Fixed it...ground issue with the relay between the two batteries.
Big update today:
I just tested out the new Hawk Super Duty (SD) pads; I had been running Hawk LT. Even though I'm running 3/4t calipers (larger piston then 1/2t), I decided to go with a 1/2t pad. The 3/4t pads need to be trimmed down to fit the 6lug hat and it just didn't seem like the contact patch was optimized...so I went back to 1/2t's.
Also, when I completed this test, I made a few changes to my truck...most notably the correctly valved shocks. 5150's are too light for my truck, but the 5100's dampen perfectly.
It's impossible to tell how much each component change reduced my stopping distance. But even with the extra weight of x2 steel bumpers, winch, full spare, steel roof rack, etc the SD's produced some really nice results.
HYDROBOOST, 3/4t Master, 3/4t PS pump, 3/4t calipers, 1/2t Hawk SD (Super Duty) pads, 285/70R17, 5.0" lift
1st pass - 127 feet
2nd pass - 117 feet
3rd pass - 107 feet
4th pass - 112 feet
5th pass - 108 feet
For the complete test results and the difference between hydro and vacuum, I posted it here - http://www.gmc4x4.com/topic/119-spongy-brakes-testing/
Big update today:
I just tested out the new Hawk Super Duty (SD) pads; I had been running Hawk LT. Even though I'm running 3/4t calipers (larger piston then 1/2t), I decided to go with a 1/2t pad. The 3/4t pads need to be trimmed down to fit the 6lug hat and it just didn't seem like the contact patch was optimized...so I went back to 1/2t's.
Also, when I completed this test, I made a few changes to my truck...most notably the correctly valved shocks. 5150's are too light for my truck, but the 5100's dampen perfectly.
It's impossible to tell how much each component change reduced my stopping distance. But even with the extra weight of x2 steel bumpers, winch, full spare, steel roof rack, etc the SD's produced some really nice results.
HYDROBOOST, 3/4t Master, 3/4t PS pump, 3/4t calipers, 1/2t Hawk SD (Super Duty) pads, 285/70R17, 5.0" lift
1st pass - 127 feet
2nd pass - 117 feet
3rd pass - 107 feet
4th pass - 112 feet
5th pass - 108 feet
For the complete test results and the difference between hydro and vacuum, I posted it here - http://www.gmc4x4.com/topic/119-spongy-brakes-testing/
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