Brake problems on a Dakota

[BernieB]

This is my g/f's '97 Dakota 4x4 with a 3.9L and rear ABS.

About four years ago, after it failed state inspection for front brakes, I put on new rotors and pads. I bought good quality parts, Delco rotors and Raybestos pads, and all was good for about a year and a half, then I started getting some pedal pulsation. I figured a rotor probably warped and, since we were getting ready to head out west, I took it to a good loacl shop that I trusted. Had them do an oil change and check the rotors. The rotors were warped so we went ahead and cut them and put a nice non-directional finish on them. New pads were installed and I was good to go. Hopped in, started it up, drove to the driveway and braked... and felt some pedal pulsation. Got to the corner and braked, and the pulsation was worse than ever... as bad as I've ever seen in almost 40 years of working on cars. Turned around and went right back.

The owner, who is a top-notch mechanic, wouldn't believe the rotors had warped that quickly and hopped in to take a spin. He didn't even make it to the driveway before he backed up and drove it straight to the lift.

Pulled the rotors again, put them back on the lathe (I was saying get new rotors at that point - he was saying things I can't put here, and swearing he'd get the cut right this time) and checked them. The warp was visible but he felt he could still cut 'em and be within spec so we did. This time we remounted them and put a dial indicator on them and they were straight and true, less than 3 thousandths variation. Put the wheels back on and he took it for a spin.

Got to the driveway, pulled out in the street, came in the other driveway and right back on the lift. He yelled to one of his guys to order a pair of rotors and some new pads, "and none of that cheap junk!" Yep, the rotors warped again. While we waited for the new parts we put the dial indicator on it and both rotors were so warped they were beyond the range of the indicator.

We both agreed, it was the worst case of rotor warp either had ever seen.

We got the new rotors (on his dime - wouldn't let me pay for them because he felt he screwed up in not replacing them when they warped after the first cut) and everything was perfect.

Flash forward to about three weeks ago...

I had noticed over the past month that I was getting some pedal pulsation again, but not too bad. The truck was due for inspection so I figured I'd wait and see how the pads looked during the inspection.

Then, a week before I took it for inspection my g/f was heading to the airport and the rears started making a sound best described as a running angle grinder dropped into a half full drum of loose nuts and bolts... just backing out of the garage!

Okay, so I took her to the airport in my truck and came home and ripped apart the rear brakes. Nothing, nada, no problems at all. Hardware was good, shoes were a little worn but still had plenty of meat, nothing broken, drums smooth with no ridges.

I put in a set of Napa semi-metallics anyway, cleaned everything up and it seemed fine. Within a day the rears started groaning and squealing. By the end of the week, when I took it for inspection, it was getting downright embarrassing! I've heard brakes on garbage trucks that were quieter.

I looked everything over while it was on the lift being inspected (it passed) and could see nothing wrong, front or rear.

Two days later I couldn't stand it anymore so I pulled the rear drums and gave the shoes a slight bevel on the leading edges. Just looking at the shoes you could see the pattern of how they'd been chattering when they squealed, so I gave them a light sanding, cleaned everything again and reassembled. Tightened up the adjusters to the point were I could feel a slight drag and took it for a test spin.

No problem. Braked smooth and straight. No noise, no pulsation.

Monday the g/f tells me the noise is coming back, and she's feeling some vibration when she brakes.

Tuesday, when she pulled into the garage, I could smell hot brake pads, and she said it was vibrating at every stop. I planned to pull the drums after dinner when it had time to cool, but never got to it. Then the water heater blew, the cat got sick, and things got put off.

Today, after dinner, I took the truck for a test drive. The first couple of stops were fine. No noise, vibration, chatter or smell. By the third stop I was starting to hear a squeal and feel some vibration. After several runs in a parking lot it was squealing loud, and groaning at every stop. By the time I got home and pulled in the garage I was getting strong pedal pulsation and it sounded like both the front and rears were squealing.

Jacked up the left side and pulled both wheels, front and rear.

Nothing, nada, zip. Everything looks perfect. No dust, no rust, good hardware, clean backing plate, pivots lightly lubed with white lith, but chatter marks on the rear shoes again.

My next step would normally be to pull the drums and get 'em cut, but I can't find any shop in this area that will cut drums (I asked around after replacing the shoes). The nearest one seems to be the guy who cut the rotors for me, and that's a two hour drive each way, without traffic.

Anyone have any other suggestions? I know all the usual things that cause brake noise, but I'm not finding any of those causes here.

[crabtruck]

Could be chatter at rear from ABS self test,
maybe try unplugging and see if that quiets it.
Found this TSB, may be long shot.

[BernieB]

Originally Posted by crabtruck

Could be chatter at rear from ABS self test,
maybe try unplugging and see if that quiets it.
Found this TSB, may be long shot.

I thought about the ABS, but I know what that feels like and this is different. I may unplug it and try it anyway though, just to be sure.

As for the TSB... Good catch, and I appreciate it, but it only applies to 4x2's and this is 4x4 I wish it were that easy!

[crabtruck]

4x2's ? Fine - throw away fronts and retry.

[BernieB]

Originally Posted by crabtruck

4x2's ? Fine - throw away fronts and retry.

Rear wheel bearings then? Possible I suppose, but I didn't notice any play or looseness in them while I was pulling the drums or working on the brakes.

If I have time tomorrow I'll check them, but I've got to pick up the cat at the vet in the afternoon, and take the old water heater to the dump. It might have to wait until Saturday.

[crabtruck]

I was kidding but now that you mention it, it's maybe worth a look.
Good luck with the cat.

[BernieB]

Okay, I finally got a chance to look at the brakes again today. Since the last time I checked them they'd just gotten worse and worse, until it's almost embarrassing to drive the truck.

Pulling the drums I noticed the left side was not as "snug" as the right, and I'd adjusted them to about equal last time, so I checked over the self adjuster but it looks good.

The "chatter" marks are easy to see on the shoes, and in the dust marks on the drums. What I really think I need to do to fix this is have these drums cut, but I can't find anyplace local that will do them. So, I did the next best thing... Got out some 220 grit paper and gave the shoes a light sanding to remove the chatter marks, and then did a little sanding on the drums. I'm not satisfied with the drums though, so I'm going to do them again, with a flap wheel in the drill this time.

I'm attaching pics but they're small due to the forum limitations, so I also uploaded the full sized ones to my own site and I'll try including links to them. (#'s 01-03 are passenger side)

http://spwaw.com/bwb/bluehawk/brakes01.jpg
http://spwaw.com/bwb/bluehawk/brakes02.jpg
http://spwaw.com/bwb/bluehawk/brakes03.jpg
http://spwaw.com/bwb/bluehawk/brakes04.jpg
http://spwaw.com/bwb/bluehawk/brakes05.jpg
http://spwaw.com/bwb/bluehawk/brakes06.jpg
http://spwaw.com/bwb/bluehawk/brakes07.jpg

[BernieB]

Any and all suggestions are welcome. This one is starting to get me frustrated. I'm 53 years old and I've been doing brakes since I was 14 and never had a set squeal and chatter this bad.

[crabtruck]

Could be a trick of the camera, but cable looks loose to me above the spring.
Not binding as comes around shoulder is it?

[leolkfrm]

maybe it does not like semi-metalic! had a car that only liked organic