97 1/2 ton bleeding the brakes

Discussion in 'Chevy Truck Forum' started by txeye1, Mar 11, 2010.

  1. txeye1

    txeye1 Member

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    Background info...97 1/2 ton extended cab ,2 wheel drive..auto trans...350 engine.....Just replaced entire front end..rotors ...cap...did not replace back.....attempting to bleed brakes...have cross bled, back to back...then front to front.....Replaced master cyc. with new from napa.....
    Will bleed brakes staticly ....I have a full petal......crack the truck up...petal goes to the floor....I repeated the same process above with engine running...no air in system...but still goes to the floor.

    can anyone give me some tips.....
     
  2. Case 7230

    Case 7230 Senior Member

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    You still have air in the system. The brakes should be bled right rear, left rear, right front, left front.
    However I would think that you have full ABS and that can complicate matters. Sometimes you need a scanner that can cycle the ABS solenoids while bleeding.
    I assume you did bench bleed the new master cylinder so I would try bleeding the brakes again, maybe closing each bleed screw before the pedal is released each time.
    It can be a real PITA to get all the air out.
     
  3. txeye1

    txeye1 Member

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    Thanks for the fast reply....Yes...I did a bench bleed on the master cylinder..before the install....the first master cy...was leaking where the resv meets the master cyc and exchanged it and started over again..another question is are the bleeder valves suppose to be facing up or down on the front cal...the gm dealership saids down...but the all data shows up and in fact facing in the 1200 position on the front cals...
    any suggestions.
     
  4. Case 7230

    Case 7230 Senior Member

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    If the bleed screws are not at a high point on the caliper you will never get them bled.
    I have never come across bleed screws on calipers that were not at the top of the caliper when fitted to the truck.
     
  5. leolkfrm

    leolkfrm Full Member

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    do you have the wrong calipers?
     
  6. Case 7230

    Case 7230 Senior Member

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    Sounds like the LH caliper is on the pass side and the RH one on the drivers side.
     
  7. txeye1

    txeye1 Member

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    UPDATE:

    I have correct CALIPERS,tho I did locate a leak where two rear brake lines meet to connect...and replaced all four bleeder screws..Tighten it and attempted to bleed again. Expect, this time ...I placed long rubber hose to bleeder screw...ran it to a one quart jar with about 2" of clean brake fluid and flushed the entire system until it ran clear...it was black,also a small piece of rubber came out the right rear bleeder screw....Tons of air....I mean Tons.....I now have about 1/2 pedal...still needs more done....I am replacing the rear wheel cyl. for now.....Any Opionions.
     
  8. formulabruce

    formulabruce Senior Member

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    I would do the "double duty" as call it, have a person pressing brake pedal and use a mighty vac hand held as well. The abs unit can cause trouble getting all the air out.also this may fix any air left in the master cylinder,which cant get through the abs valves.
     
  9. busairman

    busairman New Member

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    when you're bleeding, do you have to hold open the "combination valve"? my manualsays you have to and a special tool will hold it open. i've tried this, but this only seems to dump fluid everywhere when bleeding. also it takes 3 people to bleed since i don't have the actual tool. just wondering if this is really neccessary.
    thanks for your thoughts!
     
  10. txeye1

    txeye1 Member

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    All is ok after bleeding the brakes for hours......I have never seen so much air in my life.....I took advantage of the sitvation and flush the system as well.....all air out and system is back to normal. \
    Thanks for all the help.
     

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