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Thread: LAD/self levelling elimination + LAD shock repair info

  1. #76
    Join Date
    Jan 2005
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    11/88 E32 750iL+98 E36M3
    Just got an email from Australia from a E32 740iL owner who had his shocks repaired last year and now apparently one shock was leaking again. Told him to remove the hose and stick something inside the accumulator, short time later the reply:
    "Did the dowel test today on my car's left accumulator (the side with the suspected leaky Sachs shock). Dowel fell straight through and went CLUNK against the opposite side of the chamber. No resistance at all."

    This exactly confirms rv8flyboy's statement on Bimmerboard:
    Before u hit yourself up as a bad seal installer...
    I been fighting leaking seals for a while myself, here is some food for thought. The shocks are not supposed to have fluid on top of the piston, if fluid is leaking at the top of the shock, you have fluid leaking past the piston, eventually the space fills up and is squeezed past the top shock rod seal whenever the piston needs to move up. Some is also blown back down past the piston seal when external forces, such as the springs, lift the rear up. This is due to the single acting design of the piston cup. For example, when u get out of the car, the backend wants to raise up, the trapped fluid is now compressed against the rod seal. So, if the piston is not fixed the leak will come back. How long you may ask, well that depends on the amount of leakage, for some it may be weeks, for others maybe years. Other thought... how are your accumulators, found mine shot, the back end very hard to push down, if at all, by hand. If you drive around with fluid logged accumulators every time you hit a bump or dip, the hydraulics will get a tremendous pressure shock. The fluid cannot go back quick enough through the ride height regulator valve. The compressed hydraulic fluid has to go somewhere so the rubber seals become the only place where there is compressibility, ergo, yer seals are forced to deform beyond their capabilities and eventually will blow out. you can change seals till yer blue in the face, if you don't address either the leak past the piston in the shock, or the accumulators, yer leaks are bound to come back. I did an experiment with a shock that leaked from the top and one that did not. I swapped piston and rod between them, left top seal in place, and sure enough after about a week or so, the formerly good top seal developed a leak, the shock with the top leak quit leaking (so far) from the top. on the one that did not leak from the top anymore, I blew the bottom seal, the one inside the 32 mm nut, a little while later, which necessitated a tow home. This is how I found out that every accumulator I had acquired over the years has empty. Just stick a small dowel through the center hole, if it goes in far enough to reach the far end, yer bladder is shot. And if both yer bladders are shot, the seals in the shocks probably wont be far behind for the reasons stated above. just my $0.05 worth. 750IL 1990 (9/89) Black, 90K, from this thread http://www.bimmerboard.com/forums/posts/1261417
    Shogun tricks and tips for the E32 series are HERE!

  2. #77
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    11/88 E32 750iL+98 E36M3
    Removing the "SUSPN LEVELING" warning message youtube instructions
    This video describes the method of disabling the height-sensor on the rear suspension of a BMW E34 M5, this eliminating the "SUSPN LEVELING" check control warning message. This method may also work on the E32 7 series equipped with Self Leveling Rear Suspension (SLS).
    https://www.youtube.com/watch?v=nwUblJyhPLs
    Shogun tricks and tips for the E32 series are HERE!

  3. #78
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    11/88 E32 750iL+98 E36M3
    More info
    specific for the BavAuto elimination Kit pdf file. http://www.bmwe34.net/E34main/Mainte...34ElimKits.pdf
    more SLS/LAD information here: http://www.bmwe34.net/E34main/Mainte...uspensions.htm
    Shogun tricks and tips for the E32 series are HERE!

  4. #79
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    11/88 E32 750iL+98 E36M3
    As I got an inquiry how to delete SLS, small update: on my website are detailed instructions http://twrite.org/shogunnew/upgrades...adreplace.html

    In case someone has detailed instructions to delete EDC I and EDC III system (incl. SLS on rear), please post here, what has to be replaced.
    Shogun tricks and tips for the E32 series are HERE!

  5. #80
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    Jan 2019
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    1996 BMW E34 Touring
    Hi. Thanks for the topic. Sorry for my english it's not perfect

    I have a BMW E34 Touring 1996 520i with nivo. My rear left shock is leaking and my regulator is leaking as well. I know that I can regenerate my shocks in nagengast (i live nearly on the same street) but they are not doing regulators so I don't want to stay with one thing leaking. I'm sure that I want to eliminate NIVO. I have a few questions:

    1. Do I have to change rear springs? If yes, why?
    2. Can I remove everything from the nivo system (figure 3) http://www.bmwe34.net/E34main/Mainte...34ElimKits.pdf
    3. My nivo pipe is leaking as well in the middle of chassis. In the place where it runs parallel to brake pipes. Where is the best place to make a loop of the nivo pipe?
    4. What do you recomend for that kind of loop?
    5. In my opinion I have to change shocks, Shock absorber sockets, rubber things above shocks and plastic shock protection things. Am I right?

    Thanks a lot.

  6. #81
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    11/88 E32 750iL+98 E36M3
    1. Do I have to change rear springs? If yes, why?>>> LAD/Niveau springs after softer than standard springs

    2. Can I remove everything from the nivo system (figure 3) >>>>>yes
    3. My nivo pipe is leaking as well in the middle of chassis. In the place where it runs parallel to brake pipes. Where is the best place to make a loop of the nivo pipe?
    4. What do you recomend for that kind of loop?

    Instead of a loop you can modify the power steering pump, which is originally a dual pump. Modify it to single pump. Easiest is to modify from dual pump to single pump by just removing the spring and valve for the self levelling section of the pump, then the pump cannot build up pressure in that section. Or install a single pump instead of a dual pump. If you keep the original dual pump, you have to make a loop from outlet of the pump to the Pentosin return pipe of the Pentosin container/reservoir.
    Modification of the double pump into single pump, see pictures here in post # 17 http://www.7-forum.com/forum/showthr...pe#post2526319

    5. In my opinion I have to change shocks, Shock absorber sockets, rubber things above shocks and plastic shock protection things. Am I right? >>>yes, see my post # 8 with details for E34 http://www.7-forum.com/forum/showthr...pe#post2526319
    also shock mounts have to be replaced.

    If your Niveau regulating valve is leaking and you want to keep the system, buy a regulating valve for the E38. That fits, but the lever on the side has to be changed against the old from one the E34/E32 regulating valve, as the shape of the E38 regulating valve lever is different.

    Tandem pump LAD section delete, done by someone in Germany: remove the large + plug in center on drive side, remove then there the spring and a smal pin with holes, get a plug with thread M18x1,5 to replace the old + plug. Done. The connection originally for the LAD line can be plugged with a bolt with thread M12x1,5, picture where the new plug is, the one new, left side next to the drive
    Attached Images Attached Images
    Last edited by shogun; 02-11-2019 at 06:47 AM.
    Shogun tricks and tips for the E32 series are HERE!

  7. #82
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    Jan 2019
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    Poland
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    1996 BMW E34 Touring
    Thank You very much!

    I think I'll keep my dual pump untouched, because I want to keep all the nivo elements for the new owner of a car. In the future I want to give him simple informations about getting back Nivo.

    What do you recommend for a loop? Can it be a copper tube from which the pipes are made of?

  8. #83
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    11/88 E32 750iL+98 E36M3
    Here are 60 pages LAD info, on page 6 is a cross section of the pump https://www.yumpu.com/en/document/re...ion-pdf-e38org
    The loop you can do anywhere convenient to you, feed line to return line. Just make sure the loop hose/tube can stand a pressure of 130 bar ! Original hydraulic lines with reserve are laid out for 180 bar bursting pressure.

    Here pictures of the tandem pump from my 750 we repaired in 2008 http://www.bimmerboard.com/forums/posts/526913/ http://www.bimmerboard.com/forums/posts/527187
    Shogun tricks and tips for the E32 series are HERE!

  9. #84
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    Jan 2019
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    1996 BMW E34 Touring
    I think I don't understand two things. Could you please explain it maybe differently...?


    "The connection originally for the LAD line can be plugged with a bolt with thread M12x1,5, picture where the new plug is, the one new, left side next to the drive"




    "Original hydraulic lines" - could you give me the number of this part? or Please show me the place on a diagram where is it?

    Thank You.

  10. #85
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    "The connection originally for the LAD line can be plugged with a bolt with thread M12x1,5, picture where the new plug is, the one new, left side next to the drive" >>>>this is only when you want to eliminate all LAD parts starting from the power steering tandem pump and modify the double pump to single pump. So you remove the spring from the one port with + plug and replace it with a simple bolt = tandem pump/LAD pump no longer functioning. Instead of the LAD discharge line from the pump you install a M12x1,5 in the pump , so instead of the LAD line a plug to close the outlet on the pump.
    In case you do not eliminate inside the tandem pump the function of the pump for LAD, NEVER close that with a plug, lways make a return line, otherwise the pump will be destroyed.
    But as you said, you want to keep the pump as is in original condition and will not touch it, forget this, then you must make a return line from outlet pump to the reservoir.

    "Original hydraulic lines" - could you give me the number of this part? or Please show me the place on a diagram where is it? >>> see realoem, for example all the crimped hydraulic hoses in the complete LAD system, different part numbers, different sizes, but the system pressure is 130 bar http://www.realoem.com/bmw/select.do
    Shogun tricks and tips for the E32 series are HERE!

  11. #86
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    11/88 E32 750iL+98 E36M3
    when it bounces = no dampening effect, then the pressure accummulators are dead, no gas inside. You can test them, disconnect the hoses from the pressure accummulators and stick a long drill rod to poke inside the accumulators. On the old bad one the drill rod will go inside and might touch the deepest point of the accumulator = there is no gas inside anymore
    Attachment 657264
    On the new accumulator the rod will go only in about the length of the neck. Not only that but looking into the new accumulator one could clearly see the bladder.
    Attachment 657265

    Yes, LAD system uses Pentosin
    and here I cut a LAD bomb to explain the system https://www.youtube.com/watch?v=ZWmQ...el&gl=DE&hl=de
    Attached Images Attached Images
    Shogun tricks and tips for the E32 series are HERE!

  12. #87
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    11/88 E32 750iL+98 E36M3
    Today we checked the pressure accumulators aka SLS bombs on a Alpina B12 E32 equipped with EDC and the rear shocks with EDC/LAD. The member of our wrenching group complained about very hard rear sus. So we drove the car on the pit and then lifted it with a quick jack which he recently bought, so the wheels were in the air = shocks cpl. expanded = pressure in the system in the rear low. Then we disconnected the pressure hose going into the bomb from the shock, not too difficult, only very little loss of Pentosin as the shocks are cpl. expanded. Then we stuck a small screwdriver into that hole into the bomb as shown in above pics, the screwdriver went straight thru to the other end, dead, tested the other one, also dead. That is the easiest and best method to really test the bombs.
    As we had stock of new bombs, we changed them both, rear wheels have to come off to have access from rear wheel house and another person from below the car to assist to remove the bolts and nuts. Took us in total 4 hours only incl. lunch break, lucky that nothing was corroded and the pressure hoses could be removed w/o problem. Have seen other cars were we had to remove the complete shock with the bomb attached to separate bomb and shock in a vice like shown on this page
    http://bmwe32.masscom.net/sean750/LA...cumulators.htm
    A huge difference in driving comfort after changing the bombs.
    Shogun tricks and tips for the E32 series are HERE!

  13. #88
    Join Date
    Jun 2011
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    NYC & Long Island & So FL
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    '93 740il '84 633Csi
    Shogun,
    I had my LAD replaced years ago so this question is for the rest of the community: With Bavarian Auto NLA, is there a parts list of items that can be obtained from other suppliers to do the elimination?
    Thanks,
    Ken

  14. #89
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    11/88 E32 750iL+98 E36M3
    It is all mentioned in this thread, read from start, no need for parts from bavauto, any other shop can deliver shocks, springs, shock mounts.

    PROCEDURE from bavauto:
    1. Disconnect the hydraulic hose, at each side, running between the rear shock and the accumulator(mounted to the rear inner fender well), at the accumulator.
    2. Remove the rear shock and spring assemblies complete with the upper mounts and hydraulic hoses.
    3. Remove the accumulators and the hydraulic hoses running from the accumulators to the distribution block. Remove the hydraulic hose running from the regulator to the distribution block.
    4. Disconnect the attaching lever and connecting link from the sway bar and the hydraulic regulator valve.
    5. Disconnect the pressure and return lines (coming from the engine driven pump) from the regulator and remove the regulator.
    6. The pressure and return hoses must be rerouted and connected together. This can be done using a union connector (M10 x 1.0) at the ends of the hoses where they have been disconnected from the regulator or further forward closer to the pump. The connection can be done at (Figure 1 “B”) using one of the existing union connectors and gently bending the hose and pipe (#1 & #2) and using the union to connect them together. The hoses CAN NOT be simply plugged. This will damage the
    hydraulic pump, which also supplies the power steering and power brakes.
    7. Assemble the new springs, shocks and upper mount hardware from the Self-leveling Elimination Kit.
    8. Install the Spring/shock assemblies into the vehicle.
    9. Start the engine and check for leaks at the union of the pressure and return lines.
    ------------------
    so basically wherever you want between engine bay and regulating valve on the rear axle make a connection between feed and return line, the Pentosin MUST circulate always.I have seen even someone routing it back from outlet power steering pump into the Pentosin container, self made hydraulic pressure hoses/pipes. Just remember!: The power steering pump has a pressure of 130-140 bar, so a 'garden water hose' will definitely not last long.

    possibilities
    plug the regulating valve output line towards rear of the car = bombs/shocks, fix the regulating valve in the position that the feed from power steering pump goes directly back into the return line in the valve. In case the regulating valve is leaking, others just make a u-turn line before the regulating valve from feed to return line.
    Third possibility is to remove from the double power steering pump from the section for LAD the piston, so that one part of the power steering pump is no longer working, then only the power steering pump section works. See picture in my post #81, that pic is from an M70 power steering pump.

    Remove bombs and hoses between regulating valves and shocks, if you want, see pics in below link
    Parts needed to replace: standard shocks and springs (LAD springs are softer) shock mounts, pics are on my website under upgrades http://twrite.org/shogunnew/upgrades...adreplace.html
    Last edited by shogun; 09-01-2019 at 07:06 AM.
    Shogun tricks and tips for the E32 series are HERE!

  15. #90
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    11/88 E32 750iL+98 E36M3
    not too difficult to repair the regulating valve. The E38 regulating valve and the E32 regulating valve are identical, except the lever has a different shape. That is the E32 valve and you see the lever http://www.bimmerboard.com/members/e...agem%20126.jpg
    I already have repaired some SLS regulating valves, some pics on my website under systems.
    Basically a few O-rings and seals, here a pic of such a seal kit from someone on a German forum, hope you can see it without login https://www.7-forum.com/forum/album.html?albumid=7463
    here more pics I posted of the disassembled valve http://www.bimmerboard.com/forums/posts/508927/
    read the cpl. thread there, there are some dimensions mentioned by Jeff http://www.bimmerboard.com/forums/posts/511327
    http://www.bimmerboard.com/forums/posts/509799
    visit a hydraulic repair shop, they can help you with the proper seals and o-rings, nothing special.
    Important is that you mark the position of the lever installed on the valve before you disassemble it, otherwise it is not so easy to find again the zero position
    Shogun tricks and tips for the E32 series are HERE!

  16. #91
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    91 850i 95 740i
    egbqljehrgbq;rp.jpg Hello just want to add a picture of the lines looped in the front left wheel well. Originally I was going to make the loop but my local parts store had a 6 inch section already made for $7; As opposed to $35 for 25 foot of line and a few bucks for fittings. A little section of line premade (3/16" line m11 fittings) is definitely available at any parts store in America. As previously mentioned you could just connect them with one of the already used unions, however I went with this route because of how corroded everything was and I would of been fine with cutting the lower lines that aren't needed anymore. Shogun feel free to include this picture anywhere you seem fit. Your knowledge is much appreciated.

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