04 Chevy ABS Problem

[Shane T]

ABS engages as you slowly pull up to a stop. First time it happened I thought I was going to hit the vehicle in front of me. Anyone know why? Can this be diagnoised without a scan tool?

 

[Contemporary Carpet Clean]

one of your ABS brake sensors is no good. My Navigator did the same thing. My mechanic had to use a scanner because if you have 4 wheel abs brakes you might have a hard time knowing which one it is. Sometimes you have to replace the hub assembly or you can just replace the sensor. Sometimes the hub assembly (bearings) is connected to the abs sensor. If you just try to replace the sensor sometimes it might not work because the seal on the hub assembly goes bad letting water and weather in which is why the sensor goes bad. Sounds like to me one of the front ones is going bad. Most of your braking power is from the front. If it felt like you were going to hit something and couldnt stop....i would say a front sensor is bad more so than a rear.

 

[Jimmy L]

I just go to a Oreilly autoparts store, they let you use a scanner for free.
Plug in under the dash by the steering wheel and it gives you a code. Go into the store tell them the code and they tell you what part it is and where. Buy part , go home and put it in.

Saved me lots of money over the years.

 

[Becker]

Yeah. My guess a speed sensor.

 

[The Great Oz]

If you've had work done on the brakes or you've done some damage to a wheel it might be a wheel sensor.
Otherwise it's likely a problem with the hydroboost. It can show a symptom like loss of braking assist, the pedal goes to the floor, loss of steering assist, or pulsations like a tire is skidding. Then it will be fine for three weeks. Then you'll blow through a stop sign. Get it replaced before you rear end someone.

 

[Shane T]

I just go to a Oreilly autoparts store, they let you use a scanner for free.
Plug in under the dash by the steering wheel and it gives you a code. Go into the store tell them the code and they tell you what part it is and where. Buy part , go home and put it in.

Saved me lots of money over the years.

Local discount parts stores aren't able to scan the system for ABS trouble codes, only engine related issues.

 

[rwcarpet]

I'm trying to find my repair manual for that van. My guess would be coroded wheel speed sensors, since you live in a snowy state that probably uses salt on the roads. If you can get to them, remove them and clean them up.

 

[Shane T]

I'm trying to find my repair manual for that van. My guess would be coroded wheel speed sensors, since you live in a snowy state that probably uses salt on the roads. If you can get to them, remove them and clean them up.

I have the factory shop manual, its not much help without the scan tool. These sensors are enclosed and don't get rusty as such, so likely on is just bad.

 

[Contemporary Carpet Clean]

As I stated even though the ABS sensor is "Enclosed"'/"Sealed" the seals go bad after a while and crap gets/seeps in after a while.

 

[rwcarpet]

I'm trying to find my repair manual for that van. My guess would be coroded wheel speed sensors, since you live in a snowy state that probably uses salt on the roads. If you can get to them, remove them and clean them up.

I have the factory shop manual, its not much help without the scan tool. These sensors are enclosed and don't get rusty as such, so likely on is just bad.

Still haven't found my shop manual...it's proably at the shop! You're right about the enclosed sensors. Try disabling (pull the fuse) on the ABS. It will still stop the van, but with out the anti-lock feature.

 

[Magic One]

Sad news, GM wants $1000 to repair ABS. My mechanic wants $895. You need a scan tool to find the problem.

 

[Shane T]

Sad news, GM wants $1000 to repair ABS. My mechanic wants $895. You need a scan tool to find the problem.

The sensors cost about $55 each and it's not a bad job, so I should have just replaced them myself. I took it in to a local shop yesterday, they had it done in a few hours. Cost $400

 

[Magic One]

Wow , my estimates where too high.