Oil required for 6.9 suspension

[Michel]

I am about to replace the 5 spheres on my 690SEL today and have purchased 6 litres of MB fluid (as well as the spheres ).

Can someone confirm this would be enough to flush the system as well?

 

[WGB]

I purchased my oil through Diesel Motors and managed to get them down from $57 per litre top $39 per litre.

Dropping the car flat and emptying it will require 5 litres for replacement.

If you take off the struts and empty everything it is 6 litres and if you want to flush it it will be more.

I tend to think trying to replace every last drop is a little overrated.

The most important bit is the bottom 500 mls in the reservoir and replacing the main filter and cleaning the other little filter in the high pressure side.

My system appears to be more precise with an oil change.

Bill

 

[Michel]

I purchased my oil through Diesel Motors and managed to get them down from $57 per litre top $39 per litre.
The most important bit is the bottom 500 mls in the reservoir and replacing the main filter and cleaning the other little filter in the high pressure side.
My system appears to be more precise with an oil change.
Bill

Would you or any one be able to tell me where those filters are? (picture maybe?)

 

[B13]

Yes pictures would be great - maybe this is what is conspiring to keep my 6.9 down (literally - its not lifiting). I knew there was 1 guaze filter up top which need periodic cleaning, but i didn't know there was another one elsewhere...

Never heard of the oil from Diesel motors, but it sounds extremely overpriced... I've used to Penrite for more than a decade without problems on my 2 6.9s and other SLS-based cars.

Ian.

 

[Michel]

Yes pictures would be great - maybe this is what is conspiring to keep my 6.9 down (literally - its not lifiting). I knew there was 1 guaze filter up top which need periodic cleaning, but i didn't know there was another one elsewhere...

Never heard of the oil from Diesel motors, but it sounds extremely overpriced... I've used to Penrite for more than a decade without problems on my 2 6.9s and other SLS-based cars.

Ian.

I paid $15 a litre from Euro Car parts..

 

[BAR]

Isn't this the same Total Oil that is used with the Citroen suspension.

If so any Citroen dealer or mechanic should have it.

 

[WGB]

I paid $15 a litre from Euro Car parts..

Well you get that.

There is a small paper cartridge filter in the reservoir which is revealed when you unbolt the valve from the top of the reservoir - which you will need to do anyway if you want to clean out the sump of the reservoir. (The oulet from the reservoir is positioned a few cm above the bottom so all the crap that escapes the paper filter sediments into this unused volume and is the most important area to clean out).

There is also a small compressed brass filter that is under the connection where the outlet from the pump meets the valve body on the top of the reservoir. These are unobtainable new but can be removed and cleaned in solvent and dried.

Do a search on w116.org. - S class has a pictorial with all the details.

The paper filter is available ex-dealer or ex-autohausaz.com.

Don't try and change the oil without cleaning out the reservoir - that's the most important bit.

Bill

 

[Michel]

Ok guys, I have a 690SEL on the hoist being worked on.....

Can someone tell me if the filter inside the reservoir (see item 3h in diagram) can be cleaned or must be replaced? Thanks

 

[B13]

Great pic thanks Michel.

I don't get something, where is the pickup? And how is the filter supposed to filter the oil if its up in the air high above the high-level marked on the dipstick?

By my mind, any crap in the system has to do a tour of the hydraulic system and come back to the control valve, then filtered then returned to the reservoir??? Sounds a bit dumb to me... the engine oil system makes much more sense, filter the oil before pushing it around the engine...

Just my 2c worth.

I.

 

[Michel]

Great pic thanks Michel.
I don't get something, where is the pickup? And how is the filter supposed to filter the oil if its up in the air high above the high-level marked on the dipstick?
By my mind, any crap in the system has to do a tour of the hydraulic system and come back to the control valve, then filtered then returned to the reservoir??? Sounds a bit dumb to me... the engine oil system makes much more sense, filter the oil before pushing it around the engine...
Just my 2c worth.
I.

I agree.....

I'm going back to the workshop
back in a couple of hours

 

[WGB]

THe paper one must be replaced and the brass one is cleanable (Not available new anyway).

Are you doing it yourself Michel?

If there is a delay getting the paper filter I would just change the spheres now and change the fluid later. You lose very little fluid just changing spheres and if any are buggared you will appear to make fluid as the total fluid volume in the system will decrease.

My plan of attack for what you are doing would be.
- depressurise system.
- remove reservoir
- remove all spheres ( Remembering the bolts for the RH front sphereunder the battery mount are accessible through the wheelarch)
- Lift the car up and down a few times with the hoist to pump as much oil out of the struts as possible while the speres are removed..
- clean out your reservoir with the valve removed from the top and the reservoir removed from the car. No matter how clean your oil looks on the dipstick the bottom 500 mls will be black tar.
- Replace what will be a black paper filter which is held by a spring clip arrangement with a new one.
- Remove the brass filter from the inlet port (mine was missing so I never did that step and as they are no longer available my system no longer has it).
- put your new spheres in with new copper washers after cleaning all the spilt oil away.
- replace the reservoir with two new lengths of low pressure hose and new clips as it is much easier to replace these with the reservoir out of the car.
- leave the high pressure hose from the pump into the valve body disconnected and the end pointing into the filler orifice on the reservoir and after putting 5 litres of oil into the reservoir start the engine for a few seconds until the pump primes itself.
- connect the high pressure pump line to the valve body on the reservoir.
- run the car until it is capable of supporting itself and check for leaks.
- go for a drive for 30 minutes on the high setting to get as much air out of the system as possible.
- top up the oil.

Bill

 

[WGB]

Great pic thanks Michel.

I don't get something, where is the pickup? And how is the filter supposed to filter the oil if its up in the air high above the high-level marked on the dipstick?

By my mind, any crap in the system has to do a tour of the hydraulic system and come back to the control valve, then filtered then returned to the reservoir??? Sounds a bit dumb to me... the engine oil system makes much more sense, filter the oil before pushing it around the engine...

Just my 2c worth.

I.

The pickup is not shown in that diagram but is an angled tube that comes out of the base at about a 45 degree angle and is extended inside the reservoir so that there is a small amount - about 500ml which does not circulate but allows solids to settle.

This tube is connected to the end of a length of metal tube which acts as a cooler via a rubber hose (I replaced with transmission hose of the correct diameter)and the other end of that cooler is connected to the input side of the pump by another length of rubber hose. These lengths of hose should be replaced and new non-sharp edged clips used so that they can be forgotton about for another 30 years.

The paper filter (3h in the diagram) is in the return line from the suspension and is supposed to catch whatever has returned from the suspension before it gets into the reservoir. (Serves to protect the pump which is more fragile than the usual engine oil pressure pump)

The sump arrangement allows what gets past this paper filter to settle undisturbed in the bottom of the reservoir which is where the surprising amount of black crap is usually found.

A possible major cause of pressure loss and sluggish functioning is the other small compressed brass filter which should be present in the valve body under the connection where the high pressure line connects to the valve body on the reservoir. This is the one that was missing on my car but others have reported to have been clogged.

I would clean this in thinners or such-like and then blow with compresssed air until dry before replacing.

Bill

 

[Michel]

Are you doing it yourself Michel?

No, my mate Morris at Morris Performance

My plan of attack for what you are doing would be.
- depressurise system.
- remove reservoir
- remove all spheres ( Remembering the bolts for the RH front sphereunder the battery mount are accessible through the wheelarch)
- Lift the car up and down a few times with the hoist to pump as much oil out of the struts as possible while the speres are removed..
- clean out your reservoir with the valve removed from the top and the reservoir removed from the car. No matter how clean your oil looks on the dipstick the bottom 500 mls will be black tar.
- Replace what will be a black paper filter which is held by a spring clip arrangement with a new one.
- Remove the brass filter from the inlet port (mine was missing so I never did that step and as they are no longer available my system no longer has it).
- put your new spheres in with new copper washers after cleaning all the spilt oil away.
- replace the reservoir with two new lengths of low pressure hose and new clips as it is much easier to replace these with the reservoir out of the car.
- leave the high pressure hose from the pump into the valve body disconnected and the end pointing into the filler orifice on the reservoir and after putting 5 litres of oil into the reservoir start the engine for a few seconds until the pump primes itself.
- connect the high pressure pump line to the valve body on the reservoir.
- run the car until it is capable of supporting itself and check for leaks.
- go for a drive for 30 minutes on the high setting to get as much air out of the system as possible.
- top up the oil.

He has done all of that, but because it is done as a bit of a favour, he didn't do it non-stop.
He has all spheres removed and the rear are replaced, tomorrow will finalise the rest

I'll keep you guys posted

 

[WGB]

New spheres and new oil and clean filters - I think you will be astounded at the difference - I was.

My guy at Diesel Motors said I was wasting my time and money as it should never need changing but after seeing the black filter and the crap in the bottom of the tank as Styria and several others have mentioned I'm pleased I have done it.

I am still considering changing the front struts on my car to get the best I can but that expense will have to wait.

Bill

 

[Michel]

New spheres and new oil and clean filters - I think you will be astounded at the difference - I was.

I had to change them....
Three of them simply became hard as rocks...So I decided to change the lot. And I want to take the car this Saturday to the Shannon's Eastern Creek Day...

Digressing....

Morris said the oil was pretty clean.....
And that reminds me that Styria must have changed it for me at some stage when he did some maintenance work on the 690SEL

 

[WGB]

The problem is that they don't seem too bad but having replaced worn (but not worn out) shockies on 126's and 124's I know there is a tremendous potential improvement in handling which has been reported by S class with his trusty rusty Blue car.

Time will tell - I have a few other jobs to do before that and anyway my 6.9 is starting to handle a lot better with every "improvement".

Bill

 

[Michel]

All done.....

What a pleasure to drive.... although the weather is not nice in Sydney (showers...) it was fun testing the 690SEL this morning.

Morris is till doing some minor stuff to it and I'll pick it up later this arvo...

Thanks for all your help....

 

[Michel]

What a difference....................

I just drove it back and I am ECSTATIC....

I truly had forgotten how wonderful the 6.9 suspension is....

 

[WGB]

It always makes me want to head for the biggest widest traffic control strips at the speed limit and watch the traffic melt behind you while you hardly notice the bumps at all.

You are wise to do all five at the same time - it gives better balance.

Bill

 

[Michel]

It always makes me want to head for the biggest widest traffic control strips at the speed limit and watch the traffic melt behind you while you hardly notice the bumps at all.

You are wise to do all five at the same time - it gives better balance.

Bill

Another surprising bit is that the car sits higher (now normal) than what it was before I replaced the spheres... and I did not make any adjustments...