Another brake bleeding question

[mike_dmt]

So, I had a caliper sticking, and replaced it. Turned the warped rotor, and changed the pads on the good side too, just for good measure. Went to bleed the system, and like many of the posts I've looked through I've got the same problem of a low/spongy pedal. I went through about a quart of fluid thinking it was air in the lines.

I called some mechanic friends as well as a brake shop, who informed me of the quick take up MC on these vehicles. I let the system gravity bleed for about a half hour, and then bled again with his recommendations, which isn't the pump pump pump technique, but a 15 second interval between single pump then bleed style, with the same result... low/spongy pedal, which wasn't the case before.

So after an hour of looking through other posts on here, I believe the ABS needs bled. Can anyone tell me how to do this? I can't believe it's this complicated, I've done this stuff for a while now....

[MT-2500]

Originally Posted by mike_dmt

So, I had a caliper sticking, and replaced it. Turned the warped rotor, and changed the pads on the good side too, just for good measure. Went to bleed the system, and like many of the posts I've looked through I've got the same problem of a low/spongy pedal. I went through about a quart of fluid thinking it was air in the lines.

I called some mechanic friends as well as a brake shop, who informed me of the quick take up MC on these vehicles. I let the system gravity bleed for about a half hour, and then bled again with his recommendations, which isn't the pump pump pump technique, but a 15 second interval between single pump then bleed style, with the same result... low/spongy pedal, which wasn't the case before.

So after an hour of looking through other posts on here, I believe the ABS needs bled. Can anyone tell me how to do this? I can't believe it's this complicated, I've done this stuff for a while now....

Same post in another foprum.
2 post gets 2 confusing answers.
Only use one post.
Delete the other one.

[j cAT]

what is the vehicle details ? what caliper ? did you drain the res. of brake fluid...that air could get into the abs...? did you quickly replace cal...or let the fluid leak out when you had all these parts replaced worked on ?

you feel that this should not be that involved , and you are correct ! If you did this improperly you WILL have this problem...

I suspect you have an air bubble in the line....when ever bleeding I do not pump brake pedal quicly....and never all the way to the floor...also you need an asistant to do this ...unless you have special equiptment...also never allow the res. to go dry...

when bleeding the calipers you use a clear piece of tubing with the tubing pointing up 6 inches then down into a container you watch for bubbles....you continue to pump,bleed a little , pump, bleed a little until the fluid is clear and no bubbles....front first then rear...and refill res. after each caliper..bleed...

I just blew out a line on my silverado directly under the driver pan ...lost a lot of fluid...but with bleeding out the complete system , as descibed here when line was replaced all is perfect...

[GMMerlin]

Sometimes when you bleed the brakes on these vehicles you will get a spongy pedal, but you will get no air out of the lines.
Find a safe place where you can perform a couple ABS activated stops, you will notice a change in pedal feel.

[mike_dmt]

Sorry for the late response... 98 Tahoe, 5.7, 4WD, lots and lots of miles.

I will answer questions to the best of my memory. Drivers front caliper is the one that was replaced. Yes, I did probably let it drain down a bit in between the new one, but there was still fluid in the resivoir.

Let it gravity bleed for a half hour or so... Still spongy.

Haven't tried the abs stops yet but will do so in the morning.

What scanner will let me bleed the ABS?

[MT-2500]

Any good ABS capable scanner should have it built into it.
Snap on or GM tech scanners are two .

[j cAT]

Originally Posted by mike_dmt

Sorry for the late response... 98 Tahoe, 5.7, 4WD, lots and lots of miles.

I will answer questions to the best of my memory. Drivers front caliper is the one that was replaced. Yes, I did probably let it drain down a bit in between the new one, but there was still fluid in the resivoir.

Let it gravity bleed for a half hour or so... Still spongy.

Haven't tried the abs stops yet but will do so in the morning.

What scanner will let me bleed the ABS?

well this expains your spongy pedal.....you must use an asistant to slowly pump the brake pedal to bleed these BOTH front calipers....as this is how to drive out the air ..use the method I previously descibed...

hose must be up so no air can enter when fitting open...the brakes will return to normal when the air is removed..

you must remove the air as this is how the fluid destroys the internal brake componets.....contamnation/corrosion...that ABS is expensive...

since the res. did not go dry I would think with just a spongy pedal this method should work ....

[mike_dmt]

Thanks a ton. I tried to make a few ABS stops, with no change, unfortunately.

I will try and bleed the system again tomorrow.