How to change brake booster - 1994 Pontiac Trans Sport

Question edited for clarity, wrong type of brake/break.

If you brakes have ABS, you have to bleed the brakes from the caliper up to the master cylinder using a pressure bleeder. It also works better on normal brakes because it pushes the air upwards which is its natural way, air rises in liquid.

Check rear of Master Cylinder--If wet likely Master Cylinder Leaking and Booster Damaged. They Should be replaced as a mated pair. (for warranty) and brake lines removed and system bled.

I had my power brake booster go bad and I replaced mine as well as bleed the brakes that when I went and tried them out 'I slammed on my breaks early before getting to close to the light' that my car left skid marks all over that road because the brakes worked like power brakes should and yours sound like your booster was installed wrong or the pads are bad or you didn't bleed all the air out of the line. Your problem you described was like it felt before I replace brake booster ie lousy non power brakes when I had power brakes.

How did you bleed your brakes or did you even do that? their should be a little nipple on your calipers or even the brake booster to bleed the system.

when you feel very hard to push the brake pedal, then must be problem of brake boosters. you can try to change a new one brake booster ,we supply all kinds of brake boosters ( vacuum brake boosters), toyota brake booster, Nissan brake booster, chevrolet brake booster etc, feel free to ask any questions. www.fiverhope.com

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Remove only the two nuts that secure the master-cyl. to the booster NOT THE FLUID LINES and tie the master cylinder carefully out of the way.Then remove the four nuts under the dash that secure the booster to the fire wall.Not forgetting the booster push-rod connection to the brake pedal.Remove the clip and the pin and now the booster should be free to come out.There are torque specs. for tightening the nuts when replacing if you have a torque wrench.Refer to Haynes manual from auto shop
Also I think the brake booster push-rod is adjusted at the factory but if it isn't it may need adjusting otherwise you could find youre getting overheating brakes after the installation.

Click here Jeremy to see how to replace brake booster.

from autozone.com:

1. Disconnect the negative battery cable.
2. Apply the parking brake.
3. Unplug all necessary electrical connections.
4. Remove the master cylinder from the booster and pull it off the studs, CAREFULLY! It is not necessary to disconnect the brake lines.
5. Disconnect the vacuum hose from the check valve.
6. If necessary, remove the brake light switch.
7. Disconnect the booster pushrod at the brake pedal.
8. Remove the booster mounting nuts, located on the inside of the firewall.

Fig. Fig. 1: Vacuum booster mounting

1. Lift off the booster and remove the gasket.

To install:

1. Install the booster with a new gasket.
2. Tighten the booster mounting nuts to 21 ft. lbs. (29 Nm) on all except 1996-98 models. On 1996-98 models, tighten the nuts to 26 ft. lbs. (36 Nm).
3. Install all remaining components.

Pretty simple repair.I even did this alone.
DO NOT disconnect the brake lines unless you are changing the master cylinder out with it. Unbolt the master cylinder and move it forward slightly. From inside the truck,unbolt the brake pedal from the rod, leave the pedal hanging. Remove the 4 bolts at the firewall that retain the booster.From outside the truck reach in and draw the old booster out.You may have to move the master cylinder up or down to clear the booster.
The rod to the brake pedal will come out with the booster,make sure you put it back on the new one.

Reverse to install.

good luck
Dave