Self Levelling Suspension
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Self Levelling Suspension
Can't remember where I read it now but seem to remember seeing something about all 635s manufactured for the UK after June 1988 having self levelling suspension? Can anyone shed any light on this please?
Re: Self Levelling Suspension
Good question & one I'm also interested in knowing the answer, as my 'new' 1989 Highline has/hasn't got SLS??!!feck wrote:Can't remember where I read it now but seem to remember seeing something about all 635s manufactured for the UK after June 1988 having self levelling suspension? Can anyone shed any light on this please?
Dave
Re: Self Levelling Suspension
You need an original owner's 1988/9 handbook, something which I'm desperately trying to find for you.....UKDaveJ wrote:Good question & one I'm also interested in knowing the answer, as my 'new' 1989 Highline has/hasn't got SLS??!!feck wrote:Can't remember where I read it now but seem to remember seeing something about all 635s manufactured for the UK after June 1988 having self levelling suspension? Can anyone shed any light on this please?
Re: Self Levelling Suspension
I read that all 88 and 89's have the SLS.feck wrote:Can't remember where I read it now but seem to remember seeing something about all 635s manufactured for the UK after June 1988 having self levelling suspension? Can anyone shed any light on this please?
Brian
-----------------------
1984 Graphite M635 - Project Graphite - Sold
1985 Polaris M635 - Polaris - Sold
1987 L6 Black/Lotus White - My Queen has a new home
1980 633csi - Gone but not forgotten
-----------------------
1984 Graphite M635 - Project Graphite - Sold
1985 Polaris M635 - Polaris - Sold
1987 L6 Black/Lotus White - My Queen has a new home
1980 633csi - Gone but not forgotten
Hmm,
Rear Suspension -- Self Leveling - Don Schmidek <[email protected]>
The '88 & '89 sixes have self leveling suspensions. The suspension consist of special shocks, hydraulic accumulators in the wheel arches, a pump and control system under the spare tire. There are also linkages connected to the rear torsion bars, etc. which sense the height of the car, plus piping, hoses, etc.
If your car rides very harshly or the height level keeps on changing, i.e. you hear the pump cycling frequently, the chances are that your accumulators are shot.
The good book states that the life of these may be as short a s 50,000 Km. Typically it is probably about 100,000 miles.
You can check out this problem by rocking the rear of the car -- push down on the rear bumper hard. If you get very little motion, you may the problem.
You can also check by bleeding the accumulators --- see below -- by disconnecting the big hose connection and seeing how much fluid runs out. If you get about 200-400cc from each accumulator, that suggests that they are defective. If both old accumulators were completely full of fluid, it indicates that the Nitrogen pressure charge had been lost. This may be due to the bladder braking or the Ni just leaking out.
To replace these, jack up the rear by the differential (use supports on the two sides via jack stands). Turn on the ignition (do not start the engine) to allow the system to normalize and depressurize -- for about 1 min. After that, just remove the two pipe connections to each accumulator (be sure to cover them, not to let dirt into the pipes) and let the fluid bleed off into a pan. Remove the old accumulators (3 nuts) and install new ones. Be careful not to miss-thread the fittings. Add fluid to the tank -- if you remove all the fluid before you start the process you will in fact rejuvenate the fluid -- all it takes is about 1 liter -- and you are ready to roll. Do not have to bleed the system -- but after you let the car off the stands, turn on the ignition and see if your car adjusts. Sit on the trunk edge, and see if it self adjusts. You can also measure the height from the ground to the bottom of the rear wheel arch -- it should measure about 27 inches. Finally, you should now get a little bouncing motion if you push down on the rear bumper.
Once done, you will find that your 6 rides comfortably over road irregularities as it was meant to, corners 200% better and no longer skitters in turns.
Now for the costs: Accumulator run about $130 each --- plus $10 shipping -- total $270. You may get quotes up to $270 each, but keep on shopping. Note that the retailers pay the wholesaler just $85 for each -- so there is plenty room to bargain.
You should use Pentosin 7.1 CHF as called out for hydraulic fluid -- costs is about $16 per liter. It is available in foreign car shops.
Happy driving.
The '88 & '89 sixes have self leveling suspensions. The suspension consist of special shocks, hydraulic accumulators in the wheel arches, a pump and control system under the spare tire. There are also linkages connected to the rear torsion bars, etc. which sense the height of the car, plus piping, hoses, etc.
If your car rides very harshly or the height level keeps on changing, i.e. you hear the pump cycling frequently, the chances are that your accumulators are shot.
The good book states that the life of these may be as short a s 50,000 Km. Typically it is probably about 100,000 miles.
You can check out this problem by rocking the rear of the car -- push down on the rear bumper hard. If you get very little motion, you may the problem.
You can also check by bleeding the accumulators --- see below -- by disconnecting the big hose connection and seeing how much fluid runs out. If you get about 200-400cc from each accumulator, that suggests that they are defective. If both old accumulators were completely full of fluid, it indicates that the Nitrogen pressure charge had been lost. This may be due to the bladder braking or the Ni just leaking out.
To replace these, jack up the rear by the differential (use supports on the two sides via jack stands). Turn on the ignition (do not start the engine) to allow the system to normalize and depressurize -- for about 1 min. After that, just remove the two pipe connections to each accumulator (be sure to cover them, not to let dirt into the pipes) and let the fluid bleed off into a pan. Remove the old accumulators (3 nuts) and install new ones. Be careful not to miss-thread the fittings. Add fluid to the tank -- if you remove all the fluid before you start the process you will in fact rejuvenate the fluid -- all it takes is about 1 liter -- and you are ready to roll. Do not have to bleed the system -- but after you let the car off the stands, turn on the ignition and see if your car adjusts. Sit on the trunk edge, and see if it self adjusts. You can also measure the height from the ground to the bottom of the rear wheel arch -- it should measure about 27 inches. Finally, you should now get a little bouncing motion if you push down on the rear bumper.
Once done, you will find that your 6 rides comfortably over road irregularities as it was meant to, corners 200% better and no longer skitters in turns.
Now for the costs: Accumulator run about $130 each --- plus $10 shipping -- total $270. You may get quotes up to $270 each, but keep on shopping. Note that the retailers pay the wholesaler just $85 for each -- so there is plenty room to bargain.
You should use Pentosin 7.1 CHF as called out for hydraulic fluid -- costs is about $16 per liter. It is available in foreign car shops.
Happy driving.
Self levelling suspension
I read somewhere that SLS was standard on US cars and an option for other markets.
Dave, that Highline hasn't got; and I expect the majority of UK cars won't have.
BTW, spark plugs are Champion double copper; always used 'em; never had a problem.
Sharkfan
Dave, that Highline hasn't got; and I expect the majority of UK cars won't have.
BTW, spark plugs are Champion double copper; always used 'em; never had a problem.
Sharkfan
Re: Self levelling suspension
Thanks Kevin,sharkfan wrote:I read somewhere that SLS was standard on US cars and an option for other markets.
Dave, that Highline hasn't got; and I expect the majority of UK cars won't have.
BTW, spark plugs are Champion double copper; always used 'em; never had a problem.
Sharkfan
Dave
Self levelling suspension
Has anyone ever seen a UK car with it fitted???
Re: Self levelling suspension
My brother-in-law has bought recently (about 2-3 months ago, after my boring him to death about the merits of a 635....) a 1989 F reg Highline which has (as mine) an LSD, rear window blind, electric bmw sports seats etc. Though he doesn't have cruise control, which I have on both my 635's.ron wrote:Has anyone ever seen a UK car with it fitted???
Anyway, according to his build details (I'm told) it has SLS.
Will investigate & report back!
Cheers,
Dave
Re: Self Levelling Suspension
SLS as fitted to my '85_635
The Pump assembly looks like a shoddy install, but my tech advised it is original kit. All appears to work OK..
The Pump assembly looks like a shoddy install, but my tech advised it is original kit. All appears to work OK..
Self Leveling question
Ron Carter, I read your post on how to replace the accumulators. Interesting reading. I have an 88 635CSI (5 speed) stick with self leveling suspension. I took the girl friend over to the local convience store for some smokes and while she was in the store I left the car running and put the car in neutral. After applying the parking brake I noticed that the car would adjust ride height every 10 seconds or so. It seemed to stop this movement after releasing the parking brake.
Here is my question. I was wondering if this is an indication of accumulator failure? I don't notice this happening while motoring down the street. I might say that the ride seems a little harsh, but the only thing I have to compare it with is a fairly new Acura MDX which could be described as "non-sporty" so not a fair comparison.
Please give me your thoughts.
John
Here is my question. I was wondering if this is an indication of accumulator failure? I don't notice this happening while motoring down the street. I might say that the ride seems a little harsh, but the only thing I have to compare it with is a fairly new Acura MDX which could be described as "non-sporty" so not a fair comparison.
Please give me your thoughts.
John