George, I was thinking of you when i was doing this

[Bill R.]

job.... Lad fun...
http://www.bimmernut.com/~billr/images/Ladfun1.jpg
http://www.bimmernut.com/~billr/images/Ladfun2.jpg http://www.bimmernut.com/~billr/images/Ladfun3.jpg http://www.bimmernut.com/~billr/images/Ladfun4.jpg

[winfred]

were you whistling zippady doo daa outta your ass? :D

[winfred]

i did a new aux fan and radiator/thermostat in a turd 91 535, charged the battery and diagnosed a dead brushpac/replaced fac clutch in a nice 95 525im, helpled chuck (the other wrench at our shop) with his days project of fixing several melted wires in a turd e38 and replaced the heater hoses on a turd 740 volvo

[Bill R.]

car all its life... unfortunately the owner had me check and its a nikasil motor with a nice miss to it... they just replaced the computer and one coil and that fixed the worst part of the miss... but its still got a pretty bad idle...
He wants me to do a leak down on it...I asked him if he reeally really wants to know :)






were you whistling zippady doo daa outta your ass? :D

[winfred]

spray some carb cleaner below the throttle body after a cold start, these bastard gaskets are dropping like flys around here, the one i got that the dealer said the nic was shot on just needed a fuel pump, 20 psi just aint enough and thats all it had left in it


car all its life... unfortunately the owner had me check and its a nikasil motor with a nice miss to it... they just replaced the computer and one coil and that fixed the worst part of the miss... but its still got a pretty bad idle...
He wants me to do a leak down on it...I asked him if he reeally really wants to know :)

[Bill R.]

auction.... the local mercedes dealer had dumped it off at the auction to be sold..I suspect they already checked it and dumped it to get rid of it...






spray some carb cleaner below the throttle body after a cold start, these bastard gaskets are dropping like flys around here, the one i got that the dealer said the nic was shot on just needed a fuel pump, 20 psi just aint enough and thats all it had left in it

[winfred]

id say they dumped it cause it's 12 years old, unless it's something real special the local dealers just flush them through the friday auction and get whatever, at which point we buy and resell :D

[632 Regal]

intake gasket, I doubt the dealer took effort on a trade in car and just wants it off his lot.

[George M]

Hi Bill...hehehe...yeah know that drill...not too bad...except for removing or should say replacing the electric rear seats if so equipped.
Wish my muffler looked that good :-)
Don't work too hard my friend,
George

[winfred]

yea really who designed that pita


except for removing or should say replacing the electric rear seats if so equipped.

[Jr ///M5]

On one of the 7 series sites, it showed someone rebuilding one of those shocks. At least replacing the O-ring seals that cause them to leak from the top and down the shock. I've always wondered if it could be done and I'm tempted to try it on the M5, as the right rear has started to seep. I've also heard of guys replacing the expensive hydraulic shocks only to have them start weeping again.
That makes me think the accumulators could have been at fault. I know a little seepage is normal.

Can I ask what the symptoms were for the LAD you were servicing Bill?

Jr

[Bill R.]

It had that lowrider kind of ride that happens when the accumulators go bad, I also think that thats what caused the upper struts mounts to go also... A normal shock functions as a cushion to slow down the movement.. The lad struts primarily are hydraulic lifts , so its like sitting on a solid strut which makes the rubber upper strut mount take a lot of punishment.. The nitrogen gas bag inside the accumulator or bomb acts allow the fluid in the strut to compress that gas bag and give the strut some give on compression, so it acts more like a regular shock... I saw the writeup on the m5 board about the guy thats rebuilding them..Personally until they were leaking quite a bit i wouldn't even consider it.. But thats just me.








On one of the 7 series sites, it showed someone rebuilding one of those shocks. At least replacing the O-ring seals that cause them to leak from the top and down the shock. I've always wondered if it could be done and I'm tempted to try it on the M5, as the right rear has started to seep. I've also heard of guys replacing the expensive hydraulic shocks only to have them start weeping again.
That makes me think the accumulators could have been at fault. I know a little seepage is normal.

Can I ask what the symptoms were for the LAD you were servicing Bill?

Jr

[George M]

Bill said it correctly as usual Jr...only thing I will add is per your comment, I do believe a strut that is prone to weepage....which even the best are...will weep or emit more pentosin when the accumulator(s) goes bad for precisely the reason Bill stated the upper mount will prematurely fail with spent bombs. When the bombs lose their compressibility this will dramatically increase seal pressure when driving. The struts don't see sustained pressures but pressure spikes due to road disturbances. Without healthy accumulators as a buffer to the unforgiving nature of incompressible fluid, much more force is imparted to the strut seals. The leakage you see maybe residual leakage from when you drive the car if your accumulators are bad. Believe Jr you know the telltale for bad accumulators...a bouncy ride. If your rear suspension is original and as I recall your beautiful M5 is around 100K in mileage...you will not believe how good the suspension will feel if you replace your accumulators. Typical life for a LAD strut is about 120k miles. Mine where replaced at 120k miles and 130k miles respectively.
HTH,
George

[Jr ///M5]

You replaced the hydraulic strut along with the accumulators? I was thinking along the same lines, but wanted to tear into the struts just for the sake of curiosity, just to see if it could be rebuilt.

My car still rides fine, but I'm sure the gradual degradation of the system after all those miles could certainly have an effect.

I did notice this.....When I hit the deer a couple years ago, we loaded the M5 up on the tow truck and when driving the 5 short miles to the BMW dealer, I could see the ass end of the M5 bouncing easily as we drove down the freeway. No pressure on the LAD system and the springs take over, since they aren't like regular springs, they really show how soft they are. You would think it would be easy to bounce when the car is at rest in the garage, but it's not.

Maybe in March or April, I'll tackle the rear on the M5....the accumulators aren't bad (price-wise) but those hydraulic shocks are about $400 each...and that's with the deep discount from u-know-who....=)

Thanks for the insight guys,
Jr

[George M]

on my part my rear suspension was worked on in three stages...the PO who didn't turn a wrench had the car worked on by Bavarian Auto in Michigan and had the driver side strut replaced...didn't do both at the time for economics :-) When I bought the car the passenger side by now was leaking and I changed that one. And lastly a few thousand miles later I changed the accumulators which made a world of difference. A point of clarification on what you wrote about your M5 bouncing on the trailer. Your comment about no pressure being on the LAD and springs taking over isn't quite accurate. You are correct the springs are soft by nature but this is because the LAD hydraulic pressure is always present and preserved for example by a check valve within the regulator valve that maintains the ride height of your car even with the ignition off in a static condition. Otherwise Jr, the rear of the car would significantly sag when the engine was off overcoming the weight of the car. The hydraulic pressure holds the rear of the car at the correct ride height. At 100k miles and if you detected some bounciness, likely your accumulators are near the end of their life which is quite common for this mileage. What you perceive to still be a good ride will go from good to superior when you change your accumulators as loss of ride quality is incremental over time as you say. Real bad accumulators however will feel like you are riding a pogo stick...literally...which is kind of fun when you hit some decent bumps at speed but not what the engineers intended..lol.
Cheers,
George