96 Chevy Silverado Brakes

**hwm54112** · 08-15-2006, 07:27 PM

36K. miles. Was used as a second car, not as a truck. I’ve owned it for 1 year, 2000 miles. 3 times, when I hit the brakes at hi speed, it pulled real hard to the left. 1st 2 times I thought it was water, but third time road was dry

No sign of any brake problems ever. Brake job was done just prior to purchase. On last use, there seemed to be a heat build up through the lower part of firewall (city traffic). I stopped at a light, when I released the brakes, felt more like a parking brake being released. 1 minute later, ABS light went on, stayed on. I parked it 2 miles later. Brake pedal was normal, it braked normally. It did smell, (seemed electrical ). When I started it the next day, brake pedal goes almost to the floor. No ABS light, it still brakes (with reserve pressure I guess, but no pedal. The parts are expensive, $ 700.00 for the ABS hydraulic unit alone. How can I determine if it’s the ECM, hydraulic module, something else? I suspect the ABS hydraulic unit as there was a service bulletin and exchange agreement on the part. Obviously this truck hasn’t been used. And is just reaching the failure point of the module. Can see no hydraulic leaks anywhere. Master cylinder is full. Fluid is clean Everything points to the hydraulic unit. Contemplating trip to junk yard and replacing ecm and hydraulic unit if I can find a low mileage unit that’s been replaced. Any suggestions, guidance? Thanks for the help.

Bill

**Midnight Tech** · 08-15-2006, 07:38 PM

I know I sound like a broken record....but get somebody to pull those ABS codes to see what it says....it could be something minor.
I'd do some nosing around and see if you can find a modulator/ECM unit for that truck as well.

**hwm54112** · 08-15-2006, 07:56 PM

It was suggested I investigate the low peddle and correct that 1st and I just don't buy it. It just seems that the ABS could cause the pedal problem and not the other way around. Will the codes show a problem with the hydraulics? It's unclear if the ECM and modulator are seperate/can be replaced seperately?

**Midnight Tech** · 08-15-2006, 08:20 PM

ABS will not allow the booster to return the pedal to full up in some cases if it's acting up...yes...ECM and modulator are separate items on that vehicle.
EDIT:
ABS Hydraulic Unit - A1 CARDONE [Reman] 12-5034

**hwm54112** · 08-15-2006, 08:54 PM

Thanks Midnight

08-15-2006, 07:27 PM	#1 (permalink)
hwm54112 TSF Enthusiast Join Date: Oct 2005 Posts: 2,233 OS: WINXP	96 Chevy Silverado Brakes 36K. miles. Was used as a second car, not as a truck. I’ve owned it for 1 year, 2000 miles. 3 times, when I hit the brakes at hi speed, it pulled real hard to the left. 1st 2 times I thought it was water, but third time road was dry No sign of any brake problems ever. Brake job was done just prior to purchase. On last use, there seemed to be a heat build up through the lower part of firewall (city traffic). I stopped at a light, when I released the brakes, felt more like a parking brake being released. 1 minute later, ABS light went on, stayed on. I parked it 2 miles later. Brake pedal was normal, it braked normally. It did smell, (seemed electrical ). When I started it the next day, brake pedal goes almost to the floor. No ABS light, it still brakes (with reserve pressure I guess, but no pedal. The parts are expensive, $ 700.00 for the ABS hydraulic unit alone. How can I determine if it’s the ECM, hydraulic module, something else? I suspect the ABS hydraulic unit as there was a service bulletin and exchange agreement on the part. Obviously this truck hasn’t been used. And is just reaching the failure point of the module. Can see no hydraulic leaks anywhere. Master cylinder is full. Fluid is clean Everything points to the hydraulic unit. Contemplating trip to junk yard and replacing ecm and hydraulic unit if I can find a low mileage unit that’s been replaced. Any suggestions, guidance? Thanks for the help. Bill

08-15-2006, 07:38 PM	#2 (permalink)
Midnight Tech Admin/Head GreaseMonkey/Igor's alter ego/Grand Exalted PoohBah Join Date: Dec 2001 Location: SC Posts: 2,920 OS: Windows XP Home/Pro SP3/Windows 98SE/Fedora Core 6/RH 7.2 with Autopoint/TAMS II	I know I sound like a broken record....but get somebody to pull those ABS codes to see what it says....it could be something minor. I'd do some nosing around and see if you can find a modulator/ECM unit for that truck as well. __________________ Please post all questions in the appropriate forum. Questions sent by email or PM will not be answered. Sharing my life...with my Imzadi! Interested in Trek gaming? Check out the Dynaverse! Proud supporter of the Carolinas Aviation Museum. If we have helped you in any way, please donate to keep TSF up and running!

08-15-2006, 08:20 PM	#4 (permalink)
Midnight Tech Admin/Head GreaseMonkey/Igor's alter ego/Grand Exalted PoohBah Join Date: Dec 2001 Location: SC Posts: 2,920 OS: Windows XP Home/Pro SP3/Windows 98SE/Fedora Core 6/RH 7.2 with Autopoint/TAMS II	ABS will not allow the booster to return the pedal to full up in some cases if it's acting up...yes...ECM and modulator are separate items on that vehicle. EDIT: ABS Hydraulic Unit - A1 CARDONE [Reman] 12-5034 __________________ Please post all questions in the appropriate forum. Questions sent by email or PM will not be answered. Sharing my life...with my Imzadi! Interested in Trek gaming? Check out the Dynaverse! Proud supporter of the Carolinas Aviation Museum. If we have helped you in any way, please donate to keep TSF up and running! Last edited by Midnight Tech; 08-15-2006 at 08:23 PM.

08-15-2006, 07:56 PM	#3 (permalink)
hwm54112 TSF Enthusiast Join Date: Oct 2005 Posts: 2,233 OS: WINXP	It was suggested I investigate the low peddle and correct that 1st and I just don't buy it. It just seems that the ABS could cause the pedal problem and not the other way around. Will the codes show a problem with the hydraulics? It's unclear if the ECM and modulator are seperate/can be replaced seperately?

08-15-2006, 08:54 PM	#5 (permalink)
hwm54112 TSF Enthusiast Join Date: Oct 2005 Posts: 2,233 OS: WINXP	Thanks Midnight