LAD/self levelling elimination + LAD shock repair info

[shogun]

make some nice pics of that for further reference here. Also the dimensions of the fittings, so that it is in future easier to DIY.

[billbarr]

Struck out on getting fittings to make a steel line.They mainly do
truck stuff so no metric.I called bav auto and ordered the piece that they have in the kit since they have the sport bilsteins that I need. Not sure what it is that I am getting, but if it works, I will post pics and maybe it will help someone
to know that the piece is available separately.

Just checked the kit,Appears that what I bought is 2 plugs to plug the accumulators, after asking him if it was a u shaped line.
Oh well,plugs always come in handy.
I guess I will try and find a brake line

[billbarr]

I found a steel brake line in my stuff that fits perfectly on the existing
bracket.
it was for an e21 upgrade and had 2 female ends

[WhiteSe7en]

Shogun: How can you tell without loading your car with people, if your SLS is working properly?

The reason I ask this, is because I've noticed that when the car is parked and not running, the rear end sits a little low. Once it is cranked however, the rear end lifts up so that it is inline with the front end. There is no indicator however on the obc that the rear end has done anything. When I first got the car, when I had more than two people in the car, I would get a message on the dash that said "suspension leveling", now I get nothing. Just curious

[shogun]

check riding height.
Bentley's has a table for LAD equipped cars as follows:
Wheels Rear ride height
15 in. 522 +/-3 mm (20.55 +/- 0.4 inches)
16 in. 529 +/-3 mm (20.93 +/- 0.1 inches)
17 in. 545 +/-3 mm (21.46 +/- 0.1 inches)

Ride height is measured from the lower edge of the wheel arch to the bottom edge of the wheel rim (not the ground).

In case it drops over night in the rear, then I would first check if the regulating valve is really at zero = the return valve line is closed.
On the side of the regulationg valve is the lever. In this lever is a hole, in the regulating valve body is a hole, when both are in line and you can put a screwdriver thru both, then you have zero, then no fluid should go in or go out of the rear system from regulating valve.

Bryan has pics of this, and adjusting is here, both links here
under fixes LAD
http://twrite.org/shogunnew/topmenu.html

so when you have set the correct riding height, adjust the bar which controls the lever of the regulating valve in such a way, that the regulating valve is at zero position.

Suspension leveling warning you only get when the wheel angle exceeds are certain degree, see Bentley manual. Or the lever at rear axle is not correctly set.

[WhiteSe7en]

Thank you so much shogun for all the great information.

[shogun]

Sus warning elimination: Removing the "SUSPN LEVELING" warning message
https://www.youtube.com/watch?v=nwUblJyhPLs

[shogun]

I have read that the self levelling pump can be easiest modified from dual pump to single pump by just removing the spring and valve for the self levelling section. There are on the power steering pump 2 large bolts/plugs and underneath are the parts in question. One of these bolts is shown here, my buddy made me a special tool for that http://alpinakozou.web.fc2.com/file/.../20110309.html
On one of these pics with the pump repair you can see the spring and piston http://alpinakozou.web.fc2.com/file/...20110506b.html

I am not yet 100% sure which piston has to be removed, if someone has a pic and can point on it, please do so.

Here on my website scroll down till you find in the technical description item 1.4.2 the tandel pump cross section, and on the top of that you see Niveauregulierung http://twrite.org/shogunnew/systems/lad.html
Some pics of the overhaul we made in 2008 http://www.bimmerboard.com/forums/posts/526913

Troubleshooting Guide Steering:
Heavy Steering Effort
1. low on power steering fluid
2. loose rack piston
3. restricted fluid passages in gear assembly
4. bent or damaged rack assembly
5. internal fluid leakage in valve assy
6. external fluid leakge at pump
7. incorrect drive belt tension
8. external fluid leakage at hoses
9. incorrect engine idle speed
10. weak pump flow pressure

Hissing noise when parking
1, internal leakage in steering gear
2. steering wheel at end of travel (normal)
3. when turning steering wheel at standstill (normal)

Growl in steering pump
1. excessive pressure in hoses
2. worn cam ring in pump
3. scored thrust plates or rotor in pump
4. scored pressure plates

Swish noise in pump
defective flow control valve

Whine in pump
1. air in power steering fluid
2. low power steering fluid level
3. pressure hose or line contacting other parts
4. mis-aligned hose and line brackets
5. missing or damaged pump cover O-ring

Rattle in steering
1. pressure hose contacting another part
2. loose pitman shaft
3. lost pitman arm
4. loose tie rod ends
5. loose rack and pinion mounts
6. loose steering gear housing bolts
7. loose steering gear adjustments

Car wanders to one side
1. incorrect front wheel allignment
2. unbalanced steering gear valve
3. loose tie rod ends

Steering wheel surges or jerks
1. low power steering fluid level
2. loose pump drive belt
3. weak pump pressure
4. stickingflow control valve

Excessive play in steering wheel
1. air in hydraulic system
2. incorrect steering gear adjustment
3. loose steering gear coupling
4. loose steering shaft universal joint
5. faulty rotary valve

Increased steering effort
1. slipping pump drive belt
2. internal pump leakage
3. low power steering fluid level
4. too low engine idle speed
5. air in hydraulic system
6. weak pump output
7. malfunctioning steering gear

Poor return of steering wheel
1. maladjusted steering wheel
2. dry ball joints or linkage joints
3. binding ball joints or linkage joints
4. incorrect front wheel alignment
5. maladjusted hweel bearings
6. kinked return hoses
7. internal pump leakage
8. contaminated power steering fluid
9. mis-aligned steering gear to steering column
10. tight steering shaft bearings or bushings
11. bent or damaged rack
12. sticking or plugged spool valve

This of course does not all fit for our system, but most of it. >30 pages of education from http://www.gates.com/ Gates Auto Education

[shogun]

Trying to collect some more info on LAD repairs, replacement etc, so if anyone knows links or has pics or info, please add here
http://www.bimmerboard.com/forums/posts/779720/
http://www.bimmerboard.com/forums/posts/779739
http://www.bimmerboard.com/forums/posts/831490
http://www.bimmerboard.com/forums/posts/657366/
http://www.bimmerboard.com/forums/posts/1245907/
here you can see all components of the rear axle when we removed it from a 750iL http://www.bimmerboard.com/forums/posts/272552/
http://www.bimmerboard.com/forums/posts/1226922/
http://www.bimmerboard.com/forums/posts/508927/
http://www.bimmerboard.com/forums/posts/509799
http://www.bimmerboard.com/forums/posts/511327
http://bmwe32.masscom.net/gavin/LAD_strut_rebuild.htm
http://bmwe32.masscom.net/sean750/LA...Ddustcover.htm
http://bmwe32.masscom.net/sean750/LA...cumulators.htm
http://www.bryanborough.com/750iL/
http://www.7-forum.com/forum/5/dicht...er-171788.html

[shogun]

On my photobucket site there I made an LAD section now with more pics http://s71.photobucket.com/user/shog...?sort=4&page=1
Whoever has more info, pics or dimensions of repair parts like seals, O-rings etc., please add here, thanks.

[shogun]

I found > 10 years ago on the German E34 M5 forum an official technical paper with drawings and technical details obout the LAD system, the post is from 2005. As one can only read in that tech section when registered, I re-type that here from Alles zum BMW M5 E34 Tipps & Tricks Niveaulift und dessen Bauteile

This states, that SLS/LAD shocks are o.k., when they have outside a bit of oil misting.


Niveaulift Schwitzöl
An den hinteren Federbeinen der Niveauregulierung ist generell ein leichter Oelaustritt ueber die Kolbenstangefuehrung vorhanden. Die Kolbenstange schleppt einen duennen Oelfilm mit, der sich ausserhalb der Dichtungs- und Fuehrungseinheit sammelt. Diese Oelleckage ist prinzipbedingt durch den hohen Systemdruck gegeben und ist im Gegensatz zu herkoemmlichen Federbeinen, die unter keinem oder geringem Systemdruck stehen, normal.

Ausserdem kann beim Anheben des Fahrzeuges mit haengenden Raedern durch Schraegstellung der Federbeine ein momentanes Ueberlaufen des angesammelten Oeles beobachtet werden. Auch dies ist normal. Das uebergelaufene Oel ist vor dem Ablassen des Fahrzeuges unbedingt abzuwischen, um keinen wirklichen Oelverlust vorzutaeuschen! Oelstand im Ausgleichsbehaelter pruefen, gegebenenfalls nachfuellen. Federbeine fuer Niveauregulierung mit nach oben ausfahrenden Kolbenstangen duerfen bis maximal ueber die halbe Daempferlaenge am Aussenrohr oelfeucht sein - sie duerfen "schwitzen".

translated:

LAD shocks oil misting
At the rear LAD struts a slight oil misting around the piston rod guide is generally existing. The piston rod drags with a thin oil film which accumulates outside the sealing and guide unit. This oil leak is given in principle by the high pressure system and is in contrast to conventional shock absorbers, which are under little or no system pressure, normal.

Furthermore, when lifting the vehicle with wheels hanging a momentary overflowing of the accumulated oil from the struts can be observed. Again, this is normal. The excess oil should be wiped off by the car mechanic in the shop before the car is talken off the lift, this to avoid complains, this is no real oil loss!
Check power steering fluid in the reservoir tank, if necessary, refill.
Suspensions struts for self leveling with the extending upward piston rods are allowed to a maximum of about half shock length to be oil misting at the outer tube - they are allowed to "sweat".
--------------------------------------

Re-typed and translated from an official paper posted in the German E34 M5 forum by Oldie 20/01/2004, level lift and its components.

And here another general info about oil misting:
Bulletin Number: Tech 01_09 November 16, 2009 Technical Bulletin –Shock Inspection
Misting vs. Leaking Commercial Vehicle Shock Absorber
Many technicians find it difficult to differentiate between a “misting” shock and a leaking shock that needs replacement.
Misting is a perfectly normal and necessary function of a commercial vehicle shock absorber. By design, the piston rod carries a film of oil through the rod seal to lubricate the seal lips, thereby reducing friction / wear at the seal contact area, and prolonging seal life. Misting occurs when the hot piston rod is drawn out of the shock body and the microscopic film of hot oil on the rod turns to vapor. This vapor, or mist, condenses when it reaches the cooler outside air, and forms a film on the outside of the shock body.
The film will attract road dust and debris, and will often coat the entire body of the shock
Rod seals may leak as a result of extreme wear, contamination, or defect. A leaking shock will show clear signs of oil leaking in streams from the upper seal down the shock body and may drip from the shock. Each twin-tube style shock has a reservoir that contains oil and air. The typical heavy vehicle shock can hold up to a liter of oil, and would have to lose more than 10% of its volume before damping performance would be affected.
NOTE: Some minor streaking of oil may appear on the shock body during initial stroking. This is the result of the seal “setting” and purging any oil (from assembly) from the seal. This is not to be mistaken as a failure, as it is temporary and totals only a few milliliters of oil.
Take the Heat Test
Shock absorbers function at temperatures ranging from ambient to 350 degrees Fahrenheit. A shock's role is to dampen the oscillation of the truck's springs. It does this by transforming the energy produced by the spring to heat and dissipating it. As a result the shock body should be slightly warm to hot after normal use.If ride deterioration is experienced and there is suspicion that a shock has failed internally, which is visually undetectable, perform the following "Shock Heat Test" within a few minutes of operating the equipment.
1. Drive the vehicle at moderate speeds for at least 15 minutes.
2. Within a few minutes of driving the vehicle, check the temperature of the main shock absorber body below the dust tube after first establishing a reference temperature of the surrounding chassis frame. WARNING: DO NOT touch the shock as it may be hot and could cause a burn injury - an infrared thermometer gun or similar measuring device is recommended.
3. All shock absorbers should be warmer than the chassis. Suspect a failure in any shock absorber that is noticeably cooler than its mate on the other end of the axle. Different temperatures from axle to axle do not indicate failures, but a cooler temperature on any one axle does warrant removal and examination of the cooler shock absorber. To inspect for an internal failure, remove and shake the suspected shock. Listen for the sound of metal components rattling inside which can indicate that the shock has an internal failure.
More there, including very good pics explaining light misting, medium misting, heavy misting, leaking http://gabriel.com/wp-content/upload...ECH-_01_09.pdf

[NMBMW]

LAD.jpg

I recently purchased a 94 740iL that had the LAD bypass done here, above the left front wheel well, but the hose used split and leaked. I am having trouble finding a way to connect a hose that won't split or pop off under pressure. I tried a hydraulic hose but it's so thick I can't get it clamped down with worm drive clamps. I was then thinking to splice brake lines to connect them but can't get the metal lines off because one line runs directly to the ABS/ASC+T Hydraulic unit and I have no way of getting under that to unhook the line. I also tried unplugging the ABS/ASC+T Hydraulic unit and that seemed to remove a lot of pressure but I'm still splitting the fuel line hoses I'm using. How are you guys attaching a hose that can stand up to the high pressure in this system? Have you seen a LAD bypass done in this location before? Thanks!

[Spvrdx]

Can you use different coil springs for the self elimination kit instead of the BMW factory designed coil springs

[shogun]

yes, if you want to install lowering kits or whatever.

[Spvrdx]

Yea what's the cheapest coil springs that's durable because the BMW factory ones are 150 for each spring I'm trying to save money

- - - Updated - - -

Basically I'm taking out the self leveling rear struts in a 91 750il an doing regular shocks

[shogun]

Do not know what is the cheapest, there are many, Eibach, Apex, B+G, H&R, ST, WEITEC, Spax etc, check the net http://www.europerformance.co.uk/pag...oweringsprings

[Spvrdx]

thank U I looked around but just didn't find much for the 1991 750il.... do U think I can use 735i rear shocks on the 750il both same year 91

[shogun]

Might be a bit difference in the spring due to different weight on the rear between a short wheel and long wheel base, here is some info http://www.bimmerforums.com/forum/sh...ility-with-E34
http://www.nmia.com/~dgnrg/page_27.htm
If you want to go cheapest, try for example LESJOFORS http://www.ebay.co.uk/itm/2-x-LESJOF...wAAOSwVllXHMn0
KYB is even cheaper a pair for GBP 41.45 + shipping, KYB Suspension Coil Spring K-Flex - Rear - PN RA5021, also fits E32 750iL as per their list
http://www.ebay.co.uk/itm/KYB-Suspen...kAAOSwl9BWKlO0
Just google for KYB Rear Coil Spring BMW 7 E32 750 i iL V12 300BHP Saloon 87 94 RA5021 or bmw e32 rear coil springs KYB or KYB RA5021 Coil Spring

[Spvrdx]

The ap lowering springs says it comes wit two front axle springs.. can I put them on the rear??

[shogun]

Maybe not so good idea to put front axle springs on the rear, I have never tried it. Do not even know if they would fit at all. Better use Rear Coil Springs

[Spvrdx]

Maybe not so good idea to put front axle springs on the rear, I have never tried it. Do not even know if they would fit at all. Better use Rear Coil Springs

Cool thank U shogun

Sent from my VIVO XL using Tapatalk

[shogun]

For those which want to have the LAD or EDC shocks repaired, a shop in Poland makes them, regeneration of LAD shocks, Nagengast http://www.nagengast.pl/regeneration-en.html
quote:
REGENERATION OF SHOCK-ABSORBERS




We repair shock-absorbers for most car types, motorcycles and other equipment.
We have been repairing shock-absorbers for 30 years now. Thanks to many years of experience (30 years) , highly qualified personnel and special equipment we are able to repair almost every shock-absorber. Each repair is covered by a written warranty (1 or 2 years).

As the only company in Poland we repair:

- shock-absorbers with the NIVO system in Mercedes and BMW cars

- shock-absorbers with EDC system (Electronic Damper Control) in BMW cars, E 31 ; E32 ; E34 ; E38 ; E65 ; E66 2 YEARS WARRANTY

- central shock-absorbers for all types of motorcycles

- shock-absorbers cooperating with the airbag in Lexus and Audi cars

- self-leveling shock absorbers (SLS) in Subaru Forrester ( I and II generation) , VW Passat cars

- shock-absorbers with the IDS CDC system ( electrical shock-absorber control) used in Ford Mondeo, S-Max, Galaxy and in Opel Vectra and Astra

- shock-absorbers with AMVAR system (electrical shock-absorber control ) used in Peugot 407 coupe,607, Citroen C6

- shock-absorbers with Magnetic Ride system, ( shock-absorbers with a special magnetorheological liquid used in Audi TT, R8)

[DSpoljaric]

Nice find Shogun!

[shogun]

SACHS Workshop Tip: Shocks and Dampers Leak.
Causes

Although a shock absorber or damper may appear to have a leak, this may not in fact be the case. A certain amount of "perspiration" is normal, and even necessary to lubricate the piston rod seal.
Never diagnose shocks and dampers after the vehicle has been driven in the rain - they should be dry.
Therefore:
Feel the shock absorber/damper with dry fingers. If your fingers remain dry, the shock absorber/damper is not leaking.If you are still not sure, wipe off the shock absorber/damper. Check again a few days later!

Oil mist residue on shocks and dampers
Cause: During every stroke, the piston rod carries a very small amount of oil from the working cylinder to lubricate the seal.
Consequence: If the shock absorber/damper was bone-dry, residue from this oil mist will be visible.
Please note: This is not a malfunction. Following extended periods of use, oil mist residue may be visible on around 1/3 of the container tube.

Shocks and dampers show clear traces of oil
Cause:
The piston rod seals are worn out due to:
Long use
Severe operational demands
Sand or road dirt
Consequence: Oil loss, and thus lower damping forces

Underbody sealant on shocks and dampers
Cause:

Underbody sealant or corrosion-preventive wax collects on the shocks and dampers.
Consequence:
It appears that oil is leaking.
Heat dissipates more slowly.
Please note: These substances do not belong on the shocks and dampers, so remove them! Accumulated road dirt is also often wrongly diagnosed as leakage.

Chromium layer on piston rod worn through
Cause:
Strong trapped stresses introduced to the shock absorber during installation
Misaligned attachment points.
Consequence: Wear on seal and piston rod guide, leading to oil loss and reduced performance
Please note: Always tighten the shocks and dampers only after the vehicle is standing on its wheels.

Piston rod damaged
Cause: The piston rod was gripped with pliers during installation, which damaged its surface.
Consequence:A rough piston rod surface causes the seal to tear, leading to oil loss and reduced performance. Please note:Use a special tool to hold the piston rod.

Here with pics https://www.zf.com/brands/en_de/sach...pers_leak.html

[dragon850]

I have a leaking rear LAD shock sitting in my garage. I will take it apart and attempt to rebuild it with new seals. Will document my adventures