loss of power brakes
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loss of power brakes
new to the forums..
'01 2500 Quad 4x4 5spd - bone stock 41,000 miles
lost power assist brakes today, "ABS" & "BRAKE" warning lights illuminated, never lost power assist steering...
topped of p/s pump resevior, cycled the racked back and forth, cycled the key on & off a couple of times, lights did not come back on yet pedal is still spongy.
Any thoughts? is the booster starting to fail or is it the master cylinder ?
'01 2500 Quad 4x4 5spd - bone stock 41,000 miles
lost power assist brakes today, "ABS" & "BRAKE" warning lights illuminated, never lost power assist steering...
topped of p/s pump resevior, cycled the racked back and forth, cycled the key on & off a couple of times, lights did not come back on yet pedal is still spongy.
Any thoughts? is the booster starting to fail or is it the master cylinder ?
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Joined: Jul 2002
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Use a brake scanner and read the codes. These systems have a pretty good set of error codes once a warning light is set, and that will save you a ton of money instead of throwing parts at the system.
Spongy pedal is air in the system. So it needs to be bled.
If by some fluke you cleared the codes, do a very careful bleed process and make sure the air is out of the system before you do anything else. The first thing to do on a full ABS system is to fill the master cylinder and then bleed in the following order:
Master cylinder, rear anti-lock valve, combination valve, front anti-lock valve, left rear wheel, right rear wheel, right front wheel, and then the left front wheel.
The anti-lock valves will bleed from gravity, but do them one at a time. The combination valve will also bleed from gravity, but do the sides in the same order as the anti-lock valves.
Once you have the valves bled, you will pressure bleed the individual wheel lines. Do not pump it up and slam it to the floor! What you want to do is pump slowly to build pressure, then crack the bleeder and follow the pedal to the floor. When it is on the floor, close the bleeder valve and then let the pedal come up by itself. LET IT STAND AT LEAST 15 SECONDS BEFORE PUMPING IT UP SLOWLY, AGAIN. If you jump right on the pedal and try to pump and dump like on the old non-ABS systems you will kill your ABS valves. TAKE YOUR TIME.
The much preferred method is to use a power bleeder, but if you are young enough and have the patience, the above method also works as long as you take your time and do not rush it.
Spongy pedal is air in the system. So it needs to be bled.
If by some fluke you cleared the codes, do a very careful bleed process and make sure the air is out of the system before you do anything else. The first thing to do on a full ABS system is to fill the master cylinder and then bleed in the following order:
Master cylinder, rear anti-lock valve, combination valve, front anti-lock valve, left rear wheel, right rear wheel, right front wheel, and then the left front wheel.
The anti-lock valves will bleed from gravity, but do them one at a time. The combination valve will also bleed from gravity, but do the sides in the same order as the anti-lock valves.
Once you have the valves bled, you will pressure bleed the individual wheel lines. Do not pump it up and slam it to the floor! What you want to do is pump slowly to build pressure, then crack the bleeder and follow the pedal to the floor. When it is on the floor, close the bleeder valve and then let the pedal come up by itself. LET IT STAND AT LEAST 15 SECONDS BEFORE PUMPING IT UP SLOWLY, AGAIN. If you jump right on the pedal and try to pump and dump like on the old non-ABS systems you will kill your ABS valves. TAKE YOUR TIME.
The much preferred method is to use a power bleeder, but if you are young enough and have the patience, the above method also works as long as you take your time and do not rush it.
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