryed all sorts of configs but every time the damn pass side front makes everything FUBAR.

Once again it works ok untill the wheel is turned in either direction.

i had a similar problem a while back, not on a ranger, but on a volvo, we wnet through and replaced everything, master, all lines, calipers, proprtioning valves the whole nine yards, in the end we finall discovered that the brake booster was on its way out causing the exact same symptons you are encountering, since its the only thing left u havent toyed with id say try that, other then that everything sounds like it should be functioning

I agree with the booster.

You may be able to fiddle with the adjustment a bit. The pin comming out from the booster is adjustable. It can be screwed in or out. If it was played/tampered with at any time or not locked down it could work itself out of adjustment. I have a booster in the shop I could get a measurement of how much pin is sticking out, if you want to check it.

Changing out the masters rules out blow by on the masters piston

James, I don't see how a booster can work for a few months after changing a line and then stop working. That says this has to be hydraulic, somehow, right?

I would submit that blow-by past the piston might be (temporarily) fixed by replacing the master, but the excessive pressure from the plugged port would blow the new one, eventually. That is, it's repairing the symptom instead of the problem, and the symptom is coming back as a result, but it takes a while.

And I really don't see how a misadjusted booster can force fluid back into the master cylinder.

Is the rear setup at all for brakes? Did you totally remove all the brakes? If not, i would run the rear brakes. Also, how good of shape is your proportioning valve? I have no experience with them going bad so I don't have any idea of the symptoms it would cause, but i would try and switch it out for a different one. If you have replaced everything else, if im correct, the only things that you haven't replaced would be the proportioning valve and your still without any rear brakes. I think i would try the proportioning valve first, then the rear brakes. You've done everything else, it has to be one of the two.

MAKG said:

I would submit that blow-by past the piston might be (temporarily) fixed by replacing the master, but the excessive pressure from the plugged port would blow the new one, eventually.

Click to expand...

Bingo.

on my buddies s10 it did the same thing on turns found that one of the banjo bolts was snug but not tight and was leaking ever so slightly... just a dumb thought

I had a similar issue a few months back on my b2. I couldn't find a leak anywhere in the system but the damn brakes wouldn't work. Bled them fine but just couldn't get any pedal. Replaced the booster and all problems were solved.

Well just got back from the shop. Wasn’t planning on really working on the rig, just installing a Mag-light clamp kit it got for x-mas then I got to thinking.

Disconnected the brake booster and drove it around the yard and this helped me determine that only right hand turn to lock made the peddle go to the floor. As I was able to get a peddle back faster without the booster hooked up.

Put her up on stands AGAIN and turned the wheels and noticed that a full lock right turn made fluid come back into the master. Looked really closely at the pass side and noticed that the caliper was making contact with the damn TTB beam. Seems that the right beam got tweaked and was pushing the piston back into the caliper on a right turn. Heated her up and bashed it back to match the driver side that was not messed up. And guess what, the damn brakes work now!!!!!!!!!!!

I swear whenever I get to the point where I cant figure something out I ask the question here on TRS and a new hours or mins later after posting I figure it out by myself.

hmmm, well thats rather a bit on the ineresting side

Ya, I know. Only took me a year to get it worked out. Going to cut out the old part of the beam and rework it with some 3/8". She must have been bending for some time both ways as the problem seemed to come and go.

So who gets the membership? Your already a premium...lol

I'm reading through your 1st post, and the fact you said it was happening after turning couldn't scream any louder "Caliper hitting something!!!"

I had this on my Ranger after putting the D44 in, the calipers hit the shocks when I turned, causing exactly the same thing.

I see you managed to figure it out though.

BTW, I would hook those back brakes up, if something in the driveline were to break while climbing up a steep hill (driveshaft, t-case, front axleshaft, etc.), you'll basically be free-rolling backward down that hill out of control.