new member needs brake help

[jeep4fun]

Hello fellow jeepers. This is the first forum I've joined and my first thread. I've read many threads on differing subject in the past and must say that I'm not 100% certain on the rules, but can say that I've solved many of my problems by reading threads. I've joined this forum as I think the other members may be able to help me with my continuing journey of keeping my 73 CJ5 running. Even though it's titled as a 73, it has a boxed frame making it at least a 76 in my eyes. The guy I bought it from wasn't forth coming about what he had done with it. My current problem is stuck front brakes after I had tightened the emergency brake. If anyone out there can help, let me know and I'll post more information of what I did leading up to this issue in hopes that someone may have an idea of what went wrong.

​

 

[elwood blues]

I might be mistaken, but I'm pretty sure that the parking/emergency brake only sets the back brakes

 

[jeep4fun]

That is exactly why I'm baffled. My issue started 4 months ago with what I mistakenly diagnosed as a hot start problem w/ my weber carb. Flash forward after I've replaced cap, rotor, plugs, wires, solenoid, and rebuilt the carb. The key was sticking as I turned the ignition all the way forward and I narrowed it down to the ignition switch. In an attempt to fix that issue I sprayed WD40 up under the dash at the switch. Fixed the sticking, but jeep would crank and crank and never fire; just like it was doing months ago after I'd driven it for a while. It dawned on me that maybe it was the ignition switch the whole time. So I tested. I turned the key to the run position and jumped the solenoid. Sure enough the jeep started right up. I shut it down and tried the key. Crank, crank, crank and nothing. Jumped the solenoid and started right away. I tried this a couple of more times and was pretty certain that the ignition switch was the problem. I'm not skinny or bendy so I pulled the dash as far off as I could so I could get to the ignition switch. Put it all back together and the jeep started everytime I tried it. Problem solved. Time for a drive. Oops! Brake lights are on all the time. Now another problem to work on. After a day or two of tracing wires I finally found a harness up by the ignition switch that must have been pulled loose while I was yanking on the dash. A quick squeeze and the brake light issue was fixed. Now during all this I was doing a lot of leaning on the jeep and decided that I was tired of the e-brake not holding like it should so I cranked on the adjuster nut until it held the jeep. While doing that I pulled the wheels off to check my brakes. Found that the driver side rear had a problem. The self adjuster cable was off track and had gotten wedged in the pad. Fixed that and checked the other side. Put it all back together and started out the garage for a test drive. Jeep won't budge. Ok, I must have screwed up the rear brakes. Took it all apart again and rechecked. Nothing wrong. Back together and this time I can back out of the drive. Until I hit the brake pedal. On the third time of hitting the pedal the pedal is tight and won't move more than 1/2 an inch and I'm locked up again. Threw it in low range and powered my way back into the garage. Jack up the jeep and the rear wheels spin freely. Jack up the front and they're locked up tight. A quick turn of the bleed screws loosened them enough that I was able to push the piston back in to unlock the brakes. I bleed the whole system and took the jeep for another spin. After having to use the brakes about a dozen times, the fronts locked up again. I pulled off the road and sat for a while and was able to get going again with out a problem until I got home and hit the brakes as I was pulling in the garage. That was tonight and I'm at a loss. As you can see from my lengthy explanation, I have an issue that seems to be caused by a serious of seemingly unrelated events. Or, maybe something I did caused the issue.

 

[elwood blues]

I had to double check your intro, so it's a '70 something CJ5 . The front brakes drums also, right?

 

[IOPort51]

That is exactly why I'm baffled. My issue started 4 months ago with what I mistakenly diagnosed as a hot start problem w/ my weber carb. Flash forward after I've replaced cap, rotor, plugs, wires, solenoid, and rebuilt the carb. The key was sticking as I turned the ignition all the way forward and I narrowed it down to the ignition switch. In an attempt to fix that issue I sprayed WD40 up under the dash at the switch. Fixed the sticking, but jeep would crank and crank and never fire; just like it was doing months ago after I'd driven it for a while. It dawned on me that maybe it was the ignition switch the whole time. So I tested. I turned the key to the run position and jumped the solenoid. Sure enough the jeep started right up. I shut it down and tried the key. Crank, crank, crank and nothing. Jumped the solenoid and started right away. I tried this a couple of more times and was pretty certain that the ignition switch was the problem. I'm not skinny or bendy so I pulled the dash as far off as I could so I could get to the ignition switch. Put it all back together and the jeep started everytime I tried it. Problem solved. Time for a drive. Oops! Brake lights are on all the time. Now another problem to work on. After a day or two of tracing wires I finally found a harness up by the ignition switch that must have been pulled loose while I was yanking on the dash. A quick squeeze and the brake light issue was fixed. Now during all this I was doing a lot of leaning on the jeep and decided that I was tired of the e-brake not holding like it should so I cranked on the adjuster nut until it held the jeep. While doing that I pulled the wheels off to check my brakes. Found that the driver side rear had a problem. The self adjuster cable was off track and had gotten wedged in the pad. Fixed that and checked the other side. Put it all back together and started out the garage for a test drive. Jeep won't budge. Ok, I must have screwed up the rear brakes. Took it all apart again and rechecked. Nothing wrong. Back together and this time I can back out of the drive. Until I hit the brake pedal. On the third time of hitting the pedal the pedal is tight and won't move more than 1/2 an inch and I'm locked up again. Threw it in low range and powered my way back into the garage. Jack up the jeep and the rear wheels spin freely. Jack up the front and they're locked up tight. A quick turn of the bleed screws loosened them enough that I was able to push the piston back in to unlock the brakes. I bleed the whole system and took the jeep for another spin. After having to use the brakes about a dozen times, the fronts locked up again. I pulled off the road and sat for a while and was able to get going again with out a problem until I got home and hit the brakes as I was pulling in the garage. That was tonight and I'm at a loss. As you can see from my lengthy explanation, I have an issue that seems to be caused by a serious of seemingly unrelated events. Or, maybe something I did caused the issue.

are these disk or drum in front?? If drum does it have a proportioning valve? If disk have you checked the proportioning valve??
Of course the only way I know to check the proportioning valve is to replace it.
good luck and welcome from the republic of Texas.

 

[jeep4fun]

Hello Elwood Blues and IOPort51. Nice to meet you and thank you for picking up on my post. The front brakes are disc. Front and rear axles are 44 and the rear brakes look like factory jeep but the front appear to be Dodge brakes. At least looking through pictures of various jeep disc brakes on 4WDs web site I can say that they are definitely not jeep. I looked at Ford, Chevy, and Chrysler and Dodge was the closes that I could come to as a match. The jeep ran perfectly for 2 years, then I sat it all last winter while I pulled the tranny so I could replace a clutch. When I got to driving it again it ran great for 3 months and then the starting problem after it had been running started. Never have I had a problem with brakes. So I'm at a loss. Tonight I'm going to loosen the e-brake cable again. It doesn't make sense as they are totally different systems, but I'm at the point of redoing what I've done in an attempt to fix. Although I have suspected the proportioning valve. When I bled the brakes yesterday I did front first, then rear, then front again as every post I'd read said that was the correct way to set the proportioning system w/o the use of a special tool. It certainly feels like the brake system is pressurizing and than not releasing. This morning the brake pedal felt softer, but a few pumps and it stiffened up and I'm certain the brakes are now locked again.

 

[BrockGrimes]

My first thought was proportioning valve.

My second thought is a bad master cylinder.
when the brakes are locked up pull the top off
the master cylinder and check the fluid level.
If it's a dual chamber setup you'll probably see one low and
one completely full.

Pick yourself up some speed bleeders, they sell them at
autozone, they'll be on the isle with all the misc .
They will make bleeding the system easy easy, just stick
a piece of tubing on the bleeder and stick it in a bottle,
open it a little and when you slowly pump the brake it'll
bleed out all the , just keep an eye on the master cylinder,
make sure not to run out of fluid.

 

[IOPort51]

When you have pumped up the brakes and the front wheels are locked, and you open the bleed valves, does the fluid escape with any pressure and do the brakes release? If you bleed pressure from one front wheel do both release?
Ordinarily I disagree with replacing parts until it works but as my father taught me many years ago " a car that stops is worth more than a car that goes fast".
I believe I would start with the master cylinder go to proportioning valve and then wheel cylinders. I think I would get real OCD on this one.
The only other thing I would suggest is use a good quality tube wrench, replacing brake lines is a PITA.
Good luck

 

[Old Dog]

It could be any of the above. I would also make sure it's not a piston locking up, and that the slide is working.
The next time you lockem up try breaking the line at the P.V. to see if there is preasure in the line. If there is get them to lock up again and break the line at the MC to check for pressure. This way you can tell where its holding the pressure back at.

 

[IOPort51]

It could be any of the above. I would also make sure it's not a piston locking up, and that the slide is working.
The next time you lockem up try breaking the line at the P.V. to see if there is preasure in the line. If there is get them to lock up again and break the line at the MC to check for pressure. This way you can tell where its holding the pressure back at.

This is what you need to do, exactly.
But be sure you have good tube wrenches when you start.

The most intelligent thing accomplished in this thread is to abbreviate Proportioning valve. Dog, once again you have my admiration, for what that is worth.

 

[Old Dog]

The most intelligent thing accomplished in this thread is to abbreviate Proportioning valve. Dog, once again you have my admiration, for what that is worth.

My spelling is for so I abbreviate when ever possable.

 

[LongHorn]

My father taught me many years ago " a car that stops is worth more than a car that goes fast".

X2 on that! Way to go IOPort51.
​

 

[jeep4fun]

I'm starting to think the PV is the culprit as well. I didn't have time to do all the opening and closing of valves as my 20mo was crying and the wife was shooting me the "you better get your *** in here and stop fV@king w/ that jeep" look. I did get a chance to jack the front end up and the wheels spun freely. I took my hand and pumped the brakes and they locked up again. I jacked the back just to check for sanity sake and they spun. My understanding is that the PV regulates the pressure so that more power is applied to the front. If the PV has gone rogue than maybe its just sending too much power to the fronts? What actually causes brakes to release after pressure has built? I guess what I'm asking is when I hit the brake; the fluid push the pads, but what happens when I let up?

 

[BrockGrimes]

Well it usually flows back the the master cylinder.
But like i said if you have a two chamber master cylinder,
if it's locked up pop the top off and see if one chamber is low and
another high, you'll get the same indication with a bad P.V. or a bad MC.

 

[IOPort51]

I like the Dogs idea, all you need to do is break the fitting at the front wheel line of the master cylinder and if it is still locked it pretty much has to be the PV.
PV's are not serviceable and they are a bit pricey and I really do hate to replace parts until I stumble upon what is wrong,

 

[jeep4fun]

SOLVED! Thank you all so much for your help. Your ideas helped me diagnosis the issue. Turns out it was the ignition switch! My new ignition switch is longer than my old and was hitting the top of the brake pedal not letting it come all the way forward. I noticed that the brake seemed lower than the clutch pedal and began looking around under the dash and found the issued. I believe the brake rod running into the MC was not being allowed to fully return causing the release valve in the MC not to open. A quick few cuts w/ my dremel and all was good.

 

[BrockGrimes]

lol thats a new one.

 

[IOPort51]

don't I feel like a dumb a** !!
That is totally off the wall!!
once again, when you have a problem the first thing to do is to look for what has changed.

 

[JSnow]

nice find, I had a similar issue, replaced my MC and it sat further through the firewall than the old one so the rod never let it fully release. had to cut the rod shorter...hopefully the next time I replace it, I don't have to figure out how to lengthen it

 

[Old Dog]

Thats great you found it.
I have to remember that one.