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GM has an unusual master cylinder design on their front-wheel-drive cars. I think this includes an '89 model. There is a valve in it that will move to block off two ports when there is unequal pressure in the two hydraulic systems. That is a nice feature if you spring a leak because it will prevent brake fluid from being lost, but if you bleed the system improperly it will also trip that valve. Most front-wheel-drive cars use a "split-diagonal" hydraulic system meaning the left front and the right rear brake are on the same system, and the right front and left rear are on the other. They aren't split front and rear like on older cars and trucks. Due to design changes in "scrub radius", a non-adjustable alignment angle, you will not have a brake pull when one front brake isn't working.
Pedal-bleeding on the car, with a helper, and bench-bleeding the master cylinder will trip that valve. If that happened during bench-bleeding, there could be air still in that part of the master cylinder and there's no way to get it out until that valve is reset. The only way I've found that always works is to go to one of the wheels that isn't flowing any brake fluid when you open the bleeder screw, and give it a very short, quick burst of compressed air, then let it gravity-bleed.
With any master cylinder you should never run the brake pedal more than half way to the floor to avoid damaging the lip seals on the crud and corrosion that build up in the bores where the pistons don't normally travel. With the GM master cylinders you can also avoid tripping that valve by not pushing the pedal more than half way.
The first thing is to verify brake fluid is flowing from both front calipers. I suspect you'll find no fluid flows from one of them and you'll have to reset the valve with compressed air. Once you reset that valve, crack open the cover on the master cylinder reservoir so the fluid can run down freely, and open both front bleeder screws, then wait for the air bubbles to stop showing up. At that point, close the bleeder screws, push the brake pedal about one quarter way down very slowly, wait a few seconds, then let it release quickly. That will push brake fluid down, air bubbles will float back up, and when the pedal is released any air bubbles will wash back up into the reservoir. Do that multiple times until the pedal starts to feel more solid. Now you can continue to bleed at the wheels if it is still necessary.
Thursday, September 19th, 2013 AT 1:20 PM
