Brakes pull to the right!

Hello!

Well, when I bought this Jeep the brakes pulled to the left...it was scary! I replaced the wheel cylinders, brake lines and pads on all four wheels. Now it pulls slightly to the right. It doesn't seem to have this problem all the time...but usually after extended use it seems to get worse (or maybe I just get tired of correcting the wheel when I stop). Since everything has been replaced...I am at a bit of a loss. I have adjusted and readjusted these brakes ---but they still pull a bit.

I was doing some reading and saw a post where a recommendation was made to bypass the proportion valve using some T fittings. My theory is that the valve isn't working so well anymore...instead of hunting down a new proportion valve it would seem so easy to just to bypass things with some T fittings.

Does this sound like a good plan or a plan for disaster? :? Also, after inspecting the lines going into the valve I worry about breaking the lines trying to get them disconnected. Any advice on a safe way to do this w/o wrenching them off?:?

Thanks,
Nathan

1974 DJ5C (2wd)
10" drum brakes all the way around
33x12.5 tires

 

Nathan, the prop valve is between the front and rear brakes, so it won't make the Jeep pull left to right. Not sure a '74 Cj has a prop valve - pretty sure a '75 does, and a '73 does not. The DJ might be the same, or it might not have a prop valve at all.

I presume that the 10" drum brakes on the DJ are the same as the brakes on the earlier CJs. Those have self-adjusters, and you should not need to adjust them when you put them together. They will automatically adjust when you back up and brake.

Take a look at this thread http://www.earlycj5.com/forums/showthread.php?t=50401 and see if it makes sense to you. IIRC the 10" brakes don't have cables, instead rods, but the principle is the same.

 

don't know if its safe or not but the only way I've ever succesfully gotten bad lines off is drenching it in pb blaster then burning it out with a propane torch. a couple times and it will come off. again I don't know how safe this is for you or your brakes but I've never had a problem and do it all the time.

Its best to just replace them though, they're cheap.

 

Thanks for the link...I'm going to go over my brakes again and make sure that the self adjusters are working properly.

On the DJ5 the "Brake Warning Valve" sits just in front of the master cylinder. I went back and looked at the FSM for the DJ and here is what it says:

"When a significant pressure differential occurs between the front and rear brake systems, the piston will shuttle toward the side with the low pressure."

So, I guess I just need to go back through things again...I have manually adjusted the star wheels but things don't stay adjusted very long. Perhaps the self-adjusting mechanism needs some work/replacement.

If anyone else is struggling with brakes on their DJ5C and doesn't have the FSM here is a link to check out:

http://www.postaljeep.net/DJ5Cbrakes.htm

 

Oh, re the lines, a flare nut wrench is required. Supposedly the Snap-on wrenches are the only brand that won't bend, but I've never bent my Craftsman line wrenches.

 

Also, does anyone have a good source for 10" brake parts?

 

Yeah, that's not a prop valve - that's just a brass block with a passage through the middle and a switch to detect master cylinder failure. A prop valve will modulate the rear brake fluid pressure to prevent lockup http://www.wilwood.com/Products/006-MasterCylinders/001-PV/index.asp

I suggest you ask about the 10" brake parts on the "early" forum, since those CJs use the 10" brakes.

 

Thanks for sending me in the right direction

 

My 74 had a factory prop valve on it. When I was having trouble and went trough and did everything, scrapping the prop helped. I am all drum but I think they started added then regardless late 74.

 

Thanks for the input...Well, unless someone added a proportion valve it doesn't seem to be standard on the DJ. I'm going to take another look in the light tomorrow...I'm also going to take a look at my setup compared to the FSM.

I've got to admit that I haven't spent enough time going through it. There are great troubleshooting sections that I should check out...starting with easiest and cheapest first!

 

I may have missed it, but when you listed the parts you've replaced, you don't list turning/new drums. Drums are a lot more persnickity than discs. Most folks have never had the experience of dealing with drums. I've had a few vehicles where the adjustment was manual, no adjusters.

Reason I asked was I seem to remember glazing, contamination of all sorts would make drums grabby, kinda like my second wife.

 

Yeah the drums haven't been resurfaced...they looked ok...I thought.

I'm going to take everything apart in the morning and have a look...

 

The drums are your problem. Have them turned or replace them. They are really not that expensive...If something has 35 year old drums on it...I will normally replace them when I do a rebuild...A world of difference.

 

Ok...today I checked out my brakes...and just about broke my back wrestling with those 33's! They are heavy!

Well, first I realized that self adjuster wasn't installed correctly on the right side...oops! It is probably a good time to replace the springs and self-adjuster parts - the star wheel is has some points missing...these are cheap variables that I can eliminate.

Surprisingly, the drums look great. No pitting and/or scarring.

I am a bit concerned with the backing plates...these contact points (the red circled ones) are very worn. I am not sure what affect they have on the overall mechanism...



Also, while the tire was off I realized that the king pins are pretty loose. I could move the drum up and down.

Here are my conclusions:

1. The self adjuster parts need to be overhauled.
2. The worn contact points on the backing plate aren't helping anything.
3. The loose kingpins, I think, could affect breaking. They need to be repaired.

So, now I've got to hunt down some parts and continue...I am beginning to think that working on Jeeps is a bit like searching for the perfect wave...

 

How's your ride? Does it roll from side to side? I have a 72 with flat springs and it feels like it's going to tip over just from me climbing in. I don't think that would contribute to any kind of brake problem, but them is one of the first things I'm going to do. I've only had it a month or so.

Does anyone still have their brake shoes arched? Maybe that'll help.

 

No this DJ doesn't roll at all...the suspension is pretty tight...

 

No problem - just keep at it and you'll get it back together. I think you'll find that working on any 30 year old car will have its frustrating moments.

Re 1) the adjusters, yeah you'll need to clean them and put them together properly.

Re 2) I've seen that before - those spots are supposed to be greased, but either they never are or the shoes wear into the backing plates anyway. At worst, you'll need to replace the backing plates. Might work ok as it is; if not, the brakes won't adjust right.

3) Won't affect the braking, but it will make the DJ wander and really chew up your front tires. You have to fix them, unless you can afford new tires every 5000 miles.

 

I would like to reiterate that you should at least have the brake drums turned (regardless of how good the look). If you do not...that is fine, but if it still pulls after everything you have done this time around, then it should be your next step before you look at anything else.

 

Thanks for the input.

Yeah the kingpins are on the list to replace. I am a bit intimidated by them...the FSM says the new bushings need to be reamed...I am a bit worried about getting everything taken apart and then not being able to get it back together...R)

Those contact points are pretty worn...I'd like to just replace the backing plates...and while I'm at move the front two brakes up to 11". Seems a lot easier to get parts. I guess the trick will be finding new backing plates. A quick look on ebay revealed a set of four 11" backing plates for $200. A bit steep...

Yeah turning the drums makes sense...its a pretty low cost easy thing to do.

I guess I've got some decisions to make

 

just curious
has anyone else seen wheel cylinders mounted on that angle before ?
I don't think I ever have...maybe I've been sheltered
how would you get the air out of those wheels cylinders with them mounted on that angle ?
have the backing plates been rotated or redrilled ?