Rear Brake Severe Pulsating

[Havasubum]

I own a 2006 GMC Z71 4x4 with 16k miles and rear drum brakes. I tow a boat with it twice a month for a 5 mile round trip. The rest of the time I drive it mostly on the freeway without a load from CA to AZ. I DO NOT use it on mountain roads and have never overheated the brakes. I just took it into the dealer due to severe brake pulsation when the brakes are applied. The dealer says the rear drums are egg shaped and need to be turned. When I am not using the truck it is parked for lengthy periods in my driveway with the parking brake applied. Can anyone tell me why the drums went bad and how I can avoid it in the future?

 

As a side note I just had the steering shaft replaced on a TSB. I am beginning to feel that I should not have purchased this vehicle.

[zvmax]

I own a 2006 GMC Z71 4x4 with 16k miles and rear drum brakes. I tow a boat with it twice a month for a 5 mile round trip. The rest of the time I drive it mostly on the freeway without a load from CA to AZ. I DO NOT use it on mountain roads and have never overheated the brakes. I just took it into the dealer due to severe brake pulsation when the brakes are applied. The dealer says the rear drums are egg shaped and need to be turned. When I am not using the truck it is parked for lengthy periods in my driveway with the parking brake applied. Can anyone tell me why the drums went bad and how I can avoid it in the future?

 

As a side note I just had the steering shaft replaced on a TSB. I am beginning to feel that I should not have purchased this vehicle.

 

I bought an '06 a year ago and repeatedly took it back to the dealer because I was unable to stop smoothly. I would not describe it as extreme but -- unacceptable in a $34k truck. They just looked at me cockeyed and told me there was nothing wrong with it. I kept after them including going to another dealer with my complaints for their write up. They finally bought it back. The GM rep said they were having difficulties with the rear drums keeping their round (getting that was like pulling teeth). One of the other issues that the 2nd local dealer (who I wouldn't trust further than I can see them - if that far) said my steering shaft was completely dry and misaligned which they supposedly fixed. My advice is keep after them. I was fortunate in being able to get one of the first NBS's due to the buyback. It cost an extra $3k to get the Max package but the 4 wheel disk brakes were worth it. No way I would take another one with drums after the last experience. It was almost my last chevy (#7). This truck has not had any of the same problems. It did have to be towed in for starter problems - GM forgot to tighten the bolts so one fell out and the other was loose. I guess the first ones to get laid off are the quality inspectors -- which leads to further lay offs in a year or two.

[asilverblazer]

I can't wait for a reasonable priced to kit to convert my drums to discs.

[Cadha13]

At 38k miles, my drums on my truck still work perfectly. Better brakes than the 4 wheel disks on the 2k Impala. Gm had major problems of rusting and pedals going to the floor with no stopping with the 4 wheel disk system and changed in 05 with beefier fronts and good sized rears. Over compensated from previous mistakes. If you still need 4 wheel disks, look at the 07 NBS and see if thew would work and change your whole hydraulic system at the same time, pedal forward. Different fluid rates for disk/drum vs. all disks. I measured the brake sizes of my truck and of a 1978 K20, they are the same due to same mass. Try stopping a 1978 GMC 1500 with no power brakes in a new state and see a difference. Very hard pedal.

[scottmoyer]

You aren't the only one with the rear brake pulsating. I have had this issue since day one and have had it checked multiple times by the dealer. I was told the runout could be the issue, but was never detected. I'm just waiting for new brakes to be needed and I will swap them with better.

 

In regards to buying this vehicle, you will not find a better built truck. Small gripes and complaints that we have are just that, small. The toyota crew are fighting bad transmissions!

[Havasubum]

You aren't the only one with the rear brake pulsating. I have had this issue since day one and have had it checked multiple times by the dealer. I was told the runout could be the issue, but was never detected. I'm just waiting for new brakes to be needed and I will swap them with better.

 

In regards to buying this vehicle, you will not find a better built truck. Small gripes and complaints that we have are just that, small. The toyota crew are fighting bad transmissions!

 

That's discouraging news. What brake conversion kit do you think you will buy? I talked to the folks at SSBC. They claim that the swap will not require any mods to the master cyl, proportioning valve/ABS brain, or ABS sensors at the wheels. The kit for the rear is $1500 and the front calipers (using the stock rotors) is around $930. That's a ton of money out of the bank account to make up for poor GM engineering. I'm not sure I can justify spending that much money, especially since I'm going to have to re-gear to 3.73.

 

Take care

[asilverblazer]

They claim that the swap will not require any mods to the master cyl, proportioning valve/ABS brain, or ABS sensors at the wheels. The kit for the rear is $1500 and the front calipers (using the stock rotors) is around $930.

 

I like that first part but that second line, sheesh. My point was affordable.