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  1. #1

    Default soft brake pedal ~ 99 K1500

    ever since i have had my 99 K1500 obs the brake pedal has felt soft but after i replaced everything except the abs module the brakes are even worse and barley stop the truck. i had it to the dealer to to have the abs system bleed and they said everything bled fine but they barley work the guy at the dealer said he had no clue what would cause the problem. i am wondering could a bad abs module cause it to feel like their is air in the system?

  2. #2

    Default

    You might try bleeding them again or having a brake shop instead of dealer do it. did you replace the master cylinder because sometimes that needs to be bled separately from the rest of the system (should be bench bled before going in). I know for the master it can be bled from the connections at the master but I dont remember the proper way as it has been a long time since I have done one. when doing the regular bleeding make sure to go from the furthest wheel and work towards the master (RR, LR, RF, LF)
    David
    2004 Silverado 2500 Crew Cab 4x4, AMSOIL EA air filter, Granatelli MAF sensor, Throttle body spacer, Magnaflow exhaust (true dual to 2 in 1 out muffler), 6" ProComp lift (add a leaf and 5" superlift rear block), Bilstein shocks, 35's (Cooper Disoverer ST) and 4.10 gears, Rhino Liner, EGRUSA fender Flares and widow visors, extended stainless steel brake lines, firestone airbags w/onboard air compressor, Pioneer Avic X940BT navigation, Accel backup camera.
    http://www.gmtruckclub.com/forum/sho...Silverado-2500
    1960 Land Rover Series II 88
    2001 Pontiac Sunfire
    2013 Toyota Avalon Limited (Wife's Car)
    NRA Life Member

  3. #3

    Default

    I replaced the master cylnder after having the same problem with the old one. The master was bench bled and the entire system was bleed multiple times with no improvement. I finally just got rid of the abs im just waiting for some lines to test it out.

  4. #4
    Sr. Mechanic Ethan's Avatar
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    Sep 2009
    Location
    Cedar Park, TX
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    150

    Default

    Have you replaced all your brake lines? Have you made sure that your wheel cylinders and calipers are not leaking? Have you checked your proportioning valve and or your combination valve for leaks or bad valves? I suspect a leak somewhere.
    1994 Chevy Silverado 1500 Ext Cab 350 cuin TBI in dark Chevy blue
    160,000+ miles
    Original paint
    Original interior
    Original engine and tranny
    wrecked twice stolen once
    Diamond Plate bed rails
    Power windows
    Original Alloy wheels
    Original fancy smancy cup holder
    Tow package
    Original plastic bed liner
    K&N Cone Air Intake
    Dual MagnaFlow exhaust(not true dual) with chrome tips
    MSD Street Fire Performance Ignition coil

  5. #5

    Default

    Everything except the abs, and booster has been replaced including the lines and their are no leaks. Even when I got the truck the brakes were not that good and the pedal was soft but not as bad.

  6. #6

    Default

    look into the booster, since most everything has been done but that and ABS. check the vacuum lines going to the booster for leaks, but the boosters themselves can go bad.
    David
    2004 Silverado 2500 Crew Cab 4x4, AMSOIL EA air filter, Granatelli MAF sensor, Throttle body spacer, Magnaflow exhaust (true dual to 2 in 1 out muffler), 6" ProComp lift (add a leaf and 5" superlift rear block), Bilstein shocks, 35's (Cooper Disoverer ST) and 4.10 gears, Rhino Liner, EGRUSA fender Flares and widow visors, extended stainless steel brake lines, firestone airbags w/onboard air compressor, Pioneer Avic X940BT navigation, Accel backup camera.
    http://www.gmtruckclub.com/forum/sho...Silverado-2500
    1960 Land Rover Series II 88
    2001 Pontiac Sunfire
    2013 Toyota Avalon Limited (Wife's Car)
    NRA Life Member

  7. #7

    Default

    After a while of thinking I decided to pull the master cylinder off and measure the bore and sure enough it was 1 inch not 1 1/8 like it was suppose to be.

  8. #8

    Default

    good thinking and hopefully that will fix it all.
    David
    2004 Silverado 2500 Crew Cab 4x4, AMSOIL EA air filter, Granatelli MAF sensor, Throttle body spacer, Magnaflow exhaust (true dual to 2 in 1 out muffler), 6" ProComp lift (add a leaf and 5" superlift rear block), Bilstein shocks, 35's (Cooper Disoverer ST) and 4.10 gears, Rhino Liner, EGRUSA fender Flares and widow visors, extended stainless steel brake lines, firestone airbags w/onboard air compressor, Pioneer Avic X940BT navigation, Accel backup camera.
    http://www.gmtruckclub.com/forum/sho...Silverado-2500
    1960 Land Rover Series II 88
    2001 Pontiac Sunfire
    2013 Toyota Avalon Limited (Wife's Car)
    NRA Life Member

  9. #9

    Default

    Changed out tthe master and now the brakes feel better than they ever did. Now I just have to try to send the old one back to summit I still have the receipt from allmost a year ago showing that I ordered the right one.

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