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ABC Pump removal guide

40K views 14 replies 10 participants last post by  GreenZZZ  
#1 ·
Hey. I have decided to do a write up regarding the removal of the ABC suspension pump on the CL models. I have done this because there is very little in the way of information of how to remove the actual pump. What very little is out there seems to be misinformation and regurgitated eighth hand rumor.
One such snippet of misinformation is that the pump is held onto the block using only 3 bolts. However there are 4 of them.. This 3 bolt theory from what i have read seems to be the general consensus. There are four gentlemen
Please use this thread as a guide and use it an anyway you like and undertake your task in any order you choose. This is just the facts of what i have done first hand. The only so called special tools are a set of Star shaped sockets.
The whole job took me about one hour 15 mins.

The reason for the pump removal is to rebuild my pump with a new seal set i have. This is due to my pump spewing out oil at a very alarming rate. However as you will see at the end of the thread, the cause of the leak is much more easier to rectify than first thought.
1\ Loosen the front 3 star bolts from the front of ABC pump pulley before belt removal. [pic1]

2\ Remove the serpent belt from the pulleys. Make a note of there orientation.

3\ Remove belt tensioner by removing just two star bolts.

4/ Unclip the electrical connection. also for better access i chose to remove the little earth strap and removed the hose holding bracket.[pic2&5].

5\Remove banjo bolt 1&2 [pic 3&4]

6\The first rear bolt to remove is a star bolt which connects the bump to the engine block via a bracket. pic 6 shows the position on the rear star bolt via a socket i put on to show you. Pic 7 shows the socket on the ratchet. Pic 8 shows the bracket and pic 9 shows were the bracket attaches to the engine block under the cylinder heads.

7/ Now for this little bugger, its the 13mm standard nut also at the rear of the pump. Its very hard to see and i have tried to show you the location via pictures 10&11 and the location hole in pic 12. It can be easily got to from the top through the slot with a long 13mm spanner.

8/ Remove the two front star bolts. There locations ore shown in pic's 13.

9/ Remove the pump pic15....easy :cool:

10/ In picture 16 i have mocked all the attaching bolts and nut, along with the orientation of the support bracket.

11/ NOW THERES THE REASON FOR MY PUMP SPEWING OIL in pic 17
A split reservoir.

Now you know:thumbsup:
 

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#4 ·
First of, yes the intake tube is just pulled out. There are no clips, it just pulls out. And yes compared to the mid engine Ferraris i am used to working on, yes there is so much room. However the rear single 13mm nut on the ABC pump is a bloody awkward bugger to get at.
Price wise anything between 1-2K plus fitting:big laugh: How i laughed, so i simply bought a seal kit and rebuilt it my self.
Ignore the BS about the pump can only be primed and bleed using the Mercedes dealer computer at the dealers. And that you will burn the pump out bla bla bla. Its a pump!!! How can the computer feed the pump with oil without the pump turning???? Wake up guys :D This is as true as the information telling us that there are 3 bolts holding in the ABC pump:bs: But i understand that Mercedes want owners to pay the usual Mercedes tax :)
Its simply bleed by keeping the rear banjo feed bolts on the side of the pump loose after fitting the pump back into the engine bay. Without the serpent belt fitted, turn the ABC pump pulley by hand. At the same time blowing into the ABC oil tank to add a little pressure. Then as you are turning the pump, the oil is forced via the pump turning and the little pressure, through the pump and out of the feed banjos. This means the oil has now filled the pump and you are ready to go once the two banjo bolts are tightened. Once the engine has been started and the ABC UP/Down button cycled maybe 10 times times to bleed the remainder of the air, the systems bleed.
 
#5 ·
Awsome writeup !!

I agree, at first when you read posts about the ABC system it is made up to be some kind of very complicated system that is almost impossible to work om DIY, it turns out, that most of the jobs can be done easily and at fair prices, if you know what to look for.

Could you be so kind as to link to where you bought a rebuild kit for the pump?

Thank you

David
 
#7 ·
#8 ·
well taken mine off after suspension keeps dropping unless I rev the engine above 2000 rpm...
anyway removed it with the help of this post and now wondering how i can take it apart to refurbish the seals....Would also be interested in that spare set of seals if you still have them...
thank you for this fab post...
 
#9 · (Edited)
Hi, i was going to write a how to strip the ABC pump. However there is already a how to write up out there, and i was reminded on another forum that it was already done. So i never botherd. The only thing that i was going to do diferent was use better detailed pictures. But anyway....
You can easly find the write up if you look.
I am in the UK and if anyone wants the spare kit i have ( i am not giving it away, you can have it for what i paid for it from the USA) , just pm me. Simple.
 
#11 · (Edited)
I'll add some notes to this as I just fininshed a swap of the ABC pump. Decided to get a new LUK pump since FCP Euro has a lifetime warranty. Hopefully that will keep me going next time it fails.

Great pointer on the bike pump. Worked great!

The bracket bolt under the exhaust is an E12 torx. I spent 30 minutes trying to put an E10 on it which was just stupid of me. Its hard to see. If you are researching tools, get an extra long 13mm box end wrench for the fourth nut @Ferrarispider calls "the bugger". Have some 16mm copper crush washers for the power streering banjo connectors. The ABC banjo's use O-Rings. Two if you remove the ABC pressure line at the front of the pump, 4 if you remove the banjo connector at the back (as shown above) as you'll need to bench install the cylinder on the side of the pump which has a 2nd bango connector.

I was able to lift the reservoirs, sneak a kitchen trash bag under them, poke a hole in it above a pan and then open the system up containing the mess. The MB docs show clamping the hoses which should work pretty well. I spent about 8 hours as I cleaned everything up and work at a snails pace. I was able to enjoy the silky smooth ride for 2 days until the instrument cluster blew up. :banghead:
 
#14 ·
6\The first rear bolt to remove is a star bolt which connects the bump to the engine block via a bracket. Pic 8 shows the bracket and pic 9 shows were the bracket attaches to the engine block under the cylinder heads.
Your post inspired me to undertake the replacement of my ABC pump.
However - the far end of the bracket is utterly inaccessible to me. Your photo shows an area a cat could walk through - where as I can't even touch the end of the bracket (let alone fit a socket to it:).

Any tips from anyone? Something must be removed? Stumped!

Edit: finally paid the kid next door (tiny hands) to remove the bolt! Ugh.
 

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