Brake issue
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New User
Joined: Mar 2009
Posts: 11
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From: Lake Stevens, WA
Brake issue
I have a brake issue with my '95 F250. I have replaced calipers, master cylinder and booster canister. My issue is that I don't get full braking as I think it should. I have bled the brakes myself as well as a mechanic friend has worked with me bleeding them. It almost seems as if the proportional valve has shifted but I am not getting a brake light indicator. The light comes on when starting the vehicle so I know the light is OK. I know there is a proper sequence to brake bleeding and have followed that sequence. I am about ready to take it to the dealer and have them diagnose and repair it but I don't want to second mortgage the house either. Any suggestions.
Fleet Mechanic
Joined: Feb 2007
Posts: 1,652
Likes: 79
From: Mooresville, NC
I have a brake issue with my '95 F250. I have replaced calipers, master cylinder and booster canister. My issue is that I don't get full braking as I think it should. I have bled the brakes myself as well as a mechanic friend has worked with me bleeding them. It almost seems as if the proportional valve has shifted but I am not getting a brake light indicator. The light comes on when starting the vehicle so I know the light is OK. I know there is a proper sequence to brake bleeding and have followed that sequence. I am about ready to take it to the dealer and have them diagnose and repair it but I don't want to second mortgage the house either. Any suggestions.
Is that new brake booster functioning properly?
With the engine "OFF", depress and release the brake pedal 4-5 times.
Depress the brake pedal firmly and start the engine.
If the pedal goes down slightly the brake booster is operating properly.
If the pedal does not go down slightly the brake booster is not assisting in brake operation. Verify vacuum supply to the booster.
Maintain pressure on brake pedal while turning "OFF" engine. The pedal should remain in the same position. If the pedal slowly slowly rises, the booster or vacuum check valve is leaking.
Verify the brake booster vacuum line is intact and installed properly. Verify that the vacuum check valve allows flow only towards the intake manifold, and not in reverse towards the booster.
Verify that engine vacuum is at least 17 in hg.
Thread Starter
|
New User
Joined: Mar 2009
Posts: 11
Likes: 0
From: Lake Stevens, WA
Is that new brake booster functioning properly?
With the engine "OFF", depress and release the brake pedal 4-5 times.
Depress the brake pedal firmly and start the engine.
If the pedal goes down slightly the brake booster is operating properly.
If the pedal does not go down slightly the brake booster is not assisting in brake operation. Verify vacuum supply to the booster.
Maintain pressure on brake pedal while turning "OFF" engine. The pedal should remain in the same position. If the pedal slowly slowly rises, the booster or vacuum check valve is leaking.
Verify the brake booster vacuum line is intact and installed properly. Verify that the vacuum check valve allows flow only towards the intake manifold, and not in reverse towards the booster.
Verify that engine vacuum is at least 17 in hg.
With the engine "OFF", depress and release the brake pedal 4-5 times.
Depress the brake pedal firmly and start the engine.
If the pedal goes down slightly the brake booster is operating properly.
If the pedal does not go down slightly the brake booster is not assisting in brake operation. Verify vacuum supply to the booster.
Maintain pressure on brake pedal while turning "OFF" engine. The pedal should remain in the same position. If the pedal slowly slowly rises, the booster or vacuum check valve is leaking.
Verify the brake booster vacuum line is intact and installed properly. Verify that the vacuum check valve allows flow only towards the intake manifold, and not in reverse towards the booster.
Verify that engine vacuum is at least 17 in hg.
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