W115 vacuum pump - ************** repair kit: is this the correct one to order?
 

Hi everyone,

I have a 1974 W115 240D. I've been having vacuum issues (car doesn't shut off!). I want to rebuild the vacuum pump using the kit from **************: https://**************.com/store/early-615-616-617-diesel-vacuum-pump-complete-overhaul-kit

I just wanted to ensure that I'm ordering the right kit to match my specific pump. I'm pretty sure it's the right one (two pipes coming out of it), but here's a couple of photos to double check with folks here who might know better than I :)

https://i.imgur.com/JtI96Mi.jpg

https://i.imgur.com/orGa0uWg.jpg

Is the kit I linked above the right one? Any advice would be greatly appreciated.

Thanks!

Hold off on ordering that kit! Your car does not use vacuum to shut the engine off. There's a cable attached to the "gorilla knob" on the dash, the one you pull to glow and start the car, and push to stop. That cable's other end is attached to a lever on the side of the injection pump (IP). When you push the knob in to stop the engine that lever on the IP shuts off the fuel, or it should.

Look at the LH rear of the IP. You'll see a bracket attached directly to the IP. There's a rubber block there, and an adjustment for the cable end. You'll notice that the cable end has a slot and not simply a hole where it attaches to the lever. It's supposed to be adjusted so that in the run position the lever's pin is somewhere in the middle of the slot, so that when the engine moves around the cable doesn't push and pull on the lever. When you push the knob in to stop the engine the cable should be able to push the lever far enough to stop fuel flow.

I assume that at this point pushing the knob in makes the engine slow down but not quite stop. You might be able to adjust it enough to make it stop. Also, a failure point in this system is that rubber block. I had one that was swollen up from having oil and fuel leaked onto it for years. It was too soft and stretchy and did not allow the cable to push the lever far enough to shut off the engine, and there wasn't enough room to correct via adjustment. I scored a decent replacement part at the u-pull and that solved the problem for me.

Are you having other vacuum related problems? Does your car have the central vaccum powered locking system?

Here's the adjustment procedure from the 615/616/617NA engine service manual:

http://www.peachparts.com/shopforum/...8&d=1552960009

As Greg mentioned, the vacuum pump may not be your issue. But if down the road you do decide to change it, I wrote the following description of my experiences doing this on my 220d.

http://www.peachparts.com/shopforum/diesel-discussion/318203-vacuum-pump-diaphragm-replacement-beginners-perspective.html

Oh, this is awesome - thanks for the detailed information folks. I'll check this out when I get home later and hopefully can solve the issue without that pump :)

Ok, so it seems like I've figured out the problem (thanks greatly to you folks!). Useful when you know what to look for!

I just went to remove the washer and cotter pin to find that they are completely missing, so I can just pull the head of the wire off the assembly with my fingers. This likely explains the high idle when the engine is at operating temperature too I expect?

Full disclosure: I only bought this car a couple of weeks ago - pleading not guilty to screwing this up!

Are the missing pieces difficult to come by new? Seems I need to order a few bits...

Thanks again! :)

Not at all. It's just an ordinary flat washer and small cotter pin. Both of these can be sourced from commonly available stock at a hardware store, or maybe even in your existing collection of random stuff in the garage.

The washer's hole should not be too large, just large enough for the pin on the lever to pass through. And the cotter pin just has to be small enough to fit through the hole it goes through. If you can't find cotter pin that small you could use a piece of steel wire inserted through the hole and bent so that it can't come out.

This your first Benz? Pics?

Ah, perfect - looks like a trip to the hardware store after work tomorrow then! Thanks!

I've had a few W123s over the years and about five years ago I had a W115 240D which I sold and always regretted. Glad to get back on board! I'll post some photos of this one shortly. It's definitely had some care in it's time (any of these that have survived this long in Canada have had to I think!) but also has had some neglect too. It's a rolling project though so I'm happy it's not stuck in a garage permanently!

Here's a couple of photos:

https://i.imgur.com/6jjHmnR.jpg

https://i.imgur.com/R7IXRfF.jpg

Funny - Our cars are twins. Mine was European Delivery car. I added the Euro lights and bumper myself (still need to do the rear). What color interior does yours have?

http://www.peachparts.com/shopforum/...017_w115-2.jpg

Oh damn, what a beauty. Where did you come by the grill badges? Would love to add those on mine.

Interior wise - it's got the tan (leather or faux leather?) seats and rusty coloured/orangey carpets. Currently the floor is bare as I'm in the midst of rust protecting the floorpans. I think the previous owner added new door seals etc, but didn't bother to dry out the carpet and underlay - carpets have all been drying on the balcony and isn't going back in until everything is sorted properly :)

Hey, your car looks nice, too! My car's interior is "Bamboo". Sounds like yours is the same. You've got a sunroof apparently, which my car does not. Something I REALLY appreciate about my car is the lack of that troublesome central vacuum locking system.

As for the badges (we don't need no stinkin' badges!), I got them from friends. But you can find them on eBay and other places too. Sometimes they pop up in the classifieds on this site.

http://www.peachparts.com/shopforum/...2&d=1553108690

Oh yes, same interior for sure. Beautiful photography too by the way. I love the lack of the big fog(?) lights too, especially with the Euro bumper. Great looking car.

Mine doesn't have central locking either fortunately. One less thing to go wrong. Sunroof appears to seal nicely which I'm pretty happy about. We're having a pretty great end of winter/start to spring up here too so it's been nice cruising around with the roof open