SLS Troubleshooting Tips?

[ahager57]

I need some troubleshooting tips for the SLS on my 1989 e24. In a nutshell, its not working .. the pump isn't cycling, the ride is harsh although there is a little bit of rear suspension travel. Can anyone offer some troubleshooting tips? Before i invest in conventional replacement, i'd like to at least try to get it working. For example ... is there a way to manually trigger the pump to see if it even works?

[dwcains]

You might shoot a PM to member "JCS" in case he doesn't see this thread. he's the go-to for SLS.

[JCS]

57 Welcome,

You can remove the relay, and use elect connectors. photo #1.
And place on the red HOT wire, and the beige (light brown) GROUND wire,
attach to 12 volts, photo #2, and the pump should run.

If your pump leaks, I have a repair kit and or a rebuild service.
link : https://goo.gl/photos/eZCBHcaeY7dZ8jte7

IMG_1291.JPG

IMG_1293.JPG

[ahager57]

JCS - Awesome - Thanks so much! I am on the fence about changing everything out or attempting some repair ... so your guidance is much appreciated and will definitely help me figure things out! Bought this car from the original owner and its in pretty good shape for its age and mileage. It had been sitting for 2 years and was serviced to be sold ... so I have no idea how good/bad the SLS is and this will help me sort it out!

[ahager57]

Ok first "dumb" question ... is the relay in the trunk well attached to the pump?
Second dumb question ... could you please confirm whether or not there is any sort of connection between the SLS hydraulics and the brakes on the 1989 635?

[JCS]

Ok first "dumb" question ... is the relay in the trunk well attached to the pump?
Yes
Second dumb question ... could you please confirm whether or not there is any sort of connection between the SLS hydraulics and the brakes on the 1989 635?
No

[ahager57]

JCS - again, thanks a ton. Before I try too "cycle" the pump I am going to drain the reservoir - the fluid is "black" and does not look healthy ... and I think I'd rather waste a little on new fluid than run the risk of cycling some really bad fluid thru the pump. But - thanks again. Please tell me if I get to bothersome. Wanted an e24 for 25 years ... they are the Ronan of automobile design! So freakin cool.

[ahager57]

Jay - I finally got around to implementing the tests you suggested. But ... as de-coupled the electrical connections I noticed that they were pretty oily and dirty perhaps from some past fluid leak. I cleaned everything up, started the engin and immediately heard the pump cycling. It didn't run long - maybe 5 seconds - and the rear end came right up - and stayed up. I checked for leaks - non found yet but I'll watch it over the next few weeks. What a significant improvement in the ride - so thank-you again for the advice. THANKS!!!

[JCS]

57,

Awesome,
Maybe the relay is bad.

Best,