E34 Touring leaking self levelling suspension

[matt21]

Hi folks

after some pretty urgent advise regarding my 1994 525i Touring.

the rear suspension for the past year or so and 20k has always rattled and banged a bit but never really bothered me. A leaking rear shock was an advisory on the MoT.

Obviously these have SLS (self levelling suspension) and this weekend it sprung a leak near the passenger side rear wheel.

Question is what should I do.

Should I make a bypass loop as someone suggested on the BMW forum, or should I replace the whole lot for normal suspension.

I have very little knowledge but dont want this to be the death of my car.

Should I just keep driving it til it goes kaputt (as it runs from same resevoir as PAS fluid) or should I just get it over and done with?

Please help!

[mmm-five]

You don't want the fluid to get so low that you start damaging the PAS box as well as that's a lot harder to replace than the suspension.

Whether you go for new suspension or not, you will have to cap/bypass the leak anyway.

I put standard rears on my e34 M5 and removed the accumulators - but I put a loop in the SLS lines just in front of the N/S rear wheel where the pipes go into the bracket before the SLS valve.

I did think of replacing the entire SLS piping system, but it was going to cost something like £1000 in parts & labour so ended up just looping the system to give the pump a return - can't cap it at the rear otherwise you'll have no return to the reservoir.

Luckily you've already got standard top-mounts and so the choices for suspension are much wider than for us M5 boys - although I did end up replacing the whole system anyway to fit sports suspension all round.

I got mine done by Darjac Racing (Darren Farrell - 07807 689538) near Chelmsford as he does all my M5 stuff - even though he's over 230 miles from me in Liverpool.

[sniff diesel]

I'm sure you can get a set of normal suspension pretty cheaply Matt.

I've just sold some of the original springs and dampers that old red E36 for £70 as I'm finally getting round to fitting the coilovers. Fish about on Ebay or in the classifieds on here.

[matt21]

yeah sure i can get some cheap system.

really dont wan to bin it, most would in this throw away society but determined to soldier it on barely run in at 219400

decided to bypass the system from the front then buy some rear suspension components.

Two questions?

Does standard suspension fit straight onto E34s? Also if the top mounts are standard are the bottom?

or have I just contradicted myself!!

[sniff diesel]

Afraid I don't know a thing about E34's, if it were an E36 I could help.

[bpizarro]

Hello, has anyone been successful in replacing an E34 SLS system with a conventional spring & shock system? Any clues regarding where to buy new standard-height springs & shocks, how to by-pass the electronic sensors, and whether the top mount must also be replaced? - Thanks.

[matt21]

bpizarro said:

Hello, has anyone been successful in replacing an E34 SLS system with a conventional spring & shock system? Any clues regarding where to buy new standard-height springs & shocks, how to by-pass the electronic sensors, and whether the top mount must also be replaced? - Thanks.

I replaced mine, worked fine. Got standard shocks and springs from GSF, unplugged electronic sensors, cleaned the fluid to drain out of the SLS pipes and didnt change the top mounts.

Wasnt a 5min job and not cheap but far cheaper than the grand I got quoted to bypass the whole system!

[mmm-five]

bpizarro said:

Hello, has anyone been successful in replacing an E34 SLS system with a conventional spring & shock system? Any clues regarding where to buy new standard-height springs & shocks, how to by-pass the electronic sensors, and whether the top mount must also be replaced? - Thanks.

I did mine last year, and got it all done at Darjac in Essex

He got some colleagues in a well-known & respected suspension company to do me a custom set-up, plus some other bits he's sourced himself. Since mine was the prototype and I was over the moon with it, he started offering it to his other customers (done about 5 others so far - see m5board.com for more info). Don't know the current price, but it was about a third of the price of new EDC/SLS.

[bpizarro]

Hello Matt21:

Is GSF an aftermarket spring manufacturer? If so, could you please provide their address, E-mail or telephone numbers? Here in Peru, I can get Bilstein or Boge shock absorbers at reasonable prices, but I am having trouble finding standard rear springs for a 525i Touring. BMW dealer prices are extremely high.

Thank you all for your feedback.

[matt21]

bpizarro said:

Hello Matt21:

Is GSF an aftermarket spring manufacturer? If so, could you please provide their address, E-mail or telephone numbers? Here in Peru, I can get Bilstein or Boge shock absorbers at reasonable prices, but I am having trouble finding standard rear springs for a 525i Touring. BMW dealer prices are extremely high.

Thank you all for your feedback.

GSF is German Swedish and French. There should be plenty of local stores around, google it.

I am sure you have similar over there.

[bpizarro]

Thank you, Matt21. I found a new set of standard height springs and Bilstein shock absorbers, and will prepare a hydraulic by-pass pipe tomorrow. Would you have any tips regarding the BMW Check-Control sensor connections?

[matt21]

bpizarro said:

Thank you, Matt21. I found a new set of standard height springs and Bilstein shock absorbers, and will prepare a hydraulic by-pass pipe tomorrow. Would you have any tips regarding the BMW Check-Control sensor connections?

Just unplugged mine, was no problem!

[bpizarro]

Thanks again. I installed new standard springs (which are taller then the SLS springs), new Bilstein shock absorbers and upper mounts. The ride quality is back to normal now, but the vehicle height has unexpectedly dropped about 20mm in the rear, ... Am I doing something wrong? Also, regarding the hydraulic plumbing, I hooked up a by-pass pipe so oil could return to tank, but I have read in another BMW forum that some folks are simply plugging the pipes. Which is the best way to go?

[matt21]

bpizarro said:

Thanks again. I installed new standard springs (which are taller then the SLS springs), new Bilstein shock absorbers and upper mounts. The ride quality is back to normal now, but the vehicle height has unexpectedly dropped about 20mm in the rear, ... Am I doing something wrong? Also, regarding the hydraulic plumbing, I hooked up a by-pass pipe so oil could return to tank, but I have read in another BMW forum that some folks are simply plugging the pipes. Which is the best way to go?

Mine dropped too, was never an issue.

As the fluid circulates with the power steering fluid I dont believe you can just plug. I did what you did to make a smaller circuit for PAS fluid circulation. Just unplugged sensor.

[bpizarro]

Hello Matt21,
I unplugged the SLS sensor's electrical connection, but I still keep getting an error message in my Check Control console, after about 5 minutes of driving an unloaded vehicle. Today I reconnected the SLS sensor and disconnected the mechanical link, which I tied down at a "normal" position, but I keep getting the same error message. Any suggestions? Everything else is fine and the ride is excellent, but the message is very annoying.

[matt21]

bpizarro said:

Hello Matt21,
I unplugged the SLS sensor's electrical connection, but I still keep getting an error message in my Check Control console, after about 5 minutes of driving an unloaded vehicle. Today I reconnected the SLS sensor and disconnected the mechanical link, which I tied down at a "normal" position, but I keep getting the same error message. Any suggestions? Everything else is fine and the ride is excellent, but the message is very annoying.

what message are you getting?

[bpizarro]

The message in Spanish is "Regulacion de altura", meaning literally Height Adjustment. The sensor is on the right side, in front of the rear axle, and has a small link and a three-prong electrical connector. There is another link on the left side, which is connected to a hydraulic valve (hydraulic lines are now disconnected), but I do not see any electrical connections in this valve or in the accumulators.

[bpizarro]

Sorry, I need to correct my previous post. The message I am getting in Spanish is "REGULACION NIVEL", which alternates with "LIBRO INSTRUCCION". This translates to LEVEL ADJUSTMENT and INSTRUCTION BOOKLET or OWNERS MANUAL. The message comes on after several minutes (random, anywhere from 5 to 10 min), and resets after ignition shut off. - Thank you for your valuable advice.

[matt21]

bpizarro said:

Sorry, I need to correct my previous post. The message I am getting in Spanish is "REGULACION NIVEL", which alternates with "LIBRO INSTRUCCION". This translates to LEVEL ADJUSTMENT and INSTRUCTION BOOKLET or OWNERS MANUAL. The message comes on after several minutes (random, anywhere from 5 to 10 min), and resets after ignition shut off. - Thank you for your valuable advice.

sorry no idea, mine never said that?

does it ping up when the car is full.

mine occasionally said it was overweight if I had a full boot when it never said it prior to the SLS bypass.

[bpizarro]

Was the sensor you disconnected a small device, slightly larger than a match box, with a three-prong connector, located on the right side, in front of the rear axle? Maybe I unplugged the wrong device, ...