Brakes still spongy after bleeding

[beardeddummy]

I've heard something about cycling the abs but don't know how. I'm tired of this what do I do?

97 k1500 5.7

 

[michael hurd]

There are a few things you can do. Recommended to have the system bleed procedure done with a Tech 2 scanner.

If you don't have access to one, you can go for a ride down a gravel or snow covered road and lock the brakes, forcing the ABS system to pulse the brakes. ( with the ABS connected, assuming the wiring and wheel speed sensors are good in the bearings )

I have also read you can block up the vehicle so the rear tires are off the ground in 2wd. Put the vehicle in gear and then accelerate up to highway speed spinning the rear tires then jam on the brakes. The ABS system should kick in, as it thinks the front tires are skidding. ( I have not tried this method )

Repeat the conventional bleeding after each successive attempt at pulsing the abs module. Pump slowly, waiting ~10 seconds between each pump, then hold pressure and have someone crack the bleeder at each wheel.

 

[twomanymontes]

Yes, What Michael said. I have done the "spinning the rear wheels in the air" Trick a couple times. But try really slamming on the brakes when you do it. Make sure the truck's front wheels are blocked. Then bleed it again.

The gravel/snowy road idea seems a tad unsafe to me.

 

[df2x4]

X3. When in doubt, just take it to a shop with a Tech 2 (or equivalent) scan tool that can cycle the ABS during bleeding.

 

[beardeddummy]

I just really can't afford that right now

 

[michael hurd]

If you can't afford to take it to someone, jack it up and block up the rear axle. Spin the tires and step on the pedal, activating the ABS module. Bleed after that. Repeat the abs activation, bleed. Continue at all 4 corners until you have solid clean fluid and a good pedal.

I had solid fluid in mine, but kind of spongy pedal, in the end I had used 4 liters of fluid to bleed, but that was taking it for a drive, then locking the brakes, bleed, repeat.

Should have added, the rear brakes need to be adjusted up tight before proceeding to this...

 

[beardeddummy]

That's what I'll be doing since my jack and Jack stand were stolen

 

[Jrgunn5150]

Don't just lock the pedal, go nuts, pump the **** out of it, lock it twenty seven times, get it all out of there and effed up, then bleed. Rinse and repeat until you have your pedal back.

Clearly, be safe, don't do it towards the playground.

 

[beardeddummy]

I was able to gravity bleed them and I got my brakes back

 

[Slime]

I read on another forum about bleeding the ABS unit. Guy had the same issue. There is a valve on the back side of the unit that he bled. I haven't tried it because I need to replace some lines, but...thoughts?