vacuum pump rebuild question - PeachParts Mercedes-Benz Forum

ichbineinekrous · #1 12-04-2008, 04:34 PM

ok I know this sounds lazy, but it isn't.. I don't understand which rebuild kit I need for my 83 240D, I'm assuming its a torn diaphragm because they aren't any noises or vibrations and a constant low ~15" hg that takes awhile to build. I need to drive the car while I'm waiting for ********Az to send the right kit, and don't have a stubby enough screwdriver to get the cover plate off of the vacuum pump. There is an emblem of some kind on the pump but it isn't recognizable. I don't understand why there are so many different kits, can anyone get me pointed in the right direction??

Thanks

Here is the page that shows the various options

https://www.***************/search/product.aspx?sid=1b5q0345fxenxl55rdrf5m55&makeid=800016@Mercedes&modelid=1193004@240D%20&year=1983&cid=18@Electrical%20%26%20Vacuum&gid=5025@Vacuum%20Pump%20Repair%20Kit

Oracle12345 · #2 12-04-2008, 04:39 PM

you are gonna have to look up what kind of vacuum pump you have and order the right kits.

ichbineinekrous · #3 12-04-2008, 05:50 PM

Do you know where on the pump the part # is imprinted, I've looked from every angle including underneath and cannot find it.

Stevo · #4 12-04-2008, 05:51 PM

You have the "later" pump, so the kit is #1, the more expensive one

ichbineinekrous · #5 12-04-2008, 05:52 PM

I guess I'll just have to go buy a super stubby flathead screwdriver tomorrow and remove the cover plate and try to match the diaphragm shapes to the ones in the replacement kit.

Jim W. · #6 12-04-2008, 05:56 PM

Call the M-B Classic Center with your VIN number, they will look it up for you and direct you to the correct kit.

Jim W.

ichbineinekrous · #7 12-04-2008, 06:17 PM

Quote:

Originally Posted by Stevo

You have the "later" pump, so the kit is #1, the more expensive one

So I don't have diaphragms at all?? That was the one thing from my readings that I was pretty sure of, I thought that the later 240's had the same pump as the 300 turbo's. This would be easier if I had my other car here right now. doh.

Stevo · #8 12-04-2008, 07:40 PM

Quote:

Originally Posted by ichbineinekrous

So I don't have diaphragms at all?? That was the one thing from my readings that I was pretty sure of, I thought that the later 240's had the same pump as the 300 turbo's. This would be easier if I had my other car here right now. doh.

My later (+80) 240Ds have the "newer" style w/o the diaphram and my 80 has the older diahpram pump, the less expansive to rebuild. You dont have a vacuum line to the top of your air cleaner, right?

ichbineinekrous · #9 12-04-2008, 07:45 PM

No just the one metal line to the brake booster. So I need the piston style kit correct? Thank you for the prompt help, ordering parts now.

Jon J · #10 12-04-2008, 08:48 PM

Hi I just rebuilt my pump on my 81 240D you need the kit without the diaphram. also you will need to order the base gasket that is not with the kit. Some recomend that you also replace the bearings in the pump also. they are 6mm x 6mm x19mm and only cost about five dollars each. (get the ones without seals). I had low vaccume and leaks in the old pump that turned out to be the check valves. I used the camera on my cell phone to record the disassembly just in case of a memory failure. after I was done the pump pulled 22 in. vaccume and held indefinatly. this was with all lines pluged except the brake booster. I chased down leaks the next day and found a bad drivers door switch and a bad fuel door lock. now the car holds vaccume all night long and then some! If you have any questions give a holler.
Jon J
81 240D
300,000 +

ichbineinekrous · #11 12-04-2008, 09:00 PM

Quote:

Originally Posted by Jon J

Hi I just rebuilt my pump on my 81 240D you need the kit without the diaphram. also you will need to order the base gasket that is not with the kit. Some recomend that you also replace the bearings in the pump also. they are 6mm x 6mm x19mm and only cost about five dollars each. (get the ones without seals). I had low vaccume and leaks in the old pump that turned out to be the check valves. I used the camera on my cell phone to record the disassembly just in case of a memory failure. after I was done the pump pulled 22 in. vaccume and held indefinatly. this was with all lines pluged except the brake booster. I chased down leaks the next day and found a bad drivers door switch and a bad fuel door lock. now the car holds vaccume all night long and then some! If you have any questions give a holler.
Jon J
81 240D
300,000 +

this is why I love this forum. Thanks Jon, I'll PM you if I run into a snag.

ichbineinekrous · #12 12-19-2008, 12:06 PM

I'm having a problem with my rebuild of the vac. pump. I've got it rebuilt and reinstalled and now I'm getting zero vacuum according to the mity-vac. Did I miss something obvious? The only thing I wasn't able to disassemble was the 22mm port on top of the pump, I'm not sure if there's a check valve or something in there. Any suggestions are greatly appreciated. Thanks.

tangofox007 · #13 12-19-2008, 12:12 PM

Some of the o/h kits supply check valve seals that are too thin.

Also, you really need to inspect the check valve that is in the nipple where the hard line attaches to the pump. They have a habit of coming apart and blocking air flow into the pump.

ichbineinekrous · #14 12-19-2008, 12:28 PM

thanks tangofox, that was my next thing to check, do you know if the check valve inside there is similar to the ones that came with the kit, or is it a special one?

ichbineinekrous · #15 12-19-2008, 01:17 PM

I think I just answered my own question, I removed the check valve and when I apply a slight amount of suction from the downstream (upper) side of the check valve it leaks slightly. I just checked ******** AZ and they want $53 for the part!!!! I am dead broke right now and need the part so I can sell the car, for a quite reasonable sum, but I can hardly ask 1700 if the car doesn't shut off. Does anyone out there in mercedes-land have a spare, or used check valve they'd be willing to sell me for less than $50?