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Fixed the problem. This was my last ditch attempt before throwing in the towel and dropping the coin for a new pump. I reused my old gasket 00-80, but also purchased the newest thin gasket 271-238-03-80. Before putting it all back together, I blobbed a thick ring of that Permatex Black gasket maker both inside the groove (where the 00-80 goes), as well as on top of the 00-80 gasket after I squished it back into the groove, and before installing the thin gasket. In addition, I also used my finger and smeared gasket maker all over where the large O-ring goes. It looks awful, but it looks like the leak has been completely stopped. I didn't put any gasket maker between the thin gasket and the engine block.
So far it has been a few weeks and everything seems to be holding.
I just wanted to thank all of you for the helpful feedback. I knocked out my Vacuum Pump today, largely due to this thread and the wealth of knowledge most of the members of this forum provide! I ended up biting the bullet and replacing the pump entirely. From what I've seen, it's a hit or miss for most to successfully rebuild the pump, and for it being 10 years old, I thought of it as a justifiable purchase. Ps. Again, here's the best price I've seen for a brand new OEM Pierburg Pump: https://www.eeuroparts.com/Parts/674...ump-724807070/Use Coupon Code 3OFF149 for and additional 3% off!
It took me about an hour and twenty minutes - largely due to me dropping the damn bolt when installing the new v-pump (Had to jack the car up and unbolt the splash shield to find it). I also found it unnecessary to loosen the engine hook - I managed to fit a small ratchet/socket in there to loosen the two pump bolts. The cars braking system seems much smoother now and there is no more oil coming from the back of the engine.
Next step is to clean all of the oil from the previous pump...
In addition to this project, I also tightened up the parking brake from the pulley system underneath the rear seats (once again, thanks to this forum). I wiped it down and added some WD-40 Silicone spray to keep it smooth and lubricated. Good as new. No more annoying rattling noise when going over bumps and I only need to push the brake 60% of the way down now.
PS - Big shout out to @RWDlifer for all of his help as well, the dude is a HUGE resource on here.
Last edited by Norsk_Johnson; 03-17-2015 at 02:32 PM.
Hi, i found your replacing the vacuum pump for mercedes c230 very helpful.
only one problem, what kind of tools do i need? i tried the ones you said on link but did not work , seems to be a different kind of socket. locks kind of a star shape. where can i buy these tools?
i really appreciate your help, need to replace it a.s.a.p.
Hector
Hi. Sorry to bring up an old thread. I followed all instrucstions below incl parts but had a little issue on the proline o ring. Did your pump sit flushed on the proline o ring? Mine seems to have a little of a gap. See pics
Originally Posted by nc1wynot
I received so much assistance on here in regards to maintenance on my MB so I felt it only right to share. This seems to be a pretty consistent problem with C230 Kompressors. I got wind of it from my dealer when they were installing the "wire harness" campaign. They said there was an oil leak on the back wall of the engine and it was the vacuum pump. They wanted $480 to replace it...
So, I felt this DIY tutorial would help out...
Vacuum Pump replacement
SEAL RING 6689970145 Gasket 2712380180 Pump 2712301165 (new pump comes with seals) Pro-Line PPL-35610 oil filter for gasket ¼ inch ratchet 8mm socket or 5/16 12 wall socket Torx socket set (if replacing seals) About 45 minutes
There seems to be two options with this. Either replace entire pump (easiest, $140+-) OR take old one out and replace seals (less pricey 12+-, but cause for leak may not be seals)
Option #1 1.Better to do this repair when engine is cool. 2.Gather tools. 3.Locate pump on back engine, passenger side of engine, between fire wall and engine. Remove engine cover. Remove 2 hoses in image by squeezing and pulling up. Makes it easier to see and get to. (may need a light and mirror) 4.Loosen 8mm bolt on engine hook from driver side (easier to reach from driver’s side). There are 2 but you should only need to loosen the top one. 5.Put flat tip screwdriver in hole of engine hook and slide it towards the driver side. It may take a bit of muscle but its easier then taking the bottom 8mm bolt out and removing the engine hook. You only need it out of the way to get to the 8mm bolt on the pump. #1 bolt in the image. Be careful not to drop the bolt. 6.Then go around to passenger side. Loosen and remove 8mm bolt on passenger side. Make sure you have a hold of pump while getting to the last few threads of bolt. (You don’t want the pump to fall) These bolts should be pretty easy to remove once you loosen them with a rachet. 7.Look at the pump removed, the position of the gear. That’s the way you put the new one in. It will only go in one way. 8.Install new vacuum pump, tighten engine hook bolt, and replace hoses. Start car and inspect for leaks.
Option #2 1.Everything the same except you can replace gaskets. Once you have it out, you will see the first two. One is a ring gasket on the shaft and the other is a flat gasket on the mount. 2.There are 5-6 torx screws on the pump body. Unscrew and open. There is a gasket underneath that is the same size as the one that comes with the Pro-Line PPL-35610 oil filter. It’s a little tight but it can be stretched into place. 3.Put the torx screws back on and put back together, same as above.
Great DIY, but I have one quick question. Since this is the brake booster vacuum pump, did you need to drain the brake line, refill brake oil then bleed them out of air , or that wasn't needed?
Thanks
Great DIY, but I have one quick question. Since this is the brake booster vacuum pump, did you need to drain the brake line, refill brake oil then bleed them out of air , or that wasn't needed?
Thanks
It's the brake vacuum pump...creates vacuum for the booster. No brake fluid in it.
Finally threw in the towel and replaced this stupid pump. The old one kept slightly leaking, and finally I couldn't stand it anymore. The amount of oil leaked seemed to be worse after aggressive driving. Guessing this is because the higher RPMs cause the leak to open up a little bit more.
The latest pump as of the time of writing is 271-230-11-65. Rather funky new look. This came with all gaskets and o-rings required, as well as the gasket 271-238-01-80. I picked up a Pierberg, which should be identical to the MB one, minus the MB logo, which is conveniently scratched off.
Even though people don't recommend this for some reason (maybe it makes any subsequent repairs more difficult), I recommend a thin bead of RTV gasket maker on both sides of the gasket.
The car is definitely slightly smoother during the lowest part of the RPM. I wouldn't call it night and day, but it does purr a little more. Hopefully the oil leak is stopped once and for all.
Anyone know the correct torque rating for those 2 bolts?
Last edited by slammer111; 04-30-2022 at 04:18 AM.
I was losing 1L every 5000-7000km. It was bad. At the rate I was going, the pump would've paid for itself in lost oil over a few years. Not to mention the plastic underbody panel was consistently wet, and a bunch of fish out there probably died as a result.
Mind you, at the time I was also losing oil through the leaky cam sensors at the front, which were repaired last year. So this is why they lost the war.
Interesting, I've also been losing about 1L for 6k km, but the last time I checked there was no oil on the underbody. Although my pump is leaking - confirmed by reaching behind the engine and getting oil on my fingers.
What's funny is I think the dealer had "replaced" the pump in 2011...
This might also be due to oil burning in the engine rather than just the pump leaking.
Incidentally, I also was doing the cost-benefit analysis,
the pump is about $150, while the oil I can get
for $27 per 5 quarts ~ $6 per quart.
So I can be adding oil for 25 times for the price of a new pump
that's +-130k km of driving.
That's something like 10 years for me.
Pop open your hood and shine a flashlight on the plastic underbody panel from above. Mine is completely shiny with what I presume is oil. No rain here in the summer, so it's definitely not water.
So my new pump decided to also leak oil. Slower than the old pump, but still a few drops daily. Got annoyed enough and replaced the V2 gasket. Reused my old V3 one (271-238-03-80) from my previous attempt, but not before adding a nice bead of gasket maker between the pump and gasket. Sure one isn't supposed to add any here, but if MB actually built a decent gasket, I would've have to. Anyways, it worked. Looks like the leaks are finally gone for good.
I mean when I took off the plastic underpanel it was completely dry.
So there is a rubber gasket and a metal one that goes on top of it?
Would it make sense to apply some rtv on both sides of the metal gasket? That way all the potential leaks should be subdued..
I mean when I took off the plastic underpanel it was completely dry.
So there is a rubber gasket and a metal one that goes on top of it?
Would it make sense to apply some rtv on both sides of the metal gasket? That way all the potential leaks should be subdued..
There is a metal gasket with a rubber coating on both sides that goes between the pump and motor. The rubber layers are supposed to seal between the pump and gasket, and between the gasket and motor. Unfortunately for me, I still had a leak somewhere. I took a gamble and only added gasket maker between the pump and gasket, and it worked. There is definitely the possibility that there may be a leak between the gasket and motor, but for me it wasn't the case. I thought I read somewhere that MB does not recommend any sealant products being used on the engine block. Probably has to do with potentially damaging the mating surfaces if the stuff needs to be removed in the future.
Thanks for the clarification!
Btw, how did you make sure that it was leaking between the pump and gasket, and not between the engine and gasket? Is it evident on the gasket or..?
Thanks for the clarification!
Btw, how did you make sure that it was leaking between the pump and gasket, and not between the engine and gasket? Is it evident on the gasket or..?
I actually had no idea where the leak was exactly - all I knew was that after driving, there would be a drop or two of oil on the transmission bell housing, directly beneath the pump. I was honestly ripping my hair out over this issue, as this leak was still happening with a brand new $140 pump and V2 gasket (which comes with the V2 pump).
Since I wanted to avoid getting any gasket maker on the engine unless absolutely necessary, I removed the V2 gasket and added my (previously used) V3 gasket, then added gasket maker in the interface between the pump and the gasket first. It was a total gamble, and in this case it worked.
The gasket maker might actually be unnecessary with the V3 gasket as the sealing contact area is larger on the V3 gasket, but I wasn't taking any chances.
It's been a week of hard driving, and the bell housing is completely dry. Finally.
Last edited by slammer111; 07-03-2016 at 08:35 PM.
Time to bump this thread. A small leak has appeared yet again.
I'm almost out of ideas. Already replaced the pump. Going to try replacing the gasket (between pump and motor) for the 3rd time, along with adding more gasket maker.
Definitely losing oil again, about 1L every 5000 km.
My only guess at this point is that the 2 bolts aren't being torqued correctly. Does anyone know the correct torque rating for those bolts?
Last edited by slammer111; 09-11-2016 at 06:44 AM.
it's 8nm, but good luck getting a torque wrench back there....I did this DIY over a year ago and I'm still dry. I went to the parts store and just tried every o ring I could lay my hands on, and added a generous amount of gasket maker.
The gasket between the halves is more likely to leak vs the gasket between the pump and the head.
Thanks for the reply. Wondering if my leak is actually caused by overtorquing the bolts. I'm sure I was over 8Nm before.
The pump is new (just a few months old), so that's not the problem. The problem is the gasket not mating properly with the pump and motor surfaces for some reason.
Anyways, I added a nice bead of gasket maker on both sides of this thing. Let's see how well it holds up.
Are you sure about that? Why would you need a pump chamber full of oil to create vacuum? vacuum pumps would typically pump only air no?
So after thinking about how this pump works while my car was apart yet again, the answer is YES.
So there are 2 channels for the pump. The purpose of the pump is to draw a vacuum, but it also requires lubrication. This is where the engine oil comes in. Anyone who removes the pump will find that the cam drive is absolutely covered in oil. A bit of this constantly flows into the pump and provides the lubrication required for those sliding parts inside. To prevent the pump from flooding, that's what the triangular hole with the small angled plate is for. If the pump is removed and the cam drive part is spun, oil shoots out through this hole. This is the excess oil removal mechanism. While the oil is flung to the outside and out of the pump, the tiny little air hole in the middle of the spinning mechanism takes in air from the inside of the pump, and directs it into the engine.
A bit of an unusual way of creating an oil-free vacuum, but it works.
With that said, if my theory is true, this also means that it was completely unnecessary to replace the pump with a new one, and that I should've just repaired the leaking large main seal with some RTV and called it a day. Oh well, can't hurt with a brand new pump.
Correct. It's a vane pump, one chamber has oil while the other chamber draws vacuum. Simple and effective and runs off the engine rather than having it's own power source. Some small piston-powered aircraft engines use them too.
Looks like my engine is STILL slightly leaking oil, even though I applied gasket maker to both sides of that gasket. Cleaned up the engine and oil drips, tightened the bolts a little more, went for a test drive, and found a few drops of oil again, directly below the pump on the transmission housing.
Anyone else have any ideas? I cannot get this part to stop leaking for the life of me. Not sure if yet another brand new $20 gasket is going to fix this.
Do you find oil on the underside of the pump though? I have literally drops of oil on my fingers when I run them along the bottom edge, and could not really see any traces on the tranny housing.
Other than that, might be that the bolts go through the engine walls and oil is seeping via the threads - I heard threadlocker helps in this case.
Do you find oil on the underside of the pump though? I have literally drops of oil on my fingers when I run them along the bottom edge, and could not really see any traces on the tranny housing.
Other than that, might be that the bolts go through the engine walls and oil is seeping via the threads - I heard threadlocker helps in this case.
No oil at all underneath the pump, interestingly enough. An inspection tool (illuminated mirror) confirmed this. Ran my fingers underneath the pump too, as well as between pump and engine. Completely dry.
How practical is it to fashion something just above where you have the oil stains on the bell housing to see if it's dripping from above or leaking from inside the housing?
03-13-2015, 07:22 AM
replace vacuum pump
Anyways, it worked. Looks like the leaks are finally gone for good.
