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I talked to some guru's this morning about my brake pedal problem and here's what they had to say:
Volvo Guru Says:
He suspects either the MC is bad or the brake booster isn't pushing the MC piston in far enough to make pressure. He said to unbolt the MC again and check the booster rod to make sure it meets spec. He doesn't suspect the distribution block because it isn't leaking. I asked him about clamping off the rubber brake lines (the Foster approach) and he said they have a wire mesh inside and that clamping them should pose no problems.
Master Cylinder Factory Guru Says:
He suggested that I reinstall the plastic plugs into the master cylinder again and bleed it. Then push the brake pedal with the engine off and on to check the booster and the MC. He said if I have a hard pedal then, the MC is not at fault.
I did that test when I installed the new MC and I did have a hard pedal.
He also suggested that I gravity bleed the system instead of using vacuum or pressure bleed methods. He said that on GM trucks, they could pressure or vacuum bleed a gallon of fluid throught the system and still have no pedal until the system was gravity bled. He has also seen cases where the calipers have to be removed and rotated with the pistons blocked to "burp" the calipers.
Anyone ever heard of doing that on a Volvo?
So here's my plan for tonight after work:
1)Unbolt the MC from the booster and check the booster rod.
2)Run the dead head test again on the MC & Booster
3)Gravity bleed the two rear calipers
4)Bleed the system again the old fashion way using the brake pedal to move the fluid out through the bleeders (if my wife still wants to help me).
5)Try using the Foster approach to isolate the problem area.
6)Attempt one last fix just to make sure I've tried everything known to man.
7)Put wheels back on, jack it up, remove jack stands and lower car to ground.
8)If brake pedal is hard - I'll be extremely happy.
9)If brake pedal is soft - Call tow truck and leave my credit card on the dash and hope it doesn't hurt too bad when they ream my a$$ at the repair shop.
DeWayne
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