Soft brake pedal

Tiny
JOSHUASMITH
  • MEMBER
  • 2002 CHEVROLET BLAZER
  • 4.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 155,000 MILES
Was wondering how come when I pump my brakes up with engine off why does the pedal get hard, but I still can push it to the floor when bleeding brakes. I noticed in my other car and a buddy's car that when I pumped the brakes up with engine off the pedal gets hard and no matter how much pressure u push on pedal it doesn’t move. Mine does. What would cause this on my car?
Tuesday, August 13th, 2019 AT 4:30 AM

3 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

It should go to the floor when bleeding the brakes. That is normal.

What is your exact issue?

Roy
Was this
answer
helpful?
Yes
No
-1
Friday, March 19th, 2021 AT 11:55 AM
Tiny
BIGJOSH
  • MEMBER
  • 2 POSTS
My problem is no brake pedal. Put new master cylinder and front calibers plus checked the vacuum booster valve. Still no brake pedal. Can’t seem to find any leaks. Still don’t have brake pressure in my pedal. I was talking about with engine off and pumping up my brake pedal it gets hard but it does hold. I know it will go down when bleeding.
Was this
answer
helpful?
Yes
No
Friday, March 19th, 2021 AT 11:55 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Okay, thanks.

You need to do the automated brake procedure for the ABS module. You will need a scan tool for this procedure to get rid of all the air. The procedure is below.

Roy

Important:
Use the two-person bleed procedure under the following conditions:
- Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
- Air is trapped in the valve body.
Do not drive the vehicle until the brake pedal feels firm.
- Do not reuse brake fluid that is used during bleeding.
- Use the vacuum, the pressure and the gravity bleeding procedures only for base brake bleeding.

1. Raise the vehicle in order to access the system bleed screws.
2. Bleed the system at the right rear wheel first.
3. Install a clear hose on the bleed screw.
4. Immerse the opposite end of the hose into a container partially filled with clean DOT 3 brake fluid.
5. Open the bleed screw 1/2 to 1 full turn.
6. Slowly depress the brake pedal. While the pedal is depressed to its full extent, tighten the bleed screw.
7. Release the brake pedal and wait 10-15 seconds for the master cylinder pistons to return to the home position.
8. Repeat the previous steps for the remaining wheels. The brake fluid which is present at each bleed screw should be clean and free of air.
9. This procedure may use more than a pint of fluid per wheel. Check the master cylinder fluid level every four to six strokes of the brake pedal in order to avoid running the system dry.
10. Press the brake pedal firmly and run the Scan Tool Automated Bleed Procedure. Release the brake pedal between each test.
11. Bleed all four wheels again using Steps 3-9.
This will remove the remaining air from the brake system.
12. Evaluate the feel of the brake pedal before attempting to drive the vehicle.
13. Bleed the system as many times as necessary in order to obtain the appropriate feel of the pedal.
Was this
answer
helpful?
Yes
No
Friday, March 19th, 2021 AT 11:55 AM

Please login or register to post a reply.

Sponsored links