siZors

Hey guys! I've been going crazy with a brake problem that I've been having. It should be fairly simple, but I keep failing over and over. 89 Pickup.

One month ago my brakes are screaming and I realize it's time to replace them. Take off the old ones, pads are trash, rotors are trash, good thing I'm replacing them. I notice the axle is leaking oil, probably should replace that soon. I sand the mating surface of the hub with a little sandpaper, new rotors and pads on (Centric), and right off the bat I get a horrible shaking when braking. Well, the calipers looked pretty bad when I did the job, maybe I should get new ones. Got some rebuilt calipers, throw them on, still more shaking. Damn, "I must have got warped rotors" I think, that sucks! So I go off to NAPA, get a new set of rotors and pads, and get two new axles while I'm at it.

I put on the new axle, new rotors and pads. and again, the horrible shaking. Hmm I think. Maybe I didn't set my axle nut right (I was using the hammer and screwdriver method). FINE. I'll go get the tool. I order a 54 mm socket, and got a dial indicator while I was at it. Before I take apart the hub I measured LH throwout at 0.002" and RH at 0.0038", not great. I take apart the hub again, I swapped LH and RH for the hub and rotor (to see if things follow), and put the hub back together. At this point, every single bolt with a torque spec is to spec. The bolts holding the rotor to the hub were torqued in a star pattern, the inner axle nut was torqued using the common method of going to ~50 ft-lb, spinning, backing off, spinning, 50 ft-lb, spinning, backing off, spinning, 22 ft-lb. Should give pretty close to the proper bearing setting.

Before putting the wheels back on, I measure the runout, and the LH is 0.0032", RH 0.002". Therefore, I wasn't surprised when my brakes were shaking on my test drive.

At this point, I've replaced nearly the entire brake system other than the hub and the plate the calipers bolt on to. My plan next is to get yet another set of rotors and pads, take apart the hub, use a wire-brush on a dremel to get the mating surface on the hub VERY clean, put it back together and check the throwout before driving on it. If the throwout is still out, I won't drive on it so I don't trash another set of rotors. (I'm not made of rotors!) If that doesn't work, I'm running out of options. Perhaps I need a new hub?

I thought I'd throw my struggles up here in case anyone has any advice or thoughts on what the problem might be. I'm getting to be an expert in taking apart the locking hub since I'm doing it every week!!

dropzone

iTrader: (6)

year? model- IE: truck/4runner? miles?

wallytoo

iTrader: (1)

says "89 pickup" in the very first paragraph.

siZors

Yep, an 89 Pickup, 22RE 4WD regular cab... around 230k on the body although most every part has been replaced by now

akwheeler

Here's a couple of thoughts and questions for you:
did you do anything to the rear brakes? any chance that is where your vibration is?
does your steering wheel shimmy when you are braking or do you feel it more through the seat? is the pedal pulsating?
when you are checking runout you should also be checking rotor thickness.
One of your first comments was that you replaced the calipers, just fyi, they will not be the source of a vibration. They can cause the rotor to overheat if they do not release properly and that will warp rotors, so technically they can CAUSE a vibration but the SOURCE will be the rotor.
If you lightly apply your parking brake (keep the handle from locking and be careful) while you are moving you can tell if there is a vibration from the rear brakes since it will not apply the front brakes.

siZors

I think you may be on to something. I did replace my drums/shoes/cylinder/springs on the first brake job. It was so easy compared to the discs I didn't think I could have messed that up. Unfortunately, I also replaced the front and rear parking brake cables (OEM), and annoyingly the front cable is a little too long, so even with the rear cable adjustment all the way in, it's not enough for the handle in the truck to actuate the brakes. I'll need to shorten that front cable soon! But I went out and tied a rope to the lever arm to engage the parking brake and drove it down the block, and low and behold, my truck was shaking (less severely) in the same way as when braking. I guess this tells me it's probably an issue with my drum brakes and not the front.

The shaking seems to come from everywhere. So, I feel it through the pedal, also through the seat, and you can literally see the dashboard bouncing up and down through the shaking. It's a proper earthquake in there!

Thanks for the info on the calipers. I had kind of guessed that bad calipers wouldn't cause shaking, but sometimes when I think I know something it turns out I'm totally wrong... at $30 a pop I figured it was worth not having to worry about the limits of my knowledge, or about my rusty calipers failing me, but it's good to know I wasn't too far off.

I guess I'm going to do some research into what can cause shaking in drum brakes since it sounds like that might be my real problem. Is it possible I received out-of-round drums? Or is it possible I screwed something up when installing them?

siZors

I should add that the shaking seems worse at low speeds. It's there at high speeds, but it's quick pulsing and not that violent. As I slow down, it gets more and more violent.

akwheeler

So, here's what can happen with rear brakes, if they are over tightened or the parking brake cable doesn't release all the way they will overheat and the drums will warp.
You also need to be diligent with cleaning the drum mating surface on the axle so that everything spins true. could also be a bad set from the parts store, not common but I've seen it.
fixing the rear brakes doesn't mean you will totally get rid of your vibrations, but you already know for sure that there absolutely is an issue there and you'll never be rid of all your vibrations unless you fix them.

jazz1

I replaced rotors on wifes Camry twice in a month due to shaking. It was faulty rotors and pads first time, second time it was faulty rotors. 3rd time no issues, used whatever premium rotors and pads Napa supplied.. There is way too much junk on the market when it comes to automotive components JMHO

old87yota

I personally would go for either OEM or the "Premium" line at your favorite parts store for Shoes/Drums or Pads/Rotors.

It seems like the cheaper parts store brands just don't reliably give you smooth, quiet braking.

Also, are you sure you got the right parking brake cables?

siZors

Thank you guys! I think I've fixed my problem. I'll detail it here for anyone who encounters something similar in the future.

In the previous post I had jury-rigged my emergency brake lever, drove down the block and got the horrible vibration. Holy cow, all this time I've been chasing my complicated disk brake system, maybe it was the simple drum brakes in the back acting up all along. With the idea of using ropes to engage my parking brake fresh in my head, I figured why not try and rig each drum separately? So I took a ratchet strap, hooked it to the parking brake lever on the passenger side drum brake and took off down the road. No vibrations. Alright... so I stopped and moved the strap to the drivers side, and lo and behold, the vibration is back with avengence!

With the vibration isolated, I took off the offending drum and lo and behold the shoes have a weird bumpy pattern on them. Luckily for me, my buddy has an 884Runner that he was planning to do brakes on, so had a spare drum and shoe set, so I threw one of his on. I take off down the road and the vibration is gone!!

So the problem is that the drum was out of round. It's possible I over-tightened the adjuster the first time I did it, although the shaking was pretty much instant (during the first test of my brakes I had the shaking). I feel like if I had over-tightened it, it would have taken at least a little bit of driving to overheat and warp the drums, so maybe I just received an out-of-round drum.

I'm pretty sure it's the right cable, the dealer cross-referenced the VIN when I got it, although maybe they sent the wrong part? Unfortunately I bought it a long time ago and sat on it, too lazy to change it so, if it were wrong it might be hard to change it. I guess I just got so used to parking my truck in 4-low that I barely forgot I was missing an emergency brake! Made it hard to motivate myself to change it...



Attaching ratchet strap to individual parking brake lever

Tighten ratchet strap to engage parking brake

Bumpy wear pattern on shoes

Mr. Z.

Glad to hear you sorted the issue out.

I've also had a recent issue with ordering new parts that were faulty. While working on the rear drums in my VW I had a new set of drums arrive and at least one was out of round, and a wheel cylinder seal was bad on a new part. It's likely the last time I order any parts from Centric. On a side-note, my supplier ordered me a new wheel cylinder (also Centric), this one was made in Italy, not China. The part looked identical to the OEM part...casting, rubber boots, etc., unlike the same part number from China...casting was clearly inferior and quality of materials was less than inspiring. Too bad one can not select country of origin with some manufactures.
...OEM for the win!

Cheers