Hi guys,

About three weeks ago I purchased a 2000 2DR with the ZR2 suspension package locally. I got it for a great price and needed something 4WD.

When I bought the truck it had no ABS light on, however when applying the brakes it would trip and the pedal would freak a little bit.

The next day I bought an aftermarket wheel bearing for the RF side. I bought the wheel bearing because no one local had JUST the speed sensor. So, I removed the speed sensor from the aftermarket wheel bearing and installed it in the current wheel bearing on the truck.

After I installed the wheel speed sensor I also installed new calipers pads and rotors on the rear and bled all brakes starting at the right rear, left rear, right front, left front.

Took the truck out, set the pads to the rotors, and the ABS light came on.

The truck hands down brakes much better and the pedal is a bit more firm now.

Do I need to bleed the ABS system separate from the calipers? I have never bled an ABS system and not familiar with these trucks.

Or the other thing I'm thinking, is that maybe the LF wheel speed sensor needs to be replaced? The ABS system does not act wonky anymore though. The pedal may be a bit spongy, that's it.

Regardless, I don't want any lights on.

I scanned the truck with an OBDII scanner and the following codes are in HISTORY:

B0269
Excessive dump time

B0265
Electronic Brake Control Module motor relay circuit

B0281
Stop lamp switch circuit

B0222
Right front wheel speed signal missing

B0226
Left front wheel speed signal missing

Any help appreciated here guys. Thanks.

 

I'm pretty sure you have to put the ABS on a vacuum or special machine, you can't just bleed them.

 

The abs systems on our older blazers and jimmys are very prone to problems.They push back on the pedal at just the wrong time for no real reason.You can spend big bucks having the system diagnosed and parts replaced,or you can simply disable the abs side of the system by unplugging the electrical connectors under the abs unit and placing a piece of tape over the led bulb in the dash.You will not have abs,but the brakes work great without it.

 

Thanks for your replies guys. I have never vacuum bled an ABS system but from some light searching it seems like there's a separate way to bleed the ABS system. I'm going to look into that and see if that will fix my problem.

In the meantime, I cleared all the codes from history and will re-run the OBDII scanner and see what faults come up now because the ABS light remains on and constant.

If it ends up being a mess to track down, the light will stay on. Because in my opinion the truck brakes fine after replacing the speed sensor, rear pads and rotors, and bleeding the system.

 

I had a '94 with the ABS light. The problem is you need a TechII scanner to bleed the ABS, if I remember correctly. I've seen the prices from $600.00 to about $3,000.00. If I were you, I would just take it to a GM dealer and have them bleed the ABS. And that comes from someone with a pretty decent "weekend warrior" shop set up that hates to takes my vehicles to a shop.

I can't think of all the details off-hand, but it has something to do with the controlling and shifting the "flaps" (my word) while the bleeding is being done. I spent many hours trying to figure out how I could do the bleed without have the right scanner. My conclusion is there is no way you can.

Also, I do remember in all the research I was doing with this, there is something you don't want to do when replacing or bleeding your brakes, or it can cause the problem with the ABS. I just don't remember what it was specifically.

 

You shouldnt have to bleed the abs system unless the brake fluid drained completely past the abs module. When you installed the wheel speed sensors did you clean the surface so it would sit flush? If it isn't pushed in close enough it can give flase readings and cause the abs light to stay on and or activate abs at low speeds. The actual abs bleed literaly takes 2 minutes to do with a tech 2 but the dealer charges a foturne for this procedure.

 

That's what it was...I knew there was something that you had to make sure you didn't do. I bought the '94 with the light on....never did get it bled before I got rid of it, so I have no idea of the cost.

 

To the best of my knowledge the fluid was never drained past the ABS module.

What I am thinking though is that the sensor is not a 100% fit for the current wheel bearing that is on the truck. When I installed it, it was not sitting completely flush against the hub. From looking at it, it seems the current sensor is a tiny bit taller than OEM. I tightened it down as good as I could without breaking the plastic, and was concerned that it would trip the ABS light. I forgot about that.

I guess I will have to see the price on an OEM sensor, and also want to re-scan the truck and see what codes come up now.