mickey13

I've had a code for ABS Pump out for awhile. I went to the yard and they had a part they claimed was interchangeable from 99 e320, however it did not look the same.

First thing I noticed was that both the part number and the module (number on the black part) were different. While the part did look somewhat similar even with a different part number, I am not sure if these black modules are flashed to the ECU or not.

Second difference was that one of the hoses on the side did not have the additional block that the C43 has. Here are the pictures to illustrate what I am noticing.

So if the module is programmed to the ECU, i can always swap the old module on I guess hoping my ABS problem is the actual pump and not the module. Does anyone know?

mickey13

The pump they have available looks like this where the lines go directly into the main unit without that additional block.


I have found some units on ebay with matching part numbers so I can always pick one up like that, but I was hoping to have this resolved today.

Any ideas?

mickey13

What I'm noticing is that the ABS pump with the additional block (the additional block also has an electrical connection) is stamped at ESP, where the ABS pump without the additional block is stamped ASR.

Aside from the additional block with electrical connection and the stamping, both units look identical. I have even confirmed that the actual pump (motor) is the same Bosch Part No., which is 0 130 108 068. And I suspect that I might just be able to switch motors without changing the rest of the housing.

Does anyone have any idea if I pull the ABS pump (or entire unit), will I need to bleed the brakes and (I'm guessing yes) and also would I get a lot of spillage?

DRBC43AMG

Sure will need a full brake fluid bleed. Strongly recommend using a good quality pressure bleeder. Simple and perfect one man job.
https://www.motiveproducts.com/
Don't know if you need to do some electronic module reset. When I changed a brake pipe connecting to the ABS unit, it only needed a complete bleed.

mickey13

So here is what I have done so far, I did pick up an ABS pump from a local salvage yard. They claim interchangeability but I have my reservations as it is possible for the inside of the pump/module to have differences since the part numbers do not match and one os stamped ASR while ours is stamped ESP. I am certain that the motor on both units is exactly the same. There are a lot of videos on rebuilding these types of motors (the brushes eventually wear down or get stuck), but the motor on this type (our type) isn't quite friendly to servicing. Not meaning it is not serviceable at all, just meaning that it will take some extra effort because it is sealed.

What I have done so far, and I may post some pictures later. Essentially I have disassembled the ASR unit. The 2 screws that go through the motor have screw glue so you have to be careful not to strip those. The motor is connected directly to the module with two wires. I cut those. I opened the module and I can't really tell heads from tails regarding that. I cannot for the life of me open the motor as it is sealed. I could drill through the housing, but I would rather have a test unit to mess around with in the case I end up destroying it (I may do this with the motor I remove from my existing unit after replacement).

Anyway, my next step in this repair is to get into star, check the scn coding for the existing module and make sure that for whatever reason it is coded correctly. (First time using the scn feature). I noticed a decent sized scratch on the motor's housing (on the current one in car), so it is possible that it has already been replaced or damaged in some other way. I also read that sometimes the brushes get sticky and stuck, so they don't need to be replaced just cleaned. PO or mechanic might have given motor a "whack" and got it working in the past.

If scn coding is fine, then I might also give it a "whack" to see if that gets it going (don't worry, I will use rubber hammer lol). If not then, I'll pull the unit, swap the motors (keep existing module), cross my fingers and see if that cures the issue. The car also need a flush, so I will use a pressure bleeder to do the whole system. I don't have a pressure bleeder so I might just build one. I hate to wait for shipping.

And I guess I can answer my own question here using star, but does anyone know if you need to use star to activate the module for a full flush? I was reading the newer models need to activate the pump during the bleed/flush to get the fluid out of the ABS and/or other pumps.

DRBC43AMG

Yeah that's what I also read regarding newer units needing some coding or Star for bleeding.
If you want I can ask a friend in the uk who is a MB and AMG specialist. Just let me know.

mickey13

DRB, I havent had time to fix this pump yet, but looking through MB Star, I do not see any place to bleeding. I will give another look over when the time comes.