Brake help, PLEASE

[scoobyjwc]

1995 Tahoe LT, 5.7 4wd
I have tried everything. My brakes have had a pulsation/shaking problem for years. I've replaced EvErYtHiNg.
Booster, master cylinder, pads, shoes, rotors, drums, calipers, wheel cylinders, front shocks, tie rods, ball joints, abs sensors, abs computer, vapor cannister...all of these parts are brand new.
BUT MY BRAKES STILL SHAKE.
My only ideas now are rear suspension or the adjusters on the drums, but I don't think those would cause this. I could be wrong.
Any ideas or input would be greatly appreciated. I am absolutely determined to solve this.

 

[97YukonNZ]

Hi welcome to the forum.
Bent rear axle maybe? A bent rim? Wheels out of balance or bent drive shaft.
A few things to consider,hope this helps.

 

[OR VietVet]

Yes, welcome to the forum from Oregon. Let's start with the basics first. Only pulses/shakes when apply brakes? At any speed? Is driving smooth till apply brakes? Had you done ANY mechanical work or lifted the rig in any way before all this started? Your drums slide on to the hub end of the axle shaft. That needs to roll true. Had you hit a curb or pot hole recently. Front hubs old or new? Did you just slap on the drums and rotors without checking for true? Have you checked the shoe backing plates for grooves allowing the shoes to not lay flat? Have you checked the caliper mounts to make sure they are clean and flat and allow smooth movement of the caliper? Did you replace all brake hardware on the front and back? Have you tested and checked the wheel/axle bearings, front and back? If you drive fast enough and lock up the brakes, what does it do? Pull to left or right or stop straight? ABS working?

 

[scoobyjwc]

Yes, welcome to the forum from Oregon. Let's start with the basics first. Only pulses/shakes when apply brakes? At any speed? Is driving smooth till apply brakes? Had you done ANY mechanical work or lifted the rig in any way before all this started? Your drums slide on to the hub end of the axle shaft. That needs to roll true. Had you hit a curb or pot hole recently. Front hubs old or new? Did you just slap on the drums and rotors without checking for true? Have you checked the shoe backing plates for grooves allowing the shoes to not lay flat? Have you checked the caliper mounts to make sure they are clean and flat and allow smooth movement of the caliper? Did you replace all brake hardware on the front and back? Have you tested and checked the wheel/axle bearings, front and back? If you drive fast enough and lock up the brakes, what does it do? Pull to left or right or stop straight? ABS working?

I've had the truck for 11 years, and have done lots of mechanical stuff in the past. This brake issue started maybe 2 years ago after a 6 month period of not driving it at all.
Driving is incredibly smooth until I hit the brakes, and they shake at any speed. It is more severe at higher speed and with abrupt stopping.
Rotors and drums are true and flat, and no potholes or curbs hit since they were replaced and I had an alignment done.
The front hubs are old but the bearings seem fine, I am checking the rear bearings today or tomorrow.
I have not checked the drum backing plate, but I'm replacing the self adjuster so I will do that.
Caliper mounts seem great to me, guide pins are in great shape. Abs works, and the shaking pulls left to right so that I stop straight without hands on the steering wheel, but it is very very noticeable.

 

[exp500]

Can you narrow it down to front or rear shake? Does the truck drive nice even on a rough road when you don't hit brakes? Does driving in rain feel better or worse with/without brake use?
Test your 4x4 and ABS on sand. All Normal?

 

[scoobyjwc]

It's kind of an all over shake, I've been trying to narrow it down without success. Also it rarely rains here so I'm not sure, but without hitting the brakes; rough roads, dirt, sand...a smooth ride until I need to stop

 

[OR VietVet]

I would also check the play at the steering gear shaft where pitman arm attaches. Also, check for any cracks at the steering gear mount and at the idler arm mount and play at the idler arm. I am amazed that something like this that can easily be duplicated has taken 2 years to get here. Parked for 6 months could cause dry bearings and may be rear axle bearings. Hell, I am just guessing at this point.

 

[scoobyjwc]

I'll get to work on all these suggestions and let yall know what works and what doesn't. Thanks for the suggestions!

 

[97YukonNZ]

I was reading earlier that you said the vehicle had been parked up for 6 months. Any chance that there was some build up from where the pads sat resulting in high spots or brake line on the disc's? Would explain a higher amount of shake at speed when braking

 

[scoobyjwc]

I was reading earlier that you said the vehicle had been parked up for 6 months. Any chance that there was some build up from where the pads sat resulting in high spots or brake line on the disc's? Would explain a higher amount of shake at speed when braking

Yeah, there definitely was. However I've replaced the calipers, pads and discs since then.