I was having some pulsating when braking on my 1997 GMC K2500 Suburban (6.5L turbo diesel, 3/4 ton, 4×4). I hadn’t seen the brakes on this truck yet, so I put it up on four jackstands and pulled the wheels. The drums, rotors, shoes and pads all looked good. I was pleasantly surprised to see that the brake pads on the rear matched an extra set that I had ended up with that were too large for my other Suburban, a 1993 K2500 Chevrolet (5.7L gasoline, 3/4 ton, 4×4). To investigate further, I decided to pull the rotors.
As I would later learn, not only is this really hard on the 8 lug 8600GVW GM trucks, but I had already learned this lesson from the other Suburban, but had forgotten.
Rotor removal:
- Loosen lugs
- Loosen axle nut
- Jack vehicle and secure with stands
- Remove lugs and axle nut
- Remove four 15mm bolts that hold the hub to steering knuckle *** READ BELOW ***
- Pull hub off axle
- Remove ABS sensor from hub, or disconnect from frame rail, if attached
- Knock out lug studs from plate, being very careful not to damage the threads
- Separate plate, disc rotor and hub
- Installation is reverse of removal
Be extremely careful remove the four 15mm bolts. These are special bolts and cost five to seven dollars at a dealership each. They are torqued very high. I would strongly recommend dousing them in PB Blaster at least 24 hours in advance. Removal will require a long cheater bar. Use only high quality six point sockets. Take the time to either turn the steering wheel for each pair of bolts, or remove the tie rod ends.
I had three that would not budge. Heat did not help. A mild impact wrench did not help. Soon enough the bolt heads started to round off. “Bolt extractors” were laughably useless. In the end, I used special left-handed cobalt drill bits to drill the heads off the bolts. I started small and worked up to the size of the bolt just beyond the head, which is a little larger than at the threads. Thus I was careful to check my depth. I used progressively larger drill bits until I was able to remove the remains of the heads using an extractor.
Once the hubs was separated and I was able to remove it from the vehicle, I applied additional penetrating lubricant overnight. The next day I was able to break two of the bolts using a vise on the hub and a vise grip on the bolt. The remaining bolt wouldn’t budge. I went to my metal shop and tig welded a piece of angle iron to bolt remnants, headed the bolt and tried to use the leverage, but only ended up bending the angle iron. Then I cut the bolt off and drilled it out, but still could not get the bolt threads outs. I kept adding heat until I started to damage the hub. Lacking the correct size tap, and having damaged the hub, I replaced this hub altogether.
I happened to have a spare ABS sensor for this truck, due to getting the wrong one when working on the aforementioned previous truck. This was good, because when I had remove the sensor from this hub, the plastic around the pickup coil broke off. Ultimately, I suspect this sensor was all I had to replace to resolve my symptoms. However, due to the design I had to remove the rotors to get to it, so I put on new rotors and pads while I was able to.