ABS Brake problem

[twexp]

Ok my 95 4x2 seems to be having an ABS brake problem. I had the light come on, then had the codes read. For $70 the mechanic said that the ABS solenoid was bad and no junkyards would sell it, but that he would get a new one (dealer) for $1400. So the first junkyard I called would sell it for $50 with a 90 days guarantee. Installed it and it worked great for a few weeks, now the light comes on once I hit 15 mph, which leads me to think it is a speed sensor issue or air in the line.

Here’s the dilemma, do I get the codes read again ($70), return the device (3 hours of labor wasted) or replace the speed sensors? Any advice is greatly appreciated!!!

 

[Rhett]

You should always fix things in order of cheapest and easiest to most expensive and hardest.

1) First, you should check the condition of your brake fluid. Old brake fluid often causes abs light; old fluid absorbs moisture and air which can set off the ABS light. Replace fluid if necessary. If that doesn't work,
2) second, remove the rear ABS sensor and clean it. If that doesn't work,
3) I would clean the front ABS sensors. They are not too easy to get to.
4) Replace all ABS sensors; one on each front wheel, one in the rear diff, one in the master cylinder; possibly more in your 2nd gen;
5) Replace ABS computer ($$ expensive)
6) Replace ABS proportioning valve ($$ expensive time and labor)

 

[twexp]

Thanks Rhett
I did replace all the brake fluid and bled the system with a vacume pump.
I did replace the solenoid/porportioning value since this is what code came up.
Since the problem still persits, my thought is that the code is bad (computer is hosed) or the mechanic made $70 and claimed that was the code. (would not give me a printout)
I will go with your suggestion and clean/replace the speed sensors.
If that doesn't help, get a rebuilt ABS computer. Napa is selling them for $200+.

How do I clean the sensors and do you have a suggestion for where to purchase the speed sensors?

 

[Rhett]

Keep in mind, cleaning sensors will not help if the sensors themselves are worn out.
You'll just have clean worn out sensors. hehe. Most commonly in these cases, I have found that one or more of the sensors are usually just worn out. If you replace, I would start with replacing the rear sensor first, as it's the cheapest and easiest to replace.

The rear sensor is threaded into the rear differential; near where the driveshaft comes in. Unplug it's electrical connector, and unscrew the sensor. Take some brake parts cleaner or something similar and clean the metal surface of the sensor. It may have some gray sludge on it; clean this off. Make sure it's dry before putting it back in.

The only way I know to clean the front sensors is to pull the front wheels, remove the hub assembly, if you have one, and then remove the brake caliper, and rotors. Then the front ABS sensors will be exposed. Clean them as above. As I said in the earlier post, it's difficult to get to the front ABS sensors, and removing all of that stuff is the only way I know of to get to them to clean them. Perhaps others have better suggestions; perhaps it can be done without removing the rotors.

 

[twexp]

Rhett
I have now replaced the back (differential) and the transmittion sensor (or what I hope is the ABS transmittion sensor) with no luck. I am still waiting on the front two (back order). I will update when they are in and that they will fix the problem.
The little yellow light is driving me nuts!!!!!! ABS ABS ABS.......etc that's all I see.....