1991 buick park avenue brake problems got bleed the brakes on the drivers side front and rear not a problem but the passenger side front cant get the air out keeps spitting fluid and have use a half b

You do not bleed brakes in an "X" pattern. You start bleeding at the wheel furthest from the master cylinder. Once that wheel is bled, move to the next furthest away from the master cylinder and so forth. Doing it in and "X" pattern would leave air in the lines.

Right rear first, do with engine running. LF next. left rear to right front. you may need to manually reset the proportional valve located under master cylinder. your brake lines go to this first before heading to the wheels, one side will have a rubber protector on it push it in to reset it.

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Are there two brake fluid reservoirs? And are both full? This would be a split-diagonal brake system-front driver and rear passenger are one brake system. Front passenger and rear driver are the other system. You have the one system working-the front passenger and rear driver side works. You will have to keep bleeding the rear passenger side and the front driver side-always start farthest from the master cylinder, but if that wheel just won't bleed air out, make sure the driver front is working and bleeds good. If all else fails, there are pressure bleeder kits available, I don't know the cost, but they work great. They are also a one man bleeding job, as I understand.

Hi Chris, The brake system is basically very simple. If you have duel braking on your vehicle, the usual method is having two brakes operate on the front with for example the left rear and the other system will also operate two front and the right rear. This type of system will have two calipers on each of the front wheels. The tandem system works in a slightly different way, having the forward part of the cylinder pressurizing the rear brakes and the rear part of the cylinder pressurizing the front. I think under the circumstances you are describing, I would have a friend sit inside and pump the brakes repeatedly until the system becomes pressurized (maybe twenty thirty times of pumping the brake pedal) and then ask him or her to keep it pushed firmly down until you find out where its leaking. The amount of brake fluid you report having been sed would indecate a severe leakage. Check the lower parts of the rear wheels for signs of leaking wheel cylinders and then dito for the front wheels. Any signs of wetness at these areas and along the brake system (the plumbing or pipe work) will indicate where the leakage is. If you cannot identify a wheel which is leaking, carefully inspect around and blow the master cylinder and if this no sign go along the fluid lines, taking special note of where the damaged pipe was repaired. If there is a blockage in the line, air may be trapped at that point causing difficulty in pressurizing. Once the place of leakage has been identified it must be attended to before bleeding the system. When bleeding, begin with the wheel furthest from the master cylinder, and work your way back to the master cylinder one wheel at a time, until you reach the closest.Keep in mind that you may find it required to pump the pedal many many times before opening the bleed nipple.Regards John

Yep need to know weather it is drum brakes or disc brakes.

unless the system was open there was no need to bleed the system. the Master Cylinder and the ABS unit are 2 different things. you should be able to bleed it like any other car. fill up the M/C and open the right rear bleeder, put a clear hose onto the bleeder, then you can see air come through. put the hose in a clean bottle and pump it until you see air come through, then a few more pumps, do this at each wheel. if all air is out and the pedal is not firm , the m/c may be bad.

this sounds like your master cylinder has gone out, Located on the fire wall on the drivers side of the car ,, if your fluid level is good, and you detect no fluid leaks at the wheel cylinders, this is the most likely problem

What this sounds like is either one of two things. A, there is air in your brake lines and they need to be bled, or you have a bad master cylinder and it needs to be changed. The easiest way to tell if it is the master cylinder is to first bleed the brakes, starting at the passenger rear, then the drivers rear, then the passenger front and finally the drivers front. Once you have done this, you should have a full pedal and if it is the master cylinder, it will only take a couple of times of pressing the brake pedal and it will be spongy again. If this is the case, then the master cylinder needs to be replaced.

Yes, you have to pre bleed the M/C. After market parts stores sell a kit that allows you to bleed it easily....It is difficult to get air to go downhill.

after prebleeding M/C, do not let it run dry while bleeding the brakes.

check the vacumn line coming out of the firewall on the passenger side. it is in the wiring harness coming from inside of the car. very common to brake with age. dry rott. best of luck