Serious Brake Promblems

I have a 88' cherokee with brake promblems. When I turn the steering wheel while driving the brake pedal goes all the way down, with no resistince. I have to pump it twice before it starts to stop, only happens when I turn.Also, when I'm at high speeds the left tire seems to shake alot, and the brakes pulsate and pulls the jeep to the side. I have bled the brakes but does nothing.

Check brake fluid....is it low? If so I would be looking for cracks in the front brake hoses. Turn the wheels all the way to the side, and examine the hoses closely. Even if only one side is cracked, it's best to replace both sides at once.

Your shaking/vibrating.....first thing is to get the tire(s) balanced. Then you may want to look at having your rotors turned.