ABC System Hydraulic Fluid-2004 SL500
 

I just traded in my 96 SL500 for an 04 SL500 with 26,000 miles. Three questions. The book does not label all of the engine compartment.

1. There is a black filler cap with a small dip stick on it just in front of the shock on the drivers side. Is that the ABC filler? If so, it is showing right at the bottom of the little dip stick.

2. The book says that you need to use Mercedes Hydraulic fluid. Is this the same Mercedes fluid that I used to refill my convertible top hydraulic reservoir in the trunk on the 96? That was official Mercedes Hydraulic fluid.

3. I have almost a full quart of Mercedes Hydraulic fluid-ZH-M and want to make sure that I use the right fluid. Is this the correct fluid?

Thanks

No ABC fluid is different. Comes in a blue metal can.

Yes it is a duel power steering/ABC pump reservoir. ABC fluid is the one with the ~six inch dipstick and needs to be checked while running.

ABC system
 

Just a suggestion about your ABC system in mid 2000 SL500's. The two marks on the dipstick are for running and when car is off. The top one is for at rest and bottom is for while running. Pretty obvious. But you might run into an issue if you refill or top off while car is running (tank will be much lower). First, it takes maybe 30 minutes for the fluid to flow back into the reservoir after shutting off the car. I noticed that if you fill it WHILE running, there is a VERY good chance you will end up with fluid overfill, running down the tank and onto the floor. When I did a flush and rodeo I saw that the fluid level while running was lower than expected. If you fill to the "while running" mark when you shut the car off, the excess fluid flows back into the tank and overflows. Make sure that you wait 30 minutes AFTER you turn the car off and check the level. AS long as it is just below the top of the reservoir tank you will be ok while running. It is a closed system so there is no where else for the fluid to go.

SL500 ABC LEVEL
 

My 2005 SL500 drops at the NSF quite quickly on occasion once the engine is off.
Other times it seems to stay at the correct level.
The oil level is on the bottom of the dipstick when the engine is cold .
I have topped up , is this OK ?

I do believe that if you overfill a little, there is enough room in the expansion take to accommodate it. However, if there is too much (and if I remember correctly), the fluid will overflow the container and spill out. It's not like overfilling the engine oil which would cause harm to the engine. However, I would rather the reservoir to be a little over than under. Insufficient fluid in the ABC system can be devastating.

It's a sealed system until it's not. These older cars tend to develop leaks, especially with the valve blocks and valves. Look for wet spots under the car on the left (driver's side US) ahead of the front and/or rear wheels.

Sometimes the struts also develop leaks. Check for wetness on the struts.

Thanks for the info .
I haven't seen any damp spots on the floor at all .
The only slightly misty area was around the ABC reservoir itself .
As mentioned , the front drivers side (UK) slowly settles within minutes ,but pumps itself up when Neutral or drive are selected .
On other occasions it doesn't seem to go down at all .
I do get the red warning CAR TOO LOW DO NOT DRIVE uopn starting the car .
This extinguishes once drive is selected and the car raises .

OK, you may need to rebuild the valves in the valve block(s). Here's a link to the rebuild kit: https://www.ebay.com/itm/20358581017...mis&media=COPY

Something as small as a piece of lint can get into the valves and create an ever-so-small leak in the seals. Because of the pressure, fluid leaks past the seal and allows that particular corner to drop. However, this usually takes several hours, if not overnight. The immediate build of pressure when you start the car lifts that corner or corners back to normal height. Annoying, but not devastating. There are youtube videos on how to replace the seals. The newer valve blocks are NOT maintainable/repairable. You just need to replace the entire assembly. Again, search youtube for how-tos.

NOTE: You can get the repair kits on Amazon, as well, but at 50% more.

If the ABC res is over filled , where does the excess escape from ?

I suspect the cap will come off. It's not screwed on.

Mine is screwed on

The rubber cap with the attached dipstick is pushed on. The ABC reservoir is in the red outline and the cap is identified by the yellow arrow.

https://cimg9.ibsrv.net/gimg/www.mbw...9a8d183cf4.png