Rear brake woes....... one drum hotter

Hi guys,
Yesterday, a friend and I replaced the rear main line, both rear wheel lines, both wheel cylinders and bled with dot 4. I was doing a test run and everything seemed ok until I got up to about 45-50, hit the brake lightly to drop about 5-10mph...........then it started wobbling/vibrating pretty bad. It stopped when I slowed down and turned onto a side road, so I thought maybe things were just settling(deep down I figured there was a problem though).

Drove home, and same thing happened on the highway about 2 or 3 more times. When I got home the rear driver side drum was smoking from the back, and was a LOT hotter than the passenger side. I figured it was a cheap wheel cylinder, so I put a new set on. This was after seeing the shoes respond with the drum off.....the pad wasn't retracting when I let off the pedal.

With new cylinders on now, I've only experienced the vibration about 1 time over about 10 miles of driving. The thing is though............THE OTHER drum is the one running really hot now!! It's not smoking, but it's definitely running about 2 to 3 times hotter than the driver's side.

After some research, I'm thinking it's maybe a warped drum. The thing is though, before we replaced the lines and cylinders, it never did this. Could the new parts be too much for the old drums or?? Anyone have an idea? Please post if you can help.................Thanks!

Edit: new springs and pads were added too, and it's a 96 with ABS, dana 35 9" brakes

Take your drums in to have them checked.. Did you adjust your brakes when you put new cylinders? Did you change sides that the drums where on?

Did you replace the hardware such as springs that retract the shoes? I had a problem with one of my rigs where a groove was worn into the backing plate, the shoe hung up enough to problems. You need to fix it obviously, the heat will destroy seals,boil brake fluid and cause drum cracks if hot enough.

Thanks for the replies, sorry 4 the delay, but I went to sleep about an hour after posting. Anyway, the drums were not swapped, they are each from the same side that they originally came off of, and yes I adjusted the brakes after putting everything back together (with new springs).

Biggest mystery in my mind is how at first it was one side, then after replacing the cylinders (again), the problem went to the other side. It's my DD, so I'll probably have to wait til the weekend to pull the drums and get them checked/turned unless I find a place with evening hours.

I'm just really at a loss as far as knowing whats causing it, so i figured I'd ask and get as many ideas as I could.

Another thought is the e-brake....would there have been any way it got out of whack considering everything else I replaced?

Stupid question double check your adjusters there are a right and left you do know that right?

Jeepm@n said:

Stupid question double check your adjusters there are a right and left you do know that right?

Click to expand...

Yep I was actually getting ready to post an update. Pulled both drums again and reset the adjusters. I used a method I saw on a site about pulling the e-brake several times to adjust rather than the back up and stop method. "seems" to have worked for the moment since I test drove it and had great braking and neither drum was significantly hotter than the other. I guess time will tell. I got done right as the heavy rains were starting again, so I'm not gonna be messing around with it anymore at the moment or prob. even this evening.

Thanks for all the help, I'm hoping it was just poor adjustment.........I'll bump the thread if anything goes crazy from here on out............

Well looks like I spoke too soon! I didn't have much chance to mess around during the week with all the rain and going back and forth to work, but the problem has returned!

All we did last weekend was replaced line to the back plus each line to the wheels, replaced wheel cylinders and put in DOT4 instead of 3 while bleeding it.

Symptoms: vibrations anywhere from 30-50mph, most times associated with braking then releasing, sometimes doesn't seem related to braking. Also, one drum WAY hotter and smells like brake pad burning.

All I can think of is warped drums, but don't understand how that would show up after what we did..............unless old drums couldn't handle pressure of new cylinders or??

Any other help, I'm getting desperate, and hate to just buy new drums if that might not even be it.

Hi guys......... Update time. Everything was going OK until the last week or so. I think it was set off again by backing up and braking (not fast, just not being as gentle as I have been). Anyway, so l'm going down the highway about 65 and as I decelerate, it starts shaking to beat HELL at about 55..........stayed that way going down to 40 or so. Got out and checked it and sure enough, the driver rear drum is extremely HOT.

I don't know WTF is going on with this thing, but I'm thinking that I just need to replace shoes, all springs, adjusters and new drums. Only other thing I can think is the E brake, but I don't think that's what it is. Cylinders are new, shoes and springs were new and one adjuster was new.

I just hate to throw all that cash at it and then deal with this sh!t again. Both wheels have done it and only fix is to take off wheel, tighten adjuster fully tight and be VERY gentle when backing up and braking. Any ideas?? Would I just be throwing the money away?

put it in the shop and have a professional fix it. I don't know my rear brakes are screwed right now.

If you tighten the adjusters fully tight, of course it's going to get hot.

I believe the "automatic adjustment" only allows the adjusters to tighten - not "back off". Due to the way the little bar on the bottom of the "star" doesn't allow it to loosen up; only get tighter.

the star adjusters can be a pain, here is how i adjust the drums on my 89.

jack up one rear wheel
pull out rubber plug on back of drum
spin wheel and check for drag
adjust star adjuster with screw driver( i believe you pry up) until tire barely spins and casn hear/feel resistance
back off the adjuster until wheel spins with some drag.
do the other side.

You may want to recheck the way you installed the shoes. There's a size difference between the front facing and rear facing shoe. I think the larger shoe goes towards the front of the vehicle although I'm not sure of this as it has been a long time since I've replaced mine. Maybe someone else can chime in on this to help get it straight. Your described symptoms sound like this could be a possibility.

bigger shoe goes on the back.

Thanks for the tips guys! What I meant by tight was that the adjusters themselves were fully tightened so that the actual shoes were pulled in as tight to the hub as possible. Not that they were fully open, pushing the shoes way out. I didn't know about the bigger/smaller shoe, so that's something I'll have to check on.

I just went through a bit of hassle with the rear brakes on my swapped-in D44. The symptoms were similar, although mine was more a grinding drag and massive heat build-up. Turns out the center flanges of my drums were warped, pushing the drum outer edges too far inboard, causing the drums to ride the metal backing plate that the shoes are bonded to. I removed each drum, set it open-side down on smooth comcrete, and gave it a sharp whack with a BFH between each lug hole. This pushed the mounting flange more inboard, pulling the outer edge that was riding the shoes more outboard, and relieving the riding condition.

Well, the shoes were definitely on right (large ones in back). I just tightened the adjuster the whole way down (to pull shoes whole way in). I'll just see what happens from this point.

A mechanic friend said that it really sounds like an e-brake issue. I've looked at the adjustment screw before, but there's no way I'd be able to adjust it without cutting it off and getting a new bolt. It's way too seized and rusted. He mentioned something about bending something or other back where the cable for the ebrake enters the drum (basically to disable the ebrake). I'm just gonna wait and see what happens and then maybe look into that.

Be careful if you start screwing around with the e-brake cables where they go thru the backing plate. The end of the cable is prob. rusted and the prongs that hold in the backing plate will break off, and in some instances depending on the work done the cable can pull out of the backing plate.....you WILL be changing your undies if you run over your e-brake cable while driving down the road.I know of what I speak...lol.
Still sound like bad adjustment, did you replace all the brake hardware or just a couple of things.
The other thing is did you check the tension on your e-brake, not at the wheels but up along the drive shaft tunnel. If its super taught up there then you may have to back it off.

dizzymac said:

Be careful if you start screwing around with the e-brake cables where they go thru the backing plate. The end of the cable is prob. rusted and the prongs that hold in the backing plate will break off, and in some instances depending on the work done the cable can pull out of the backing plate...

Click to expand...

not to hijack, but a cheap/easy way to remove the cable is to put a small hose clamp around the "fingers" that hold the backing plate and tighten it 'til the cable can be pulled through and then remove the clamp-- not sure if this is obvious or not, but it took me forever to figure it out-- maybe I'm just slow!

--Shorty

dizzymac said:

Be careful if you start screwing around with the e-brake cables where they go thru the backing plate. The end of the cable is prob. rusted and the prongs that hold in the backing plate will break off, and in some instances depending on the work done the cable can pull out of the backing plate.....you WILL be changing your undies if you run over your e-brake cable while driving down the road.I know of what I speak...lol.
Still sound like bad adjustment, did you replace all the brake hardware or just a couple of things.
The other thing is did you check the tension on your e-brake, not at the wheels but up along the drive shaft tunnel. If its super taught up there then you may have to back it off.

Click to expand...

I've checked the cable before, and it doesn't seem overly tight, but I have nothing to gauge it by so who knows. All I know is that the hardware is so rusted that sh!t would surely start breaking if I tried to adjust it. Honestly, all I remember is that there was a really long bolt with a nut that was basically fused onto it (ebrake cable adjustment).

Re: hardware... new spring kits, shoes and cylinders in both wheels. new adjuster in passenger side, old adjuster in driver's side(both adjusters greased). Both OLD drums. I don't think it's the old vs new adjuster though because at different times, it's been *either* wheel that ends up running hot and causing the vibration issue.

Thanks for the added replies and info everyone!