99' Tahoe weird issue brakes?

[Jimbro]

My 99' Tahoe has 158,000 miles on it. I bought it with 98,000 and noticed a problem that seemed to be brakes. I replaced the brakes with the best I could get. It didn't fix the issue. What happens is, sporadically, I feel pulsing when I brake and then when fully stopped it feels like the rear of the Tahoe is lifted then when I depress the brake pedal I feel the rear drops. I have spent a lot of time and money on the problem and am about to give up. I looked up the problem on line and it looks like it is binding on the rear axel. Can anyone help? Thanks in advance.

 

[MO Viet Vet]

How high does your engine idle at a stop in drive?

 

[Jimbro]

I will double check but I believe 1,000 rpm

 

[MO Viet Vet]

Should be closer to 800 rpm. Plus I am a little confused. You said:

"I feel pulsing when I brake and then when fully stopped it feels like the rear of the Tahoe is lifted then when I depress the brake pedal I feel the rear drops."

So you are fully stopped to me means the foot is on the brake pedal, especially with the idle in gear at 1000 rpm and then you say you depress the pedal and the rear drops. How can you depress the pedal when your foot is already on the pedal? Don't mean to argue but the details are key here. Also, you said you replaced brakes. What did you replace? Again, details.

 

[Jimbro]

Really 800?...I get 800 when idling not in drive. What I meant was take my foot off the pedal...I replaced rotors drums pads and shoes. I can look up the brand but it was the best I can get. When I get the pulsing I also get the lock up and drop in the back. When I don't get the pulsing, there is no lock up or drop in the back. Also, very rarely, when it pulses then at a dead stop I take my foot off the pedal the Tahoe doesn't move then accelerate and I feel grinding as well as a bang that seems to come from the back. 2 things though, I took it to a friend who gave me some time in his shop and he sprayed the whole bottom with an oil spay. From nose to tail he spayed it and for about 1 day the issue stopped completely. The second thing is the U joints have never been replaced and another friend of mine said that could be the issue but it doesn't make sense to me. I'll look at my records to see if I am forgetting anything.

Thanks for this input by the way.

 

[MO Viet Vet]

Depressing the pedal is the same as apply the brakes. Hopefully you cleaned with a wire brush and used correct high temp lube at all pad and shoe contact points, caliper contact and caliper slides contact points. Replaced all rear shoe hardware. IMO the 1000 rpm at idle in gear is too high. Report back on that with exact info. Check the trans and engine mounts, also.

 

[Jimbro]

I didn't use the grease but I will, I didn't know about that. I will report back with the exact rpm. I have an OBDII reader.

Thanks a million

 

[Jimbro]

Hi raiderron, sorry it took so long. I ran into some really hard times. Anyway, I am back on track. My rpm on idle is 550. Aslo, the grease on the breaks cured my problem but took about 2 months to fully go away. Thanks a million! No one could figure out the problem for 7 years I own my '99 Tahoe. I am greatful for people like you out there.

 

[Gears]

Hard to tell without driving it but there are two things I can think of one is the drive shaft slip yoke causing a slip stick feel like you are getting rear ended at a stop light and the other is a false ABS activation which can be caused by a wheel speed sensor that is scewed. Usually the front sensors on the hub where the sensor meets the hub there is rust build up causing the sensor to read wrong. Good luck

 

[Jimbro]

Thanks, the issue has been resolved by greasing all the moving parts on the rear drum breaks. I used high quality high temperature high strength grease. I did think it was the yoke and the ABS. The yoke is ok but I pulled the fuse on the ABS because the sensor is covered with rust. The problem was still happening. I am good now. Raiderron was a huge help. Thank you for your suggestions. Keep them coming!!!!