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Discussion Starter · #1 ·
I have a 94 caprice classic LS. For months my ABS light has been coming on and recently it has become more frequent. It wouldn't come on during the initial test the car performs after start up, but while I would be driving.

I figured I'd start by cleaning the front sensors. Both of them are seized up.

I already started to break the right one out, but I was wondering if I could just remove the left rotor and clean the tip of the left sensor? And is there a better way of removal besides drilling? That seems to be one of the only options on most forums. For sensor installation, I heard you have to put a sealant on the sensor. Would Teflon tape be as effective? If anyone has a spare right sensor I’d be happy to buy it off them.

Thanks
 

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while its likely the front sensors are the usual culprits for an intermittant abs light, until you have it scanned and see what the specific code is you may be spending money unnecessarily.

first off, most intermittant sensor problems are from open circuits caused by broken wiring inside the harness.
so cleaning isnt going to help much unless you got alot of rust on the sensor and abs tone wheel and thats the problem instead of wiring.
and if you break one trying to take it out and its not the cause of the light they arent cheap new.

Ive found pb blaster soaking and rotating the sensor first before removing helps.
 

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Definitely pull codes before merely replacing parts, though I believe aftermarket has taken over and lowered the previously skyrocketing oem-only pricing.

I bed new sensors in silicone sealant, but that likely only helps removal a short while after installation. Plus, I had a defective brand-new sensor that drove me nuts diagnosing.
 

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The tip of the wheel sensor is magnetic and picks up all kinds of metal shavings. To clean, all you really can do is wipe the tip with a cloth and try to pull of the metal.

The sensor is a sealed unit and should not need any additional sealant but a little anti sieze or grease around the body may help if you try to remove it later. I have removed the bolt and then tried to wiggle the sensor out by lightly grasping the back side of the sensor with channel locks. This has usually just resulted in a cracking of the plastic housing. Another option is a deep 3/8" or 7/16" socket to fit over the top of the sensor and tap it out with a hammer.

All of this options are tough on the little plastic sensor if it is really stuck in there. I've tried PB blaster and all to get these out and never much success without chewing up the part. At this point my ABS is inoperative after the rear swap, so I will most likely be pulling the entire setup and cleaning up the engine bay a little more in the future. Never a big fan of ABS and there are a few discussions on the forum over the need/want of the system.
 

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The tip of the wheel sensor is magnetic and picks up all kinds of metal shavings. To clean, all you really can do is wipe the tip with a cloth and try to pull of the metal.

The sensor is a sealed unit and should not need any additional sealant but a little anti sieze or grease around the body may help if you try to remove it later. I have removed the bolt and then tried to wiggle the sensor out by lightly grasping the back side of the sensor with channel locks. This has usually just resulted in a cracking of the plastic housing. Another option is a deep 3/8" or 7/16" socket to fit over the top of the sensor and tap it out with a hammer.

All of this options are tough on the little plastic sensor if it is really stuck in there. I've tried PB blaster and all to get these out and never much success without chewing up the part. At this point my ABS is inoperative after the rear swap, so I will most likely be pulling the entire setup and cleaning up the engine bay a little more in the future. Never a big fan of ABS and there are a few discussions on the forum over the need/want of the system.
The easiest way to remove metal shaving from a magnet is with tape. The tape adhesion is stronger than the magnetic pull of the magnet. I have used this method on magnets for years, and it works every time. It will even work on neodymium magnets, which are as strong as they get.
 

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Discussion Starter · #6 ·
Thanks for the quick feedback everyone.

while its likely the front sensors are the usual culprits for an intermittant abs light, until you have it scanned and see what the specific code is you may be spending money unnecessarily.

first off, most intermittant sensor problems are from open circuits caused by broken wiring inside the harness.
so cleaning isnt going to help much unless you got alot of rust on the sensor and abs tone wheel and thats the problem instead of wiring.
and if you break one trying to take it out and its not the cause of the light they arent cheap new.

Ive found pb blaster soaking and rotating the sensor first before removing helps.
Good idea, it wouldn't be the first time I had problems with corroded connections in this car.


Definitely pull codes before merely replacing parts, though I believe aftermarket has taken over and lowered the previously skyrocketing oem-only pricing.

I bed new sensors in silicone sealant, but that likely only helps removal a short while after installation. Plus, I had a defective brand-new sensor that drove me nuts diagnosing.
The only reason I bring up the sealant is because my service manual mentions to use a wax type sealant specifically GM part number 12345489 (which has been discontinued) when installing a new sensor. It also says not to use grease. I'm guessing it's not a big deal since it will only help removal a short while after installation.

But I just wanna confirm that I can get to the tip of the sensor by taking off the rotor. I don't want to brake my left sensor when looking at it.

I ordered a new sensor today. I won't be able to install until this weekend. I'll pay attention to the condition of the wiring. I know the connector on the upper control arm near the right sensor was clean.
 

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Generally, you will not be able to get the sensor(s) out without damaging them. Such was the design (and it's shortcomings) at the time ABS was incorporated into the B-body.

There are a number of threads/posts that have talked about this over the life of the Forum--here's an example.

As others also suggested, it MAY not be a "sensor" problem that is causing your car's ABS malfunction...still, there's nothing wrong with cleaning the sensor tips.
 

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while its likely the front sensors are the usual culprits for an intermittant abs light, until you have it scanned and see what the specific code is you may be spending money unnecessarily.

first off, most intermittant sensor problems are from open circuits caused by broken wiring inside the harness.
so cleaning isnt going to help much unless you got alot of rust on the sensor and abs tone wheel and thats the problem instead of wiring.
and if you break one trying to take it out and its not the cause of the light they arent cheap new.

Ive found pb blaster soaking and rotating the sensor first before removing helps.
I agree with Mr Pogo. A bad or dirty sensor would rather set lights on all the time not intermittently. I have similar problem. The sensors just like the rest of the car are rust-free and very clean. I suspect something is going on inside the wiring or inside of the connector. Every time I play with the wire and connector the code and the lights disappear for a while. Something similar is going on with my EGR ? If it were a bad valve or solenoid why would it set occasional 32 code now and then?
 

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My rear ABS wire is broke at the connect to the rear sensor, any one as a spare harness or part of the harness from the back connection the the front? , have a 1995 caprice,
Thank you .
 

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The yellow connectors are notorious for crumbling with just a touch. I am not sure that the connectors are still available, but you can use any 2 wire waterproof connector to replace it. The wires are not polar sensitive.
 
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