anti lock brakes engaging erratically

[cbass]

Hey Guys,
I tried to search for this, but the search engine won't allow a search on "abs" so all the search results that came up were bogus. Nobody writes out "Anti-lock Brakes" anywhere except me in the title.

Anyway, I am posting this for my dad and I have not yet looked at the truck, but I would like some information so I can know better what I should look for. Here's the scenario as explained by my dad:

'94 Disco 1 had a tire blowout a few weeks ago (don't know if that's related or not) and ever since about that time, the ABS has been engaging prematurely when there is NO wheel skid. It doesn't do it all the time, but many times under normal braking circumstances, the ABS will kick in.

Any ideas as to what I could check? I was thinking somewhere along the lines of a wheelspeed sensor or something like that.

TIA!

 

[Joey]

I would reseat the front sensors and flush the brake system.

If you don't care about ABS and don't take my advise as legal or the LR standard... but if you remove the fuse in the fuse block under the hood, ABS issues will go away.....

My advise is not in any way a suggestion or the proper way to fix anything, but in rare cases it works

 

[Chris-St Louis]

This is a set up.

 

[cbass]

Did I miss something Chris? If I'm out of the loop, fill me in

 

[Chris-St Louis]

Search for the 3rd most read post on here. You'll see.

That Being said......

The ABS computer has to see 2 things before it engages the system.

1) The brake is applied (A 12 volt signal from the brake switch)
2) One of the 4 Wheel Speed Sensors to indicate Zero.

If the abs turned on at the end of the stop, it is likely your sesnor has rust,crud or whatever on it, or isn't seated all the way.

This is assuming your swivel is in spec.

The signal gets weaker as the wheel speed decreases.

I would pull out all the sensors and clean them off (Steel Wool is fine) and reinsert them untill they bottom out...They self adjust.

A complete sensor failure means the computer would see Zero wheel speed even without the brake pedal pushed.
The computer is smart enough to know this isn't right, and will set a code.

If your ABS light isn't on, the most likely cause is a dirty/misadjusted sensor