Adjust the equalizer.

 

the equalizer does not have adjustment. it is just a plate that attaches the cables together

 

Have you replaced the parking brake pads? Those eventually disintegrate and wear down from age and use and could very well be the problem you are now having....

 

The park brake shoes must be adjusted before the park brake pedal is adjusted!
Remove both rear rotors clean the rust ridge from the drum, turn the adjuster, and check with the rotor on, should be close with no drag. Same for adjusting DRUM brakes. Mount rotors and secure with a couple lug nuts, depress parking brake, and with force attempt to move rear rotors by hand. If they move, more adjustment needed, if not your done. Reinstall everything, then adjust the parking brake pedal.

 

Hello laine and everyone… I went ahead and purchased an ACDelco e-brake controller #20803236 from local partstore. This is listed for '08-'10 H2, but it made no sense to me why '03-'07 would be a different part since the body and chassis didn’t change anywhere around these brake components. Only the dash and console design changed. Sure enough this controller is perfect replacement for the 2003. Only the release handle is different design. I installed it in only an hour and used my existing release handle and cable.

Immediately, after following the initial adjustment process, everything seems to be adjusted up correctly and the mechanism is nice and smooth and quiet. I haven’t put things back together under the dash yet, so haven’t started it and pulled it out of the garage for test. I'll update hopefully tomorrow night with good news.

One thing I did notice on mine. I installed AMP Research power running boards on my H2 about 5 years ago. The front driver frame mount for the running board was interfering with the e-brake cable. Im sure I realized it at the time of installing, but never though much about it after. Now Im thinking this must have caused some issue over time with the old controller adjustment mechanism. I drilled a new hole in the frame mount point for the front e-brake cable to move it over a bit. So now has no interference.

So I feel very confident that ACDelco #20803236 is a legit supersede for ACDelco #15952290.

 

Laine, u didn't use the cable that came with the the new park brake module gm part # 25780187, do u happen to still have that cable? It fits my sierra, GM has since discontinued it and I would be willing to buy it from you!