Air in brakes

[Blaazer]

Anybody have any ideas here: after bleeding the brakes several times, brake light still stays on.

here is the situation.

a) car sat for a year - timing was off from a cam change.
b) power booster hose was disconnected when mechanic returned car.
c) checked brake light circuit, circuit is ok.
d) proportioning valve is ok.

Upon receiving car from mechanic, noticed my pedal was hard. Inspected the brakes. Badly corroded bolts, pads and bleeders. I decided to change the following

1. replaced all calipers
2. bled system - brake light stayed on
3. replaced master cyclinder
4. bled system - brake light stayed on
5. change lead gaskets
6. bled system - brake light stayed on

Now the pedal sinks to the floor

Here are the million $ questions, can a power booster become damaged from driving without its vacuum hose being connected?

Could the booster check valve be damaged?

Can brake fluid in a car stored for a year damage the booster?

If the booster / check valve is damaged, how can it be verified wether items are on or off the car?

Thanks

[Mikado14]

can a power booster become damaged from driving without its vacuum hose being connected?

I have never seen this, however, driving with this disconnected would not be advised. Secondly, would have a bodacious vacuum leak.

Could the booster check valve be damaged?

The booster check valve prevents the vacuum from being lost after you shut off the engine.

Can brake fluid in a car stored for a year damage the booster?

If you mean, can brake fluid damage the vacuum booster, yes, over time it can. But the source of the fluid would be from the Master Cylinder and you would have other worries first. Do you have brake fluid in the booster?

If the booster / check valve is damaged, how can it be verified wether items are on or off the car?

Not too sure what you are asking here.

If your pedal is goind to the floor, you have air in the system, provided that the Master cylinder is OK. Rebleed your system.

As far as the Brake Light being on, Is your emergency brake on? Is the switch on the Ebrake bad? Disconnect the wire and eliminate that potential until you have the brakes functioning.

[Fireplug]

Check e-brake pedal and make sure that it is not keeping the light on
Fireplug

[OverBoardProject]

There is a plunger type thing between the 2 brake resouvior's, designed to move over when 1 system runs out of fluid triggering the light on.

It probably needs moving over, which is done by getting a friend to step on the brakes, and cracking 1 of the brake lines leaving the master cylinder.. the re-tighten it.

Check the light, and if it's still on try the other brake hose.

The new master cylinder could be faulty too.

[Fireplug]

Ok let start over.
What year is it ? What engine? ABS? What body style?
What is the main problem ? And what have you done so far?
Fireplug

[busa_4]

when you replace a master cylinder you have to bench bleed it first otherwise you are going to get no pedal as there is air trapped into the master cylinder. since it is installed already you must fill the resevoir and have a friend pump the brake pedal a few times. once this is done, have your friend hold the pedal down while you loosen both lines on the master cylinder. you should see fluid coming out or u should hear air whistling out or both. repeat this step until you hear no more air escaping. after that then you will need to properly bleed the rest of the system. remember! bleed calipers from farthest to nearest.

[movin2stereo]

I heard that air in the abs system can be bitch to get it all out.Are you using a vacuum pump?

[Mikado14]

Where is the original poster of this thread?

[Blaazer]

Originally Posted by busa_4

when you replace a master cylinder you have to bench bleed it first otherwise you are going to get no pedal as there is air trapped into the master cylinder. since it is installed already you must fill the resevoir and have a friend pump the brake pedal a few times. once this is done, have your friend hold the pedal down while you loosen both lines on the master cylinder. you should see fluid coming out or u should hear air whistling out or both. repeat this step until you hear no more air escaping. after that then you will need to properly bleed the rest of the system. remember! bleed calipers from farthest to nearest.

Thanks. This was the one time I did not take bench bleeding seriously. I will from now on. To put all of this to rest, I have purchase a pressure bleeder.

[Blaazer]

Originally Posted by Blaazer

Thanks. This was the one time I did not take bench bleeding seriously. I will from now on. To put all of this to rest, I have purchase a pressure bleeder.

This is not abs, it is rwal.

[Blaazer]

Originally Posted by Fireplug

Ok let start over.
What year is it ? What engine? ABS? What body style?
What is the main problem ? And what have you done so far?
Fireplug

busa 4 hit it on the head. Just wanted to finish, I decided not to bench bleed.

[busa_4]

glad to help.