96 4runner ABS problem

[x000000x]

ABS unit started acting up this past week. sometimes it does it right when i start it up while im driving 1 - 5 mph. For instance when im turning to park into a parking spot the ABS pumps and makes a loud noise. It doesn't do it when im driving over 5 mph. Sometimes when coming to a stop sign during a slow roll it pumps too and i have to push the brake down fully for it to stop. It does it sometimes when im driving slow in a parking lot as well. Does anyone have any ideas what it could be?

Thanks,

 

[brian2sun]

Early 3rd gen ABS sucks. I disabled mine by pulling the fuse under the hood (which the fuse block must be unbolted and the ABS fuse is held by a screw underneath). Many will say not to disable ABS, but it was the right thing for me because mine would kick on way too much and wouldn't stop my truck in a reasonable amount of time.

 

[trulli3300]

My 99 Limited is also doing this.

My 99 Limited is also doing this. It's been doing it for about 8 mos. Now that winter is coming, i'm more likely to depend on my ABS. Sometimes due to vibration or bump, i hear my ABS pumping. I thought it was due to worn old pads and shoes so I did a complete changeover including new discs in front. After a while, once it keeps tripping itself, the ABS light will come on and remain on. A few cycles of turning off and on the ignition cures the light. Any ideas what it could be would be of great help. Dealer or shop is usually the last resort.

 

[x000000x]

My 99 Limited is also doing this. It's been doing it for about 8 mos. Now that winter is coming, i'm more likely to depend on my ABS. Sometimes due to vibration or bump, i hear my ABS pumping. I thought it was due to worn old pads and shoes so I did a complete changeover including new discs in front. After a while, once it keeps tripping itself, the ABS light will come on and remain on. A few cycles of turning off and on the ignition cures the light. Any ideas what it could be would be of great help. Dealer or shop is usually the last resort.

I did a change over as well because i was due but it didn't make it better. My ABS light does come on time to time but will turn off after i restart the truck. It's just odd that it does it under 5mph and pumps away when im turning into a parking spot.

 

[theizzardking]

My 99 Limited is also doing this. It's been doing it for about 8 mos. Now that winter is coming, i'm more likely to depend on my ABS. Sometimes due to vibration or bump, i hear my ABS pumping. I thought it was due to worn old pads and shoes so I did a complete changeover including new discs in front. After a while, once it keeps tripping itself, the ABS light will come on and remain on. A few cycles of turning off and on the ignition cures the light. Any ideas what it could be would be of great help. Dealer or shop is usually the last resort.

i'm no pro on this but it sounds like a bad or dirty abs sensor to me, from my understanding it's a magnetic system and can pick up bits of iron from the road and start to malfunction, if i had to say i would say it's either this or a lose connection or a pump/reservoir going bad.most likely the wheel speed sensor....
don;t go out and buy the $300 part though untill you get a few more to chime in on this as i'm not 100% sure and don't want you wasting your money.


what do you guys think about this? is it a bad signal coming from teh sensor setting the pump off every so often or is a leak from some where and the res. is having a hard time staying primed?

 

[trulli3300]

That's a good "heads up"

Thanks izzardking. There's a lot to know there. Does anybody know, how do you clean the sensors? Is it possible? My truck has more than 200k miles. I have experienced the ABS pumping at varying speeds under 30mph but most noticeable at lower speeds. Winter in Michigan = We need our ABS.

 

[trulli3300]

Hey x0

Hey x0, i put about 30 miles on my 4runner today in stop and go. I had ABS pumping in the parking lot but not enough to set off the ABS light. Are you having any luck? No one seems to have much more of an answer.

 

[theizzardking]

Hey x0, i put about 30 miles on my 4runner today in stop and go. I had ABS pumping in the parking lot but not enough to set off the ABS light. Are you having any luck? No one seems to have much more of an answer.

The sensors are located on the knuckle google abs sensor cleaning and your ride and have a search, i think the only way this will get fixed is a bit of tinkering or alot of money, hopefully the former.

Does your abs work? Have you tried to engage it?
Download the fam there's a link for it on google just search 4runner fsm have a look at the abs system and just start going through it.
I'm mobile right now so i can't do any of this for you i'll see what i can add tomorrow.
take care and drive safe!

 

[trulli3300]

The ABS works.

ABS works as long as it hasn't tripped itself into an "error" setting off the ABS light. As long as the light is off, it works. From my experience with Toyotas (9yrs sales) if the light is on, the system is in error so for protection, it does not function. By the way, funny you mention it, I am downloading the service manual right now. I just have to wait 15:00 minutes from rapidshare. I'll have a look at it this weekend. Thanks