Draining SLS Question - 80 TD - PeachParts Mercedes-Benz Forum

tobybul · #1 04-19-2008, 04:51 PM

I just replaced my accumulators. It was good to know the old ones were actually bad (Bladder was nowhere to be felt inside and spheres where filled with oil). I know this topic has been discussed once or twice but... if it not too much trouble, I'd like ask again what is the best way to drain the oil out of the system. I have read some do it with the engine running and some just gravity drain.

I have the car jacked up right now but also sitting on ramps. So the rear is up high right now. I got about a 1 to 1-1/2 qts of oil that pretty much came out of the spheres.

The new spheres are now installed. I opend the bleed valve from the controller but only about 2 drops came out. The reservoir is about half full. I'd really like to remove as much of the old oil as possible.

Can the oil be drained with the car level and the engine not running? Thanks for the help.

mobetta · #2 04-19-2008, 11:03 PM

this is what I'd do.

compress the struts- do this w/ the lines from accumulator off, so the old oil doesnt go back into them. lower car onto ramps, push down/ jump on bumper, etc to get old oil out.

next unhook the return line- where the filter is on the reservoir, and re-rout to a catch can. unhook the level arm from the valve, or jack up to nuetral position, where oil will be returned to reservoir, not pushed to struts. run engine , and add new oil as the old is pushed out. when clean oil comes out return line, shut off, hook all lines up, and bleed.

tobybul · #3 04-20-2008, 12:30 AM

Quote:

Originally Posted by mobetta

this is what I'd do.

compress the struts- do this w/ the lines from accumulator off, so the old oil doesnt go back into them. lower car onto ramps, push down/ jump on bumper, etc to get old oil out.

next unhook the return line- where the filter is on the reservoir, and re-rout to a catch can. unhook the level arm from the valve, or jack up to nuetral position, where oil will be returned to reservoir, not pushed to struts. run engine , and add new oil as the old is pushed out. when clean oil comes out return line, shut off, hook all lines up, and bleed.

Thanks, Mo. I finally read my FSM (didn't occur to me I had it). The only place it said to drain it is at the bleeder valve at the controller. I'll give that a try tomorrow after I remove the jack and ramp.

tobybul · #4 04-21-2008, 11:15 PM

Got all the work done.... replaced the accumulators, drained/replaced the hydraulic fluid. Used both gravity and mechanical method of draining. First thru the bleed valve at the controller. Then ran the system and discharged the old return oil to a bucket while filling the reservoir with new oil until the return oild was crystal clear.

What difference in ride!!!! No more bouncing around.

tobybul · #5 04-23-2008, 12:42 PM

I bought some Febi SLS Hydraulic oil for $13 a qt but ended up using Shell Hydraulic oil used for the same purpose that I got from Menards for $9.95/gal.

mobetta · #6 04-23-2008, 01:44 PM

what spec on the shell oil?? some Hyd oil can apparently do moore harm than good- degrade the rubber in the system.

tobybul · #7 04-23-2008, 05:54 PM

Not sure what you mean by spec but it is made for mobile hydraulic systems. It is petroleum oil. Here are the approvals...

Approvals: Eaton/Vickers M-2950-S, I-286-S and Denison HF-0, 1 & 2

http://www.valvoline-technology.com/upload/dynamic/Valvoline%20and%20Eaton%20Premium%20Hydraulic%20Fluid%20PI%20Sheet.pdf

mobetta · #8 04-24-2008, 11:42 AM

its your car. But i would prolly not use it- it just is not worth saving $20 over, IMHO...

the shell aero 4 is supposedly good stuff.

YMMV

heres a few posts on it- some peeps use atf, pS fluid, etc. but I will pay the $9/L or even $17/L local. and I have 2 spare pumps.

http://www.peachparts.com/shopforum/showthread.php?t=175042&highlight=hydraulic+oil+airport&page=2

http://www.peachparts.com/shopforum/showthread.php?t=136210&highlight=hydraulic+oil+airport

JimmyL · #9 04-24-2008, 11:52 AM

Good job Toby. Isn't a properly operating SLS a joy to drive! Just try to bottom out that back end. I am constantly amazed at what it will absorb, and do it smoothly.
At a 3-4 dollar a bottle difference I'm not sure I would have chanced other fluid, but it isn't like the MB/Febi fluid can be that much different than other hydraulic fluids. I'm just playing it safe......
Seems like somebody on here used tractor hydraulic fluid and it worked fine, until seals started leaking.

tobybul · #10 04-24-2008, 05:09 PM

Actually, I really was not trying to save money although in a way that is the side effect. After all, I have 4 bottles of the Febi.

At the store, I was reading the features of the Shell Fluid that it is made for hydraulic mobile sytems and was impressed by the claim. In addition, the fluid I drained out of the SLS looked pretty dark and wondered why so. I therefore wanted to try something else that I felt has been tested and compatible for the same application.

tobybul · #11 04-25-2008, 10:41 PM

Ok, Ok, since y'all put the fear in me... I took out the Shell oil and replaced it with the Febi Hydroneumatic oil. I guess in a way I didn't want to risk it either.

mobetta · #12 04-25-2008, 11:04 PM

well shoot- I was hoping you'd be the guinea pig. ohh well- better safe than sorry, and its not like you need to change it every 3k or anything.

sure is a nice driving car now, ain't it??

I did a front end rebuild+ swapped accumulators= sweet. now I know what it feels like to drive a benz. of course the wife asked why didnt I fix the bounce when she was pregnant.

tobybul · #13 05-02-2008, 07:19 PM

Well, maybe it was good that I took out the Shell Hydraulic oil. Here's Shell's response:

Unfortunately, the MSDS that you forwarded on the Febi Oil does not give any specifications to compare against the industrial hydraulic oil Shell Tellus Oil 32. Shell Tellus Oils were not made to meet any automotive applications and should not be used as a MB leveling fluid. The Product Data Sheet for the Shell Tellus is attached.

only thing I don't get is the data sheet says its also for mobile hydraulic fluid power transmission systems. Oh well, maybe they are playing it safe.

Can't attach pdf. too big. so here is excerpt.

Product Description
Shell Tellus Oils are premium performance mineral based hydraulic fluids formulated with patented Shell additive technology in combination with high quality base oils to meet the requirements of a wide range of industrial and mobile hydraulic applications.
Shell Tellus Oils provide numerous performance features and benefits which allow end users to maximize their hydraulic systems’ reliability and efficiency. Shell Tellus Oils are formulated to provide excellent thermal stability which results in less chance for sludge formation, which can cause clogging of servo valves and actuators. Unique product chemistry provides antiwear to help protect piston, vane and gear pumps through a wide range of operating conditions. Shell Tellus Oils are formulated to undergo ultra-fine filtration which is essential in today’s hydraulic systems. Careful use of additives provides quick air release properties to help minimize pump cavitation. Good water separation properties help prevent the formation of water-in-oil emulsions and prevents consequent hydraulic system and pump damage.
Applications
• industrial hydraulic systems
• mobile hydraulic fluid power transmission systems
• circulating oil systems
• general machine lubrication
Features/Benefits
• good thermal stability
• excellent antiwear
• resistant to oxidation
• excellent filterability
• good water separation
• excellent air release
Approvals
• Denison HF-0, HF-1, HF-2
• Eaton/Vickers M-2950-S (Mobile) and I-286-S (Industrial)
• Cincinnati Lamb P-68 (ISO 32), P-70 (ISO 46) and P-69 (ISO 68)
• Komatsu Engineering Standard (ISO 46)