Full Size Jeep Network

So to make a long story short, I had my rear shoes and drums replaced a while back. After a couple drives I started smelling a new strange smell. Almost electrical, but not exactly. The smell seemed to originate in the the passenger side rear wheel well. Upon further inspection, when I put my hand on that wheel, it was pretty stinking hot, while the driver's side rear was nice and cool.

So fast forward about a week, the Jeep went into the shop (different one) to replace the bent rear axle shafts. While they were in there, I had them take a look at that brake drum. They said it would not even turn by hand. That drum was way too tight. So they of course loosened it to where it should be and I was on my way.

After another couple of drives I was experiencing the same smell and heat from that one drum.

Anyone know what could cause this one drum to continue to over tighten itself? I need to just open the up and see what I can see. The old hardware was used when the drum and shoe were replaced.

The only thing I can think is that either the wheel cylinder is sticking, or maybe something was not put back in quite right. Thought about just getting a new set of hardware and taking them all back apart and installing the new hardware.

Any thoughts?

Typically, drums should only ever self tighten in reverse. If you have a brake spoon, you can loosen the self adjuster, and see if it frees up. If it doesn't, then maybe the wheel cylinder is sticking.

I have never seen if this is possible, but maybe the self adjuster hardware was put in backwards, making it tighten when going forwards? I can't think off hand how this could happen, but worth a check I suppose.

Maybe also check to see if the brake shoes are not mixed up. I once put 2 forward-facing shoes on one side of a rear end and put the 2 shoes that are supposed to be rear-facing on the other side. I didn't even get so far as driving it because I could barely get one of the drums on. A friend clued me in that I'd mixed up the shoes.

Your brake self-adjusters are apparently working, but not working correctly. You will need to pull that drum and verify that the parts were reinstalled correctly, and that there are no damaged parts. The self adjusters have left and right threads, and the pawl that moves the starwheel has a left and
right stamping. If someone switched the parts from one side of the vehicle to the other, or installed the parts backwards, you could get results like you describe. It could also be that someone replaced a damaged part with one that was not the correct replacement, and that would explain why you do not
have the same problem on both rear drums. I do not remember what side of the vehicle gets the left hand thread self adjuster, but you should have
one of each (right and left) on your rear drums. Out of curiosity, is the side that is working actually holding the correct adjustment, or is it getting looser
all the time? (and you just haven't noticed yet)

I believe that the driver's side seems to be fine.

After pulling the drums off and inspecting everything, all the old hardware was re-used. Which I would expect should be fine. Although the self adjuster wheels on both sides look like the teeth may be a little worn.

The only thing that I noticed on the passenger side (one that was over-tightening) was that the self adjusting lever was not really in contact with the self adjuster teeth. So i pressed on the lever ect. to get it to touch, but it seems as if it is hit or miss with catching the teeth when I spin the self adjuster.

I went ahead and ordered all new hardware for the drums. Plan to just break them all down and rebuild with the new parts and see what happens.

Also, my access holes in the backing plates seems to be almost welded shut with a plug, although you can clearly see there are ports. Is there any way to get these opened up? I tried a hammer and a punch from both sides, and that seemed to not even budge them.

I took some pics for you guys to look at:

Driver's side:


Passenger side:


Access holes:

I perceive the adjuster is inside the shoe on the driver side and outside it on the passenger.

Is that the way it supposed to be?

The thing is I'd say the passenger side seems correct to me. I guess I'll have to get out the manual. Dunno if the '84 is the same as yours.

I wonder if the arm not being in contact with the adjuster would allow the adjuster to turn on its own. Nothing looks overly wrong otherwise.

Stuka wrote:I wonder if the arm not being in contact with the adjuster would allow the adjuster to turn on its own. Nothing looks overly wrong otherwise.

Yes, that is what I think it is doing.

Parts will be here today to make everything all new again. So hoping that just having new parts on it will cure this evil!

But I am glad I am working on it, in that I saw that one of my exhaust hangers has decided it has had enough lifting for its life and has broken. Causing my exhaust sag and rely on just one hanger. So out will come the bailing wire. Was already planning to have an exhaust shop fab up a new exhaust for me, so I guess this will just push that project up a little sooner. Want to get a new muffler that will tuck up more and not be as exposed as the current one is. Also not near as big. I think I am going to also have them fab up a new Y-pipe as well.

The shoe with the longer liner is the secondary and should be in the rear position. Looks correct to me.

You can see in the picher that the passenger side has the left hand threads on the adjuster which is correct.

I don't think lack of contact between the pawl and star wheel would cause it to tighten. The pawl is a ratchet and is there to tighten/keep it from loosening. It would be fighting the spring to self tighten.

There should be a spring between the back of the shoe and the upper end of the pawl that pushes it radially inward. It's on the outer side of the shoe on my Dodge. Can't tell from your pics. Is it in place?

Is that a shadow that makes me think the driver side pawl is behind the shoe?

SJTD wrote:The shoe with the longer liner is the secondary and should be in the rear position. Looks correct to me.

You can see in the picher that the passenger side has the left hand threads on the adjuster which is correct.

I don't think lack of contact between the pawl and star wheel would cause it to tighten. The pawl is a ratchet and is there to tighten/keep it from loosening. It would be fighting the spring to self tighten.

There should be a spring between the back of the shoe and the upper end of the pawl that pushes it radially inward. It's on the outer side of the shoe on my Dodge. Can't tell from your pics. Is it in place?

Yes, this is in place.

SJTD wrote:Is that a shadow that makes me think the driver side pawl is behind the shoe?

That is indeed a shadow. Both pawls are outside the shoes, in the correct positions.

I guess my last question then is how do the self adjuster operate on our rigs? Is it through reversing, or somehow controlled through the parking brake engagement/disengagement?

I know my parking brake hard line is snug with the addition of the lift springs, but the actual cable is setup fine in that I am getting good engagement near the bottom of the stroke on the actual parking brake.

Last but not least, I have a different looking shoe for each side. Driver on the left. I assume this is correct?



Thanks for all your help.

Looks like one was balanced, and the other was not?

Maybe so, but the passenger side has a discernible indention compared to the driver's side. Any thoughts on that? When I have looked them up online it seems some have this and some don't. But no indication that driver and passenger are any different from one another.

It's likely they were just cast at different times/from different manufacturers. One likely NEEDED to be balanced (ie: poor casting), while the other may not have. Or they may have simply cheaped out and not balanced it. AFAIK there is no difference in drums side to side. A drum is a drum.


aa

Think I might have found the problem....



If I just replace this one wheel cylinder, do I need to bleed all four lines, or just this one?


Sent from my iPhone using Tapatalk

The parking brake is not involved in the adjustment.

The adjuster operates when backing and applying the brakes. If they are loose enough the pawl will catch a new tooth on the star wheel. My understanding is that the adjustment actually occurs when the brakes are released. If they aren't loose enough the pawl won't move enough to catch a new tooth so they normally won't overtighten.

I don't know it the brake cable being too tight will cause the adjuster to malfunction and overtighten.

Certainly a problem, is the piston sticking/not being pushed back in by the springs?

You can bleed just that cylinder.

Got the cylinder changed out and bled the brakes. Went for a short drive tonight to get some gas then the long way home. Both drums seem to be about equally warm, so maybe that was the culprit. Will drive it to work tomorrow which means a nice dose of traffic and about 30 minutes+ drive time. We will see if I smell brakes when I get to work.

Every other time the actual wheel is warm/hot to the touch and this time is was not. But I am keeping all fingers crossed. The old girl has fooled me once or twice before. I actually have a nice new chirping sound coming from that wheel now as well. Just had the rear axle shafts replaced with the Dutchman ones from BJs. Shop did all the bearings etc. They are a reputable driveline shop, so I am fairly confident they got it right. But the chirp concerns me a bit.

A couple of thoughts: In the pic for the left brake, it looks to me like the star wheel spring is installed wrong. Look at the angle of the spring in this pic (arrow) and compare it to the passenger side. I think the spring is upside down, with the spring in the teeth of the star wheel. This will prevent proper adjustment of that side but will not cause the problem you are experiencing.
I have circled 2 bends on the shoes, there are 3 on each shoe, on both sided of the shoe. They rest on raised pads on the backing plate. They tend to wear grooves in the backing plate and then the shoe sticks in those grooves. Check to see if those pads are worn, if they are, weld them up and then grind them flat again.

Thanks Curly.

On the passenger side yesterday I went ahead and wire brushed off everything to get down to the contact points and put a light amount of anti-seize on them. Plan on doing the same to the driver's side this weekend when I swap out all the hardware on both sides for the new stuff.

Drive to work this morning seemed to be the same experience as last night. Both drums seem to be about the same, and no more smell of burnt brakes from the passenger side. (Still keeping fingers crossed)

1979bettywhite wrote:...I actually have a nice new chirping sound coming from that wheel now as well. Just had the rear axle shafts replaced with the Dutchman ones from BJs. Shop did all the bearings etc. They are a reputable driveline shop, so I am fairly confident they got it right. But the chirp concerns me a bit.

If you got the brakes hot enough, it's entirely possible you cooked the seals and/or bearings. Might be worth pulling the shaft and checking everything over. If you're using grease on the bearings, repack them, if diff oil, may be time to flush that.


aa