LGAFF

I see some people refer to priming an ABC pump; typically with air pressure...can any describe how much pressure...do you just use small bumps of air, etc

kbob999

I have not done this, so don't use this as a guide. This is what was explained to me when my system locked down.

What I've heard is just a small bump of air in order to force fluid into the pump past the pump 'inlet valve', rather than relying on gravity. If I had to guess, I would limit it to 5 PSI.

If the ABC system does not see pressure within 3-5 seconds, or some short time, it locks down the system, including the inlet valve. You then have to shut it all off, and use the prime again to force fluid into the pump.

Eventually, the system pressure is recorded, and the inlet stays open, and operation is normal.

I'd like to also know the details, so we can both learn what the right way is to do this.

gafitanu

I ran into this when I had to change my pump. I didn't read the WIS all the way so I started the car and I quickly got an ABC error. Also raising/lowering wasn't working and from what I could tell the fluid from the reservoir was not going into the system. Kbob explains it beautifully.
I took the air blower and fitted to a short piece of rubber hose so it would seal against reservoir neck. I didn't know how to control the pressure so I increased it until I heard like a gulp. I added some fluid as required, raised and lowered for 10 times, rodeo twice, corrected fluid level. Almost 3 years ago.

knowbenz

Do this weekly, activate rodeo on SDS, apply shop air to reservoir, stubborn ones sometimes need a little extra rpm

LGAFF

So are you saying it can take weeks to bleed a system? Mercedes told me I was wasting my time, had to be the pump at this point

knowbenz

No, you asked about the process. Never takes more than a minute or so. Some take more pressure than others, some need increase RPM and some don't.

Did you attempt to prime it with air pressure? How many Bar could you achieve?

Did you call the dealer to ask advise on how to prime it or how did it come about that they told you you're wasting time?

LGAFF

Every cars has it quirks, I don't know them for Mercedes like I do for LT-5 corvette engines.... I know a Mercedes Tech, asked him if they do it....they do....I bumped mine with air and then drove the car for 40 minutes with no ABC code...that's never happened since the prior pump went bad. However, there are some that say on a bad pump priming it will make it work properly for a short time

The next morning....ABC code was back on within a few minutes(10) of startup.

It seems to me there isn't a lot of solid knowledge on ABC, a lot of opinions on the cars; some ideas work for people.....but a lot of unknowns

When we checked the codes today the max was 171 bar achieved by moving RPM up to 2K

moretech

I have seen some members of the forum mention priming via hand turning the pump after taking the fan belt off. Can this do the priming ok as an alternative? It seems almost easier on paper at least. But I wonder if it is real hard to hand turn the pump.

moretech

knowbenz

ah OK now that sounds like a pump. The pressure was much lower at idle?

LGAFF

124 idle 171 with alittle rev

I think I can beat my last time in changing it....lol

latemodel21

I realize that priming the pump has been covered more than a bit in this thread, but in the interest of clarity I thought I would add a little bit including the specific info from the WIS.


I recently had a leak at the pump output (broken bracket that secures the inline damper to the tandem pump on a 2003 sl55 caused the damper to break at the banjo fitting).

After reassembling the system , I needed to prime the pump. I had trouble getting the correct pressure in the tank to prime it (bad timing, insufficient pressure? ... not sure). So ... went to the WIS and followed the instructions for pressurizing the tank to 1 bar (15psi) AND THEN starting the motor. worked like a champ, and I was able to one-man it.

Attached are the WIS instructions (step 5 and 6 cover it) and a pic of the RIG I put together so I could pump it up (with my cooling system pressure tester).

Grateful for everyone who participates here and help make owning a fine car affordable.

Cheers,
Chris

qnbenz

Do you have the rest of the instructions? Thanks!

latemodel21

I am not sure I understand your question. I attached the complete set of instructions. Are you looking for the instructions for a related task?

Chris

qnbenz

Oh, I didn't realize step 6 is the last step. Sorry about that. Thank you for the info.

latemodel21

you are welcome.

Cheers,
Chris

qnbenz

I have a Ryobi tire pump like the one the video below. I think with a simple adapter it should work. 1 bar ~= 14.5 PSI. Has anyone tried this?

knowbenz

If you can regulate the pressure it may work. Ive seen several tanks blow up with too much pressure

qnbenz

I'll stop at 14 PSI just to be safe. Thanks!

J.Becker

ItalianJoe1

Never tried it with a small compressor but the instructions say to use a radiator pressure tester, so it doesn't expect a ton of volume. It happens quick, as long as you can build a little pressure in the bottle it will get the pump going. I stick a blower nozzle with a rag into the dipstick opening and give it a quick shot, usually works right away.

beanieBenz

Thanks for this picture of the "RIG" you put together. I'm going to do this job tomorrow. I noticed in your image of the WIS software the picture is so clear. I have WIS running off Virtual Machine software and the pictures are not nearly as sharp as yours. Is there some way to adjust the display to sharpen the images? Thanks in advance.

latemodel21

those were pulled directly off the mercedes on-line resource (back when I had access to a subscription on "STAR Techinfo" ). Just for grins, if I get a chance, I will see how those images compare to the same pages on my Star testers (one with a VM setup and a couple that have an internal drive) and will share if I notice some differences.

Cheers,
Chris

ChrisVannoy

Can you elaborate on how you put this pump tool together please? I’m hoping to be able to
work on my system this Sunday!! Thank you In advance hope you have a great day