240D vacuum leak.

[Glinko]

The door locks and shut off on my mercedes do not work. My question: is it a difficult task to find the cause of the problem without a vacuum checking device like a Mityvac?

When I purchased the car I found two new parts in the trunk; a shut off valve and a vacuum pump gasket. Is it an arduous task to replace these parts, or can a weekend guy like myself do it in a day?

EDIT: let's change the term "weekend guy" to "clueless idiot"

[dkveuro]

Originally Posted by Glinko

The door locks and shut off on my mercedes do not work. My question: is it a difficult task to find the cause of the problem without a vacuum checking device like a Mityvac?

When I purchased the car I found two new parts in the trunk; a shut off valve and a vacuum pump gasket. Is it an arduous task to replace these parts, or can a weekend guy like myself do it in a day?

EDIT: let's change the term "weekend guy" to "clueless idiot"

I hunt for leaks with a electric vacume pump hooked into the port on the booster line.

There is a vac' reservoir on top of the fuel tank you get to in the trunk.
I usually find the gas door vac' acctuator is leaking...why these go first is not obvious....maybe they live to close to sheet metal....BTA, so do the door acctuators.......Hmmmmmmm

Drivers door vac' slide is usually okay...also have found broken hose in A pillar door jamb..

(BTA....But There Again.)


______________________

I think dkveuro has had bad luck with the fuel tank flap diaphragm. My experience is that none of them are more likely to fail than any other. If the fuel door one is failing more often for you it is probably murphy's law since that is the most challenging to replace.

Check to see if there is any vacuum being developed by the pump. If the power brakes are working okay then the pump is working okay.

If vac is being made by pump check all connections at firewall near oil filter first. If it won't hold vacuum there, go to the drivers door. Just keep moving along until you find the leak. A Haynes manual will give you a vac schematic for $20 or so.

Good luck,

[cgryphon]

Just found and fixed a vac leak in my 240D using this thread, Vacuum help?
and in particular, the advice from dmorrison (thanks Dave!). I just started at the fire wall and kept working my way back. Make sure that you look at all the junctions logically (you will find them under the carpet, under the black plastic protective channels) and use your golf tee to isolate components properly as you test them. Search, read, and then dive in. Things will become clearer as you go. I can’t imagine you can do the job without some type of mity-vac tester. I borrowed one from our plant engineer at work.

I got lucky twice. 1st, I found the problem early in the trail at the lock actuator on the passenger door. 2nd, I went to my indy to get him to order the part for me, he rummaged around in a box, and handed me one, NO CHARGE!!!

Bonus feature! You get to learn how to take the door panel off. Look in the sticky's at the top of the forum for link's to the online manual with pictures at
"skinnerbox" to learn how to do this. It's easy, once you know how.

Clay

[dkveuro]

Originally Posted by LarryBible

I think dkveuro has had bad luck ....
Good luck,

Story of my life.......!

[leathermang]

"I usually find the gas door vac' acctuator is leaking...why these go first is not obvious...."

I am pretty sure I have seen a TSB title listed on Alldata.com addressing fixing that particular sore spot....

[Glinko]

so I'm going to need a vacuum tester...dang. Can I find one at Autozone or a similar store, or am I gonna have to wait for it to come in the mail?

Also, um, this is embarassing, how will I know if the power brakes are working or not? Would they be very stiff or hard to engage? I'm not sure if I've been driving the car without them ever since I bought it.

[JimmyL]

Originally Posted by Glinko

so I'm going to need a vacuum tester...dang. Can I find one at Autozone or a similar store, or am I gonna have to wait for it to come in the mail?

Also, um, this is embarassing, how will I know if the power brakes are working or not? Would they be very stiff or hard to engage? I'm not sure if I've been driving the car without them ever since I bought it.

A Mityvac can be had for $26 to $32 bucks at Pepboys and the like. The plastic one works just fine.
If your power brakes aren't working you will feel as though you are having to cram the brake pedal through the firewall almost to the radiator. (ie: very hard to push)
Vacuum testing is easy and gives you an initial sense of accomplishment, then you can move on to bigger and better things.

[Glinko]

I see.

I've already mastered the baby stuff like fluid changes and the like. Want to learn more about cars though because this guy in town charges almost 100 dollars an hour for labor

That, and I feel like a loser when my friends are looking under the hood of a fast car and admiring all of the...stuff...while I stand there with my arms crossed and say "hmm..yeah, that's a big engine there I guess."

[Glinko]

Hmm...I paid attention to the door locks today as I went about my business in town. They unlock just fine, whether the engine is on or not, but they will not lock.






Also, the upshift from first to second gear is very rough, the car jolts when it shifts (subsequently I have not allowed it to shift on its own for quite some time, it is to my understanding that it's actually better to shift it manually once the tranny starts to poop.) There is also quite a bit of lag between shifts, like 3/4 of a second when shifting from 2nd to 3rd, and about half a second when shifting from 3rd to 4th. May this be related to my vacuum issue?

Let it be noted that I've been shifting it manually for quite some time, so the lag in between shifts is considerably better; right now I'm only referring to what happens when I put it in drive and let it shift on its own.

Originally Posted by Glinko

May this be related to my vacuum issue?

I know it can on the 80’s models, I’m not sure on the older models. It helps to know what year your car is

LarryBible is the man with this stuff

[Glinko]

Alright, I bought some kind of vacuum checking device at Autozone (it's not a mityvac, it's something else.)

Now, I've looked at the diagrams in the sticky on top of the forum, but I'm still confused.

How do I know which tube is going to the door locks? I've found a cluster of vacuum tubes going towards the dashboard, that are being held in a cluster by a rubber piece (about the diameter of a dollar piece) that sort of resembles a distributor cap. It is located above the steering box and whatnot, about eight inches to the left of the fuse box; is this what I'm looking for?

Also, if the vacuum checks out fine, then I guess I must check the valves for the door locks; how? Do I have to take the interior panels off of the doors? How do I do that?

[dannym]

You can rent a mity-vac at autozone for nothing.

Danny

[Johnhef]

Solid Yellow is the main line to the drivers door. Yellow/gray is to the reservoir. From the drivers door master switch, yellow/red is the lock side, yellow/green is the unlock. Pull up both front carpets, under them youll find a long hard black cover on both sides. take those up and you'll see your vacuum lines and their splitters. Experiment around by plugging your tester into various connections there and pump away and see what works and what doesn't work. It also helps to label which lines go where because when you find your leak and fix it, something else is bound to fail down the line.

[Glinko]

pump away?

my vacuum tester is a dial with a hose on it, and a couple of adapters....

bought the wrong thing?