The 1997 Chevy Blazer Brake Pedal Goes All the Way to the Floor

In 1969, Chevy introduced the Blazer. It was a topless vehicle in four wheel drive only. It wasn't until 1970 that a two-wheel drive was introduced, along with the GMC Jimmy. The 1997 Chevy Blazer was equipped with front disc brakes and rear drum brakes with ABS (an automated braking system) as standard equipment. Four wheel disc brakes were optional. Losing brakes completely, where the pedal travels to the floor, has only two general possibilities; lack of fluid due to a major line leak or a failed master cylinder. All Chevy's have what is called diagonal braking. This is a safety feature where one wheel on the front of the vehicle and one wheel on the opposite side in the rear are interconnected. This way, if a failure is experienced in one of the front or rear brakes, the opposite side will be unaffected and allow braking to remain even and effective despite the failure.

Instructions

Diagnosis

1

Open the hood and remove the cap on the brake master cylinder, located on the driver's side firewall attached to the round brake booster.

2

Check the level of the brake fluid.

3

If there is fluid in the master cylinder, the master cylinder is at fault and needs to be replaced. If there is no fluid in the master cylinder there is a leak in the system.

Master Cylinder

4

Loosen, but do not remove the two brake line connections on the master cylinder, using the line wrench. Unplug the low-brake-pressure switch on the side of the master cylinder. Remove the two 15 mm nuts securing the master cylinder to the brake booster, using a socket. Continue to remove the two brake line connections on the master cylinder, using the line wrench.

5

Remove the master cylinder from the truck. Lay the new master cylinder on a flat surface. Remove the two plastic brake bleeder lines that accompany the new master cylinder. Thread them clockwise in each brake line hole on the side of the master. Fill the master cylinder with brake fluid.

6

Hold the ends of the bleeder lines in the master cylinder reservoir so they are submerged in the brake fluid. Keep them submerged as the master cylinder is being bled so no air gets into the master.

7

Push the master cylinder rod all the way in and let it out, using the Phillips screwdriver, until all the air is expelled into the fluid in the reservoir. Hold the two brake bleeder lines in the reservoir so they don't leak onto the trucks surface and install the master cylinder onto the studs on the power brake booster. Install the two 15 mm nuts and tighten with a socket.

8

Remove one brake bleeder line at a time and quickly thread the brake line into the master cylinder by hand turning the nut clockwise. Wipe off any excess brake fluid so it doesn't get on the paint. Tighten the brake lines with the line wrenches.

9

Fill the master cylinder to the correct level and install the cap. Plug in the low brake pressure warning switch wire.

Line Leak Repair

10

Lift the truck with the floor jack and place jack stands under the truck's frame. Lower the truck on the jack stands so they are bearing the weight. Search for the fluid leak. Measure the length of the brake line and purchase a brake line two inches longer.

11

Soak the fittings with rust penetrant. Remove the brake line fittings using the line wrenches. Bend the new brake line using the bending tool so that it closely matches the one removed. Install the brake line and tighten the fittings securely.

12

Bleed the brakes one at a time. Start with the right rear brake bleeder screw. Open the screw and have a helper depress the brake pedal and hold it to the floor. Close the bleeder screw before he raises the brake pedal so no air is sucked into the system. Once the pedal is up, loosen the bleeder screw again and repeat this procedure until all air is expelled and the fluid is clear and without bubbles.

13

Move to the left rear brake and repeat the procedure. Keep checking the brake fluid in the master cylinder reservoir so it doesn't run out of fluid and suck air into the master.

Rear Wheel Cylinders

14

Check the rear wheel cylinders if there was no leak found in the brake lines. Look at the inside back of the brake backing plate. In other words, the leak will be seen on the inside of the wheels --- they will be wet with fluid with a leak this big. Lift the rear of the truck with the floor jack and support it with jack stands.

15

Remove the rear tires using a lug wrench to loosen the lug nuts. Remove the rear brake drum by pulling it off. Apply the emergency brake (parking brake) as far as it will go. This will spread the brake shoes away from the wheel cylinder making it easier to replace.

16

Remove the brake line fitting on the back of the wheel cylinder using a line wrench. Remove the two small bolts securing the wheel cylinder to the brake backing plate. Remove the wheel cylinder and install a new one.

17

Install the brake line while the wheel cylinder can be moved around to align the threads. Loosely tighten the fitting. Install the two bolts securing the wheel cylinder and tighten them with a socket.

18

Tighten the brake line with a line wrench. Open the wheel cylinder bleeder screw and allow it to remain open until brake fluid comes out in a steady stream. At this point close and tighten the bleeder screw. Check the master cylinder reservoir for brake fluid and fill as necessary. Bleed the opposite side in the same manner. Lower the truck off the jack stands.