ABS Question

[ar0ck]

My ABS is acting funny lately, After about 5 minutes or so of driving my ABS INOP light & ASR OFF light will come on, and neither work. Today I was comming to a stop after some romping on the highway, and the car shuttered and the RPM's droped as if my ASR was comming on (retard the timing) and then the breaks pulled away for the ABS, then both lights came on. The car did not stall.

Whats the deal, I know its almost time for a brake job, but can this effect the sensors? I knew I had a problem similar to this before but it was only in the rain, so the sensors must have gone wacky.

Is their a way to Diagnose this?

[89 Trans Am WS6]

Scan the ABS system..

You said it happens as you pick up speed?

If so it could be a wheel speed sensor..

Similar to how the light comes on when you put your car on a dyno..it senses the rear wheels moving and the front not, so it throws the light..

If you have a inop WSS that could be the cause.

also in theory, worn break pads could, in a extreme case cause the abs to stop working.

As the breaks wear the piston in the calipers come further and further out, this lowering the level of fluid in the master. If the level is low enough the car will disbable ABS breaking.

Is the red break light on aswell?(the one that comes on when you set the ebrake)

Or just the amber aBS?

[ar0ck]

Just the Amber ABS Inop light, Im going to check the level of brake fluid in the car right now.

[ar0ck]

Checked my power brake fluid and it was low, so I added some more fluid to the proper fill line. Also my dad checked the connections at the ABS/TCS box in the front, just to see if anything was loose in an obvious place. I drove the car around the block, and everything was good. When I took it on the highway when I got off, the lights came on, so at the next stop sign, I killed the car and started it back up, the lights went away.

Any Ideas?

This is a new thing since our last major rain fall, only thing that has changed is alittle more highway use of the car then local driving.

[9secfirebird]

brake fluid will not set off an abs inop light. and since ya topped it off, when ya go to compress the calipers to do the brake job its all gonna squirt out onto the frame, it will all get cleaned up. you need to scan the abs computer for codes. if ya need help, i can helpy a out one day if ya wanna stop after work. i do work for alot of peopleon this board. i live in clinton.

[tastyle88]

dont know if this will help but my pickup 99-s-10 did same thing turned out to be a xtreamly dirty senser may want to clean then this can happen when brakes are worn down and dust may be on sensor

[89 Trans Am WS6]

brake fluid will not set off an abs inop light. and since ya topped it off, when ya go to compress the calipers to do the brake job its all gonna squirt out onto the frame, it will all get cleaned up. you need to scan the abs computer for codes. if ya need help, i can helpy a out one day if ya wanna stop after work. i do work for alot of peopleon this board. i live in clinton.

Care to make a wager?

Low fluid level in a master WILL disable ABS operation.

and it IS a common problem in the field. It doesnt even have to be caused by a leak, just by pad wear bringing the fluid levels down.

A perfect example car of this was the 97 and previous ford windstars which had a extremly sensative master cylinder which read low fluid levels way to soon, thus deactivating the abs.

If it happened after some serious rain and stuff, i would look at the wheel speed sensors, the exciter wheels and all that good stuff. Clean em carefully and see if your problem goes away. Sometimes debris can block the wheel speed signal from registering properly.

Still though, the easiest way is to scan the car.

edit"
Also, if you pump the breaks after you finish one side, then move to the other it will greatly reduce the amount of fluid that drips out. (onto the floor). If its that full, you can always take moms turkey baster and suck some out of the master first..just uhh..dont put it back in the drawer ;(

[Savage_Messiah]

Try this: unhook your battery, and make sure theres no corrosion.

For a while my brake (ebrake) and abs inop lights would come on out of nowhere, and sometimes the car wouldnt start, we had no idea what it was. Turned otu it was corrosion on the battery terminals, so we cleaned it all with baking soda/water, then but some dielectric grease, and it was all fine.

[The Fixer]

Also, if you pump the breaks after you finish one side, then move to the other it will greatly reduce the amount of fluid that drips out. (onto the floor). If its that full, you can always take moms turkey baster and suck some out of the master first..just uhh..dont put it back in the drawer ;(

Good tip. Another idea is to just roll up some paper towels and put them in the fill hole of the master. I had to do this on my sister-in-law's Hyundai when I did the brakes. I added fluid a week before because the pads were really low and the light was coming on in the dash. Once I compressed the calipers to put the new pads on, the fluid level came up and I just soaked it up with the towels.