Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1088

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1130

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1179

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1195

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1214

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1225

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1299

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1310

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1386

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1485

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1510

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1547

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1578

Deprecated: Function create_function() is deprecated in /nfs/c01/h01/mnt/10022/domains/forum.w116.org/html/Sources/Subs.php on line 1589
suspension wont rise

Author Topic: suspension wont rise  (Read 3448 times)

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
suspension wont rise
« on: 09 September 2016, 10:54 AM »
I've read everything I can, and followed procedure, but still cant get suspension to rise.  The entire system has been removed, refurbished and re-installed. Pump was bled into tank, good stream of fluid.  The control disc is all the way CW to the stop, which is N position.  I raised car and ran, the dash light was red and is now not on.  If I pull the knob out to other positions the light turns on.  Lowered the car, and have run at 2000 rpm for @10 minutes, still no rise anywhere.  The level in the tank doesnt seem to be dropping at all.

From what I read in manual,the 5th cylinder needs to fill up to pressure, then it releases the valve to fill all the rest.

Any tricks out there that I could try? 

Any particular spot I should crack a line to see if fluid is flowing?  Control valve or at accumulators?
« Last Edit: 09 September 2016, 10:58 AM by rumb »
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #1 on: 09 September 2016, 11:53 AM »
Hi Robert

If you have the bleeder valves at the accumulators (under battery tray you can access the front), then I would start there and bleed some fluid off.  Be careful as I am sure you know there is extreme pressure present here!

If the system is "up" and running you will get return flow back into the reservoir, so look inside the tank with a flash light and see if you see return flow.

also check your leveling valve arms.  when the suspension is down, the valve must be in the "filling" position, thus the arm must point towards the ground at roughly 45 degrees.  This signals the valve to send fluid to the strut to "pump up".  Once level the valve cuts out.  I think your problem lies with the leveling valve, check the arms and connection to the sway bar first.
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #2 on: 09 September 2016, 12:17 PM »
I have the earlier version without the bleed valve. 

I think you have the leveler valve backwards, up is fill, down is lower.  (at least for the front one)

When the car is down, the lever is up. If you jack the car up, so the wheel hang it is down.


How long should it take to fill an empty system?
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #3 on: 09 September 2016, 12:57 PM »
Sorry yes you are correct I had the arm position backwards.  So when the suspension is down, the arm will be 45 degrees towards the sky, not ground.  This is the "signal to fill" to the valve.
On my 6.9 if it is completely down, then all that is required is start up and idle (no revving), then it takes about 30 seconds.  Slow at first, then rapidly, so I would say from 30 sec to 45 sec, it does the rising part.
Once cut - out pressure is achieved (in the pressure regulator) then the flow from the pump is reversed back into the tank.  have you checked the little gold filter inside the pressure regulator?  Sometimes they can be clogged with crud.
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #4 on: 09 September 2016, 03:26 PM »
where is the gold filter located?
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #5 on: 09 September 2016, 06:07 PM »
Look at the pressure regulator. There is a 12mm hex bolt pointing towards the firewall. Remove this bolt and deep inside this channel sits the filter. You must remove the filter by a pick or suck it out with some hose and syringe. Careful as these are NLA. Give it a few blasts of air and carb cleaner. Also replace the o ring on the shaft before install.
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #6 on: 10 September 2016, 03:24 PM »
Cleaned some gunk out of there, no immediate change, though I did not run engine very long.

« Last Edit: 10 September 2016, 04:43 PM by rumb »
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #7 on: 10 September 2016, 04:42 PM »
After reading everything I could on M1oo site, I think I will take the control valve and pressure regulator off and take apart and clean everything.

Since I was able to fill the 5th cylinder and turn the light off, I suspect that there is something keeping the fluid from being directed to the leveling valves.

Poor car has sat for so many years, it's best not to trust anything.  I can always swap from the parts car also.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #8 on: 10 September 2016, 05:32 PM »
Not a bad idea. Could be a tiny bit of crud causing one of the check ball valves not to seat properly. Make sure you keep track of the balls in the height control switch.  The top ones are bigger than the bottom ones.  There is also an o ring between the pressure regulator and the height control switch.
« Last Edit: 10 September 2016, 06:36 PM by daantjie »
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #9 on: 16 September 2016, 02:44 PM »
Today I took apart and cleaned the switch and the pressure regulator.

The big screw on the top of the switch was stuck and I managed to break it off.  >:(

Got the other one off the parts car, it was easy to get that screw off, so I cleaned that one out.

Put everything back on the car and not much difference.  After I shut the car off if I moved the switch I could hear clicks and fluid moving somewhere in the system.

Next step is to change pumps.  I put the one from the parts car on originally.  The original one I at least know it was working previously,so maybe the pump I used is not supplying enough pressure even thought there is a good flow of fluid from it?

'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #10 on: 16 September 2016, 04:53 PM »
Are you getting return flow back into the reservoir?
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #11 on: 17 September 2016, 10:22 AM »
How would I tell?  With the lid off I never noticed any disturbance in the fluid.

I found that strange, as you would think the fluid being pumped would at least be re-circulated somehow.

What line is the return line into to regulator?


Would no return flow be indicative of bad pump?
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #12 on: 17 September 2016, 10:38 AM »
The return flow can be hard to see but if you shine a strong light into the fill hole and onto the bottom of the filter you should see a slow trickle.
If the warning light goes off you should have reached cut out pressure and then the reverse flow happens.
Usually the pump is the more robust part of the system.
Some guys rap the large bolt on the pressure regulator with a soft hit hammer to shock loosen potential dirt inside the regulator but I would be hesitant to try this.
Maybe strip out the top bolts on the pressure regulator and clean the check valve out. They can be super tight though and of course you need fresh sealing washers for assembly.
Daniel
1977 450 SEL 6.9 - Astralsilber

daantjie

  • W116 Addict
  • ****
  • Posts: 1,966
  • W116 Enthusiast
  • Location: Vancouver, BC, Canada
Re: suspension wont rise
« Reply #13 on: 17 September 2016, 11:31 AM »
Edit
« Last Edit: 17 September 2016, 11:43 AM by daantjie »
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

  • W116 Addict
  • ****
  • Posts: 1,523
  • MB Enthusiast
  • Location: Fort Collins, Colorado
Re: suspension wont rise
« Reply #14 on: 17 September 2016, 01:24 PM »
Success!  My son came by so I showed him the car.  I had noticed that the back was beginning to have some bounce in it if you bounced the rear fenders. Anyway, started the engine and bounced the 4 corners a bunch, and first the back rose, and then more bouncing got the front to come up.  Perhaps moving the valve back and forth (loading and unloading the system) cleared thing out somewhere in the system.


Need to finish the brake job on my 300SE that is on jacks behind the 6.9 on Monday or Tuesday after parts arrive and then I can go on my maiden voayage.

 :) :) :)


PS anyone have a spare screw that goes on the top of adjuster valve?
« Last Edit: 17 September 2016, 02:22 PM by rumb »
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550