Whats Up With The Brakes?

[killerbp79]

After reading a lot of posts, you all know about the brake issues; spoungy pedal, intermitent pressure height....so on.

 

Everytime I brake the pedal is different causing me to either stop short, or almost hit whats in front of me...lol

 

What the heck is the fix?

[txab]

I'd look into the master cylinder for starters

[Draenor]

Have you visually inspected anything, or performed any test? This could be a few things. As Darral mentioned, check the booster. Inspect the fluid, check the pistons and calipers, bleed the brakes.

 

 

 

With the engine off, pump the brake pedal to remove any residual vacuum in the booster.

Hold pressure on the pedal while you start the engine. When the engine starts, the pedal should drop about a 1/4", this indicates that the booster is working properly.

 

Next

 

Run the engine a couple of minutes.

Turn the engine off and press the pedal several times slowly. The first pump should be fairly low. The second and third should become slightly firmer. This indicates an airtight booster

 

Next

 

Start the engine and press the brake pedal, then stop the engine with the pedal still pressed. If the pedal does not drop after holding the pressure on the pedal for 30 seconds, the booster is airtight.

 

If these fail inspect the check valve.

 

Disconnect the vacuum hose where it connects to the intake manifold. Do not disconnect the vacuum line from the booster. Air should not flow when pressure is applied, but should flow when suction is applied. If air flows in both directions or there is no air flow, the valve needs to be replaced.

 

Last

If the other test pass, next is to check for vacuum. Run the engine and see if there is vacuum comming from the engine at the hose before the cylinder.

[killerbp79]

Have you visually inspected anything, or performed any test? This could be a few things. As Darral mentioned, check the booster. Inspect the fluid, check the pistons and calipers, bleed the brakes.

 

 

 

With the engine off, pump the brake pedal to remove any residual vacuum in the booster.

Hold pressure on the pedal while you start the engine. When the engine starts, the pedal should drop about a 1/4", this indicates that the booster is working properly.

 

Next

 

Run the engine a couple of minutes.

Turn the engine off and press the pedal several times slowly. The first pump should be fairly low. The second and third should become slightly firmer. This indicates an airtight booster

 

Next

 

Start the engine and press the brake pedal, then stop the engine with the pedal still pressed. If the pedal does not drop after holding the pressure on the pedal for 30 seconds, the booster is airtight.

 

If these fail inspect the check valve.

 

Disconnect the vacuum hose where it connects to the intake manifold. Do not disconnect the vacuum line from the booster. Air should not flow when pressure is applied, but should flow when suction is applied. If air flows in both directions or there is no air flow, the valve needs to be replaced.

 

Last

If the other test pass, next is to check for vacuum. Run the engine and see if there is vacuum comming from the engine at the hose before the cylinder.

 

WOW, now that what I call a response!! Thanks I will perform these test today and get back to you all. Visually there are no leaks...TBC...

[killerbp79]

Ok the booster seems to be "airtight", Now how do I check for vacuum? What hose do i pull and how do I know its enough vacuum?

[Draenor]

Ok the booster seems to be "airtight", Now how do I check for vacuum? What hose do i pull and how do I know its enough vacuum?

Should be a hose comming out of the booster going to the engine(Intake Manifold). Unless you have a vacuum gauge, you not going to know. As long as you have vaccum you should be ok.

[Draenor]

WOW, now that what I call a response!!

Yeah,some of us have no real lives.

[killerbp79]

LMAO.....knowledge and comedy all in one huh. I can get a vacuum guage. So I pull the hose off the intake then stick the guage on it, right? what should the guage read at idle, and anything else I should check for?

[killerbp79]

anyone know what the vacuum guage should read?

[killerbp79]

did another walk around and noticed my abs wheel speed sensor just hangin there! that explains the abs light to me, but not the pressure issue, unless im missing somethng?? what does it do?

[Draenor]

anyone know what the vacuum guage should read?

Not sure. I never really hooked one up and cross checked the reading with anything. I just made sure I usually have good vacuum.

 

did another walk around and noticed my abs wheel speed sensor just hangin there! that explains the abs light to me, but not the pressure issue, unless im missing somethng?? what does it do?

That could be your problem. The pressure issue, does this occur at all times or only when you are actually stopping?

[killerbp79]

John,

The "pressues" issue is when im actually stopping and is intermittent(sp?). Sometimes the brakes are fine, then sometimes the pedal just goes almost to the floor...

 

I will check the vacuum in a little while and get back to you guys.

[killerbp79]

OK finally some pictures of the speed sensor.

 

Also I couldnt get the vacuum hose off the manifold, so i just took it off the booster, there is good vacuum sucking from the hose!

 

NEXT??? lol

[txab]

Have you performed tasks in post #3 yet?

[killerbp79]

Have you performed tasks in post #3 yet?

 

 

ya they all passed