No Stopping Here!

I've been fighting a brake issue for the past week or so. My 46 cj2a sat for about a 4 days and I went out to take it for a drive. The brake pedal was hard as a rock when I got about 1/2 way down. Thought it was the M/C (oh I converted to Herm's dual reservoir) ...but I guess it wasn't solution because the same problem persists. So I went through and bench bled the master again. Got a few bubbles out of the system. Then again went through the bleeding process starting at the rear passenger wheel cylinder, then rear driver side, then passenger front, then lastly the driver front. No air in the lines, yet still the pedal feels rock solid when it gets half way to the floor. Here is where I'm lost.

...So when I'm at the wheel cylinders in the back and my girlfriend is manning the pedal she pushes it and it goes about half way and that is where it becomes extremely hard. When I release the bleeder screws in the back, the pedal will go to the floor as fluid fills my bottle at the wheel cylinder. this repeats over and over and never stops. It doesn't change and the pedal is hard at the halfway point. So with no air in the lines I continued to the front.

At the front, the pedal still goes half way and is rock solid...I turn the bleeder screw and fluid comes out but for some reason the pedal does not drop to the floor like it did in the back. Repeated this over and over and nothing changed (all air is out of the lines by the way) So here is what I did next...

I went to the back passenger side wheel. I turned the star wheel all the way out so the shoes are in almost all the way (as far from the drum as possible). Now the pedal goes all the way to the floor...unfortunately there is no pedal pressure. I then went back and tightened star wheels up all around...this did nothing, now the pedal just goes to the floor again. for the heck of it I took it for a drive in the neighborhood and only get the slightest braking power. If I pump it up like mad I get a little resistance in the pedal and it will slow down but there is really not consistency or confidence in them working properly.

Does anyone think that I may have something wrong inside one of the brakes. I remember a spring broke in one of my drums a couple of years back but I don't quite recall the symptoms being the same. Has anyone had a spring give out or wheel cylinder go bad and have similar issues like this? Hydraulic brakes are so simple yet this issue is driving me nuts! Thanks again

 

Doyou have any binding in your linkage? Do you have binding in your wheel cylinders or shoes? You may have to take off your rear drums. If its stock you're going to need a hub puller. Do you still have the slit for the feeler gauge in the drums? I see you mentioned a star adjuster in the rear....thats not stock for 1946.

 

So the brakes were working fine until the jeep set for 4 days. After 4 days the pedal locks half way down. Is this correct???

 

Sounds exactly like what happened to my cj2a. After checking everything it was a stupid easy and cheap fix for mine. I checked everything bled couple times disassembled mc and everything just tto find my hydraulic brake switch failed. The internal guts of the switch fell apart and plugged the line solid.

My symptoms were pedal hard as a rock won't go down far enough. Brakes not applied and will not apply no matter how hard I pressed pedal. I tried opening bleed screw and then I could move the pedal but once I bled again problem was back

Basically this symptom means plugged line

 

And for me this happened suddenly. Drove to work fine no problems got to leave for lunch and pedal won't depress hard as a rock

 

Thanks everybody! I'm going to go work on it (sorry on Hawaii time so I'm a few hours behind everyone.) I do have cj5 11" brake on it as well as Herms dual m/c kit. It did sit for about 4 days. I also replaced the rear soft hose, the old one wouldn't pass compressed air even, replaced that as well as one wheel cylinder in the back. So the front soft lines might be swollen and clogged too causing the problem? I'll pull it apart shortly and maybe check the front wheel cylinders...what has me boggled is that when I bleed the front I still get a little fluid out of the bleeders...but again the pedal only goes down part way unlike when bleeding the back, the pedal dropped to the floor upon opening the screw.

 

I don't think it could be my brake switch since I have it plumbed off of a T.

 

My switch was also plumbed with a tee and the rubber inside the switch and plugged the tee. Solution was to remove the tee and grab and pull out the rubber plug that was now there that was literally 3/8" measure with a ruler. Being as easy as it is to unscrew the brake switch. I would suggest un-screwing to check it. It's easier than checking failed rubber flex lines but if it's anything like your rear hose I'd suggest replacing the front too for safety. The ones for my cj2a were only 15 bucks each but I don't know the price on your application.

 

I actually found a picture of my failed brake switch plugging the tee as you can see in the picture it was pretty bad and being in a tee didn't make it better.

 

Wow! I'm going to have to pull that switch out and see! I just pulled my two front drums and things look ok in there. The wheel cylinders are dry but I only see fluid pushing one piston out one of the cylinders. Maybe this could be part of the issue. I'm going to replace it but since fluid is passing though the fronts when I bleed I guess I will go to the back passenger side if I don't see any issues with the brake switch. Oh these are 11" drums I swapped in. They worked great until last week! Thanks guys, going back out in the garage for another hour or two to figure this thing out. I'll post back.

 

Funny that I pulled the switch and doesn't look like there is anything wrong with it. Went through all my brakes, wheel cylinders, all the brake hardware and everything is fine. I go to bleed it and get a better feel in the pedal than the last few times (I also ran compressed air through all the lines from the wheel cylinders to the MC and there were no restrictions before re-bleeding everything) Still doesn't feel right and now my brake lights switch is not triggering. I have the same pressure switch. Did you bleed the line going to it? Also since I have a large and small reservoir I have always had the large one to the back brakes and the small one to the fronts. Maybe I will go back and switch those up.

 

The bigger reservoir of the two on a dual MC is usually for the front brakes. Most of your stopping power is needed in the front brakes, so greater fluid pressure needs to go there. But I'm not familiar with Herm's setup.

 

I would replace the flexible line at the front too. I had a car with similar braking issues, but when it got rock hard, it would also pull slightly to the right. I replaced the flex lines and all braking problems were solved. It seems fluid gets between the inner liner and the outer casing and, when pressurized by the pedal, it closes off the inner liner. This makes the rock hard pedal because the wheel cylinder never gets the pressure.
-Donny