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Need help bleeding brakes after new lines and master cylinder
Hummer H2For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.
but would a bad brake booster engage brakes and then just sink to floor? i checked to see if any leaks anywhere but dont see anything evident, but still seem to be getting air
Mine does the opposite. The pedal gets tighter but when I start it it goes to floor. I took for test drive and it responds to brakes but once it brakes, the pedal gets soft and sinks to the floor.
I've tried the tube in a bootle with oil, I tried a compressed air vacuum bleeding system, but non work for me. Could it be a bad master cylinder??
Besides the tech2 unit, anyone had any success auto bleeding with autre or Foxwell??
Make sure you have enough fluid in power steering pump reservoir but it kinda sounds like a bad hydro boost unit BUT nothing is going to work unit you get the auto bleed to work. Can you rent the tool from a local parts house? I don't remember what brand I used but I rented it.
you can put a 14 psi vacuum on your master cylinder resivour to see if any air bubbles come up out of it.
i have had bad master cylinders before on other vehicles. on mine it was a sinking pedal till it reached the floor. at stop lights if held long enough the car would start creeping and i would have to pump the pedal again. i do not know if thats what your experiencing.
This isn't rocket science. You have air in the system, and need to remove all the air, for a proper working hydraulic system!
First, replace the left rear caliper and make sure the new caliper has the bleeder at the TOP!
Next, check over all your fittings to make sure they are tight and not sucking air.
Then start by bleeding the master cylinder, easy to do with an assistant to slowly depress brake pedal(NEVER PUMP, AND NEVER ALLOW PEDAL TO GO TOO LOW OR YOU WILL BLOW THE REAR SEAL), open fitting, allow fluid/air out for a second or 2, close fitting. Repeat as many times as needed until no air comes from the master cylinder on either line.
Next, open bleeders at all 4 wheels and allow to gravity bleed. Wait for it, and close each fitting when you see fluid coming out without air.
All that is left, is to pressure bleed each wheel, starting from the furthest away from the master and work your way to the closest. (LHD: RR LR RF LF)
Simple technique with an assistant, depress pedal, open bleeder for a second or 2, close bleeder. Repeat until you don't see air bubbles at any wheel. Done.
BTW, make sure to keep the master full of fluid during the bleeding process.
Thanks for all the help guys. I was able to get it a little better but still goes low on the floor but maybe that’s normal on the h2?? How low should the brake pedal go on a properly bled system?
No less than half, normal pedal height. Get yourself a tape measure and measure travel. Another thing to do is raise all 4 wheels off the ground and depress the brake pedal, while holding with an assistant or a prop, go to each wheel and see if any spin.
As hummerz advises it's not normal, as a reference, I can stop my H2 with my finger within 2" of travel (just tried it)
Wow, that's some talent you have there. All you have to do, is measure pedal height (PARKED), then push the pedal down with your foot, and measure, then start up and repeat, should always be under 50% travel. e.g.: normal pedal height: 7" bottom pedal to the floor board/firewall, should not travel below 3-1/2".
All you have to do, is measure pedal height (PARKED), then push the pedal down with your foot, and measure, then start up and repeat, should always be under 50% travel. e.g.: normal pedal height: 7" bottom pedal to the floor board/firewall, should not travel below 3-1/2". 