ABS problem 89 xj

[torfinn]

I have noticed lately that abs kicks in when breaking on dry roads. Today the check antilock light came on. I took it for a test drive later. It kicks in when breaking and turning left at the same time. I can feel the pulsation in the pedal and it is loosing breaking power. The light does not come on. This does not happen when turning to the right and breaking. I think it might be a wheel sensor that needs adjustment, or may be a faulty wire. Are all sensors adjustable?

Torfinn

 

[red91]

I don't believe that they are. If I understnad it only senses the ridges in the ABS tone ring. If it fails...replace it...OR just pull the ABS fuse and you have NORMAL braking ability.

 

[Headache]

I have had the same on my 91 XJ.
Possible causes:
- corroded/dirty ABS rings
- faulty/displaced sensor

Not all sensors are adjustable, but even the non-adjustable ones should be placed with extreme accuracy.

If you want to disable the system, I suggest that you disconnect a wheel sensor (you can do it right at the ABS computer underneath the backseat). Thus, the ABS will automatically go into a safe normal braking mode. That is what I have done. This will make the amber warning light light up permanently, but it will keep all other warning functions (i.e. the red warning light) operational.

 

[bn6339]

Just a suggestion, but perhaps you ought to consider replacing that poorly designed POS with regular standard brakes....a fairly easy conversion with the correct parts, and MUCH safer than what you have now....a search on will give you most of the info you need.....I converted mine, and don't miss the ABS at all.

Bret S Gray
1990 XJ Laredo
3.5 RE Lift and other miscellany....
in the shop for more mods!!!

 

[Headache]

For conversion: see http://www.naxja.org/html/techarticles/uninstall_OEM_ABS.htm

 

[torfinn]

Found the fault

I disconnected the two front sensors under the hood, and connected an ohm meter they were both 6,6 kohm when both wheels were straight. When turned to the left the left sensor increased in value a lot, 10 times. Pulled out the wire from the protective loom and it was missing insulation at least three places. Soldered in a piece of new wire and that was it.

Torfinn

 

[Greg Smith]

Re: Found the fault

Torfinn,
Great that you fixed it. By the way all the wheel sensors on the 89 are adjustable. The air gap (distance from tone wheel teeth) on the front ones is set using an brass or plastic feeler gauge and should be set per the factory manual to .013-.019 inch (.33-.48 mm). I usually set mine near the lower end of the number range. Rear sensor is set to .030 - .036 inch (.76 - .91 mm). Greg

I disconnected the two front sensors under the hood, and connected an ohm meter they were both 6,6 kohm when both wheels were straight. When turned to the left the left sensor increased in value a lot, 10 times. Pulled out the wire from the protective loom and it was missing insulation at least three places. Soldered in a piece of new wire and that was it.

Torfinn

 

[torfinn]

I have done both sides with new wires. Both wires were equally bad. Soldered in a new length of wire. Used a crimp wire loom over the joint. Now the breakes are like new.


I recommend doing this on models that have abs brakes and being more than 10 years old. The wire insulation gets brittle as it gets old.

Torfinn

 

[gatorback]

did 89 have abs i thought it didnt come until 90 as a option

 

[jeepdude10000]

Ya there were ABS in 89 in which i have , and they are crap, since I put bigger tires on, never have to worry about tire lockup though.