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Photo DIY: ABC Fluid Maintenance

173K views 72 replies 34 participants last post by  mrflex  
#1 ·
Granted, this procedure almost unworthy of a Photo DIY! But I think many (such as myself) left most underhood matters to the dealership technicians while the car was under factory warranty coverage. And given the expensive implications (pump damage, etc) if your ABC fluid level isn't maintained, this is probably something everyone should stay on top of.

Sample car is my 2005 CL500, chime in if there are significant differences in other years/models. We are at the right front of the engine compartment (driver's side for left-hand drive cars) as you stand at the bumper looking back toward the engine.

First, the location of the filler/dipstick plugs. (Indicated here by yellow arrows.) There are two and they merely pop off with a squeeze and a pull (they are not threaded). Although the power-steering and ABC systems are interconnected, their reservoirs are separate. The upper, larger one is ABC and the lower, smaller one is for power steering. The larger fittings with the teal-colored labels are the filters.

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Once removed, the dipsticks look like this (this is the p.s. one; the ABC one is longer). There are two markings... ***Edit thanks to our resident expert Eric: "Fluid should never be mid range, at the upper detent with engine off, lower detent with engine on." If mid range with engine on then there is too much fluid. See this note also.

Apparently you can remove them while the engine is running because my mechanic filled them through a clean funnel (highly advised) while the car was idling. And you thought this was a DIY ;)

However note 'official' instructions indicate that engine should be switched off!

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And now, the secret elixir: M-B Hydraulic Oil Q1 32 0001 (Pentosin CHF 11S; Product Code 1408107).

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Upon which it clearly states: Do NOT mix with other fluids. Insofar as a couple of members here have apparently experimented with admixtures of this and power-steering leak stop. I cannot in good conscience recommend such a strategy, particularly since those members were never heard from again! :eek:

This stuff costs about $37.50 per liter at your dealer (cheaper online of course). If your W215 has more than 25,000 miles, though, I'd consider the investment. You may never need it, but if you did, wouldn't you want some handy?

PS: See this post for a less-costly alternative Pentosin source. We still need some confirmation on any possible issues with respect to the alternates though. I expect it's the same thing.
 
#38 ·
I'd also like to know when to check the fluid level ?. I have an SL500 and checked the level today using the following process.

I had driven the car 5 minutes, pulled over onto level ground and with the engine running i pulled the dipstick. I cleaned it off with a clean lint free cloth and re dipped it to check the level. When i pulled it out the level was a clear 1/2" below thw minimum groove mark on the stick.

Was the process i used correct and if so i assume then that the level is too low ?.

I have had 2 ABC Visit workshop messages in the past 6 weeks but only when sub zero temperatures and the car had been stood over night. The suspension appears to work fine and shows no obvious signs of leaks but i ha been advised to check the fluid level.

As usual the MB dealer here in the UK said "the pump is failing" and want ÂŁ1800 to replace the pump.

I cant help think my fluid is too low.

So whats the correct level check procedure please ?.

Thanks

Carl
 
#41 ·
You definitely need more fluid...check as you did and add fluid at least until you get to between the min. and max. marks.

Or go up to the max mark where you may experience some pressure relief after shutting down, but you will certainly be topped up fully.

You should be good after that.
 
#43 ·
Its been suggested over on ther R230 section of this forum tha the fluid should be checked with the car turned off and having been stood for a minimum 5 minutes.

I checked it this way and the level is in between the 2 marks on the stick but if i check with the engine running it drops significantly to 1/2" below the minimum mark.

Is the correct method to check it with the engine running ?.

Thanks

Carl
 
#69 ·
Working on a 2002 CL500 AMG. Not mine

ABCwarning: checked res, too low. Refilled, everything worked.
COLD weather 3 days= massive leak. Found cracked pump housing.

I have rebuilt the ABC pump (o-rings and cover) after the old one clearly failed. I was VERY clean and slow, had the pulley removed with a pulley and put the torch to the pulley until it was SLIGHTLY glowing then DISCO.

The pump was even "primed" and everything fully assembled. Car worked great for a few days and now the front L&R doesn't go up or down more than about 1-2 centimeters. Rear works intermittently as should.
Front was dropped to the ground but, now is stuck at around first height level.

With all the threads on the net I still can't find an explanation on a bleeding procedure.

SERIOUSLY HOW IS THE ABC SYSTEM BLED?!
If cleaning or replacing the valve block is what will solve the issue I still want to know HOW TO BLEED THE SYSTEM?????
 
#71 ·
The ABC system is self-bleeding of sorts. press the level switch up and down allowing time to raise and lower the car while the engine is running.
That will remove all the air. A Rodeo will also remove all the air for sure.
 
#72 ·
When rebuilding ABC blocks here is what I use in case you want to have a go yourself:
For those who don't want to please PM for details and I can help do this work for you.
BUNA 90 O-rings from APG
H90018 .739" ID x .070" C
H90015 .551" ID x .070" C or V90015
H90014 .489" ID x .070" C
H70013 .426" ID x .070" C
H90016 .614" ID x .070" C

This list currently does not include the large O-ring that seals to solenoid to the block as it's doesn't wear.

Some solenoids use what look like PTFE white spacers along with the O-rings while other blocks have spacers made of square cut rubber rings. If yours have these rubber spacers, which sometimes are damaged presumably on original assembly, the parts numbers for these are as follows;
APG #SH70013 , #SH70014 , #SH70015 , #SH70016
The square cut rings can be tricky to install without splitting them. You can hear them split on reassembly.
Quantities are a couple per solenoid.