Brakes have a mind of their own, ABS problem

[FredK]

Yeah, I already went through most of the braking system eliminating the variables, so it was a relief to find it was something simple.

The L/R sensors look nearly identical. Hopefully they ARE different, and it's not me just swapping sensors out and imagining that I solved the problem. I'll be testing it out and I'll report back in a few weeks.

[PhillyG]

Good job. Great to hear it was something so simple.

[1990m3]

wow, congrats on fixing it...that has been lingering for a long time. I have had problems like that on my car that linger forever and it turns out to be something simple and easy -- in your case no cost either!

I've swapped sensors out and back on my car when the suspension was going through a redo and I must have been lucky. I had no idea that sensors were L/R specific. Now I'll think I'll check mine just to be sure it's right...

[atomic]

:woowoo:

[FredK]

FIXED!

I went outside an hour ago and took a look at the front brake sensors. I looked at the last three digits on the L and R sensors. They were the same, 982. I knew that the E30 ABS system uses two different sensors up front, so I looked at the ETK. It turns out that the left side sensor is 981 and the right side is 982. So, I had two right hand side sensors installed.

I looked in my pile o' sensors, and found a left side sensor. I installed it and I just got back from a test drive. Works 100%. No more premature wheel lockup, and very even braking all around.

This error must have happened when I just arbitrarily looked in my pile o' sensors and installed two front sensors back when I built my car up last August, without paying attention to the L/R difference in the sensors. The right side sensor has a longer lead length, and the left side sensor has a shorter lead length, and they must pass different signals to the ABS computer. I've been fighting this problem for a long time, and I'm just glad I finally found the source of the problem.

[FredK]

Haha, I changed the pads on a friend's 86es yesterday, and the car brakes better than mine! The ABS still works great.

[PhillyG]

I just dunno if I could trust a 22 yearold ABS system.

and wizard would you consider a car without abs a malfunctioning car?

[FredK]

Yep, I replaced the ABS pump with a known good one. I also swapped computers with a known good one from another 318is.

I took the car for a test drive after having rebuilt the calipers. The car now pulls up square, but the ABS is still pulsing when it shouldn't be.

I will delve into the electrical in a couple weeks and keep this thread updated. I have a full set of ABS sensors that I will swap in and see if that does anything. I already pulled the rear sensors and cleaned them and checked the tone wheels, and everything looked fine. No nicks, no dirt, nothing.

[rThor432]

I've seen this problem before. The car had a bad ABS unit. The unit itself was crudded up inside. The fluid had probably never been flushed and there was a bit of rust inside the unit as well. I replaced the unit with another one that I pulled from the boneyard and the problem didnt come back.

Just an idea, dont know if you checked that or not yet.

Good luck!

[MrWizard]

Sure but when driving around town are you speeding? no. Unless your an idiot. I drive pretty damn slow tbh. I rather have no ABS than a malfunctioning abs system.

Many fatal collisions happen at speeds of less than 40mph.



I'd rather walk than drive a malfuntioning car.

Please don't take this as an insult.

[PhillyG]

Sure but when driving around town are you speeding? no. Unless your an idiot. I drive pretty damn slow tbh. I rather have no ABS than a malfunctioning abs system.

[MrWizard]

ABS it there to keep your car straight and at optimal slowing in a panic stop situation and was was mandated by the feds to be installed on all cars by the late 80s.

A highly skilled driver doesn't need this however it does do what it's supposed to better than any human being could.

To have the ABS circumvented intentionally on a car driven on the street could mean the difference between being involved in a terribly unfortunate accident and being charged with negligent homicide / manslaughter.

This legal president has already been set and tested.

Don't be stupid.

[PhillyG]

Your A/C isn't a safety system. You do like Fred said and disable it temporarily, not remove the entire system.

My A/C is removed because I don't like it and it's heavy as shit. It also didn't work. But it's not going to save my life. Again, get a clue.

Not all of the e30's came with abs. My 84 had no abs system.

And if removing the ABS system is that big of a safety hazard to you maybe you should try some driving courses.

Not trying to be a dick. But I just don't see why you have such an attitude.

[Jand3rson]

On that note everyone who removes their A/c system because it doesn't work is a fucking tard too right?

Your A/C isn't a safety system. You do like Fred said and disable it temporarily, not remove the entire system.

My A/C is removed because I don't like it and it's heavy as shit. It also didn't work. But it's not going to save my life. Again, get a clue.

[FredK]

It IS a safety issue, and if I daily drove the car I'd at least disable the ABS. Fortunately it's an occasional-use car, so there's no harm in not removing it until I figure out what the problem is.