shutoff valve replacement tips - PeachParts Mercedes-Benz Forum

#1 08-19-2002, 01:55 PM

Hi all,
Well it looks like its time to break down and replace the ole' shut off valve this weekend on the 300sd.
Anyone have any tips to make this job easier from the way it looks on the IP its going to be a pain.
I did read on this forum somewhere that this part can be placed in upsidedown? is that correct and it can destroy the engine if so. well If that is a fact I would guess I would want to avoid that at all costs.
Are there any other types of no-nos I should be aware of ?

Also this little sucker takes some sort of a gasket can I make this peice? partslane does not carry this gasket and I can't get to the dealership due to their miserable short hours.

Thank you in advance for any advice

Jeff

#2 08-19-2002, 07:15 PM

Hey Jeff, this job is a breeze. Gasket should come packaged with unit. The only real tip is:
make note of the position of the hooked extension as you remove the old unit. Then place new unit in same position. Voila!

Good luck.

psfred · #3 08-19-2002, 10:51 PM

Make sure the cutoff lever moves with applied vac to the new solenoid before you start the car -- if it doesn't, you didn't get the lever hooked on properly. You can also test this by pushing the lever down, then holding your finger over the vac line connection -- if the lever stays down until you remove your finger, it's hooked on properly.

If you are still paranoid, keep a 17 mm wrench handy, and if the engine runs away, open the injector lines at the injectors to kill it. You can do this to stop it, too, if the lever doesn't work.

I don't know of anyone who actually had the engine run away, though. More of a problem with the vac governor diaphram.

I did not get a new gasket with the cutoff for the 87 300D -- hang on the the old one in case. If you leave it off, you will get oil everywhere!

Peter

Piotr · #4 08-20-2002, 12:35 AM

ps fred-why are you insisting on unscrewing fuel lines??? my 190 has a manual lever to kill the engine if the valve goes bad. whether you hook the valve right or not, you can always shut of the engine by manually depressing the lever (I did it for 2 weeks while waiting for the valve). On 190 D I had to remove the air filter housing and the bottom of the air intake manifold to get to the valve, but the whole deal took about 2 (leisure) hours to complete. Literally 2 screws (although I had to cut a 10 mm wrench in half to get to them) and it's done. I was told to reuse the old seal-it worked. one of the easiest things on a 190.

#5 08-20-2002, 08:15 AM

Hey guys thanks for the advice...

psfred.. how can I tell if the cutoff lever is working once installed without starting the car? would it be by using a Miti-vac?

Piotr... If I'm not mistaken sometimes if there's a vac leak really bad cauing the engine to take off sometimes the shut off lever does not work, which is famous if the vacume pump went bad

Jeff

deluvak · #6 08-20-2002, 10:30 AM

Just this morning when I turned the key to off arriving at work, my 1985 300D did not stop with its usual suddeness. Instead it seemed to take about a second and a half to ease to a halt. I started and stopped the engine a couple of more times with the same result.

The only thing I've done recently is to adjust the rack damper pin this weekend, which helped smooth out a loping idle when hot.

Should I be concerned about the shutoff valve suddenly not working at all?

Thanks for any suggestions and all the help I've gotten here in the past.

Happy Dieseling,
Dan

Piotr · #7 08-20-2002, 11:55 AM

aaaaaaHHHHHA!! I did not know this!! Sorry.
Deluvak- this is what happened to me for 2 days, and then the valve went bad!!

psfred · #8 08-20-2002, 07:15 PM

Piotr:

The lever connects to the shutoff solenoid, and it is possible for it not to work (or for the fuel to remain shut off entirely) if it isn't connected. As I said, much more of a problem on the vac governor on older cars. If you didn't get the operating rod reconnected, the shutoff lever did nothing.

Jeff:

You can test it by making sure the lever stays down if you put your finger on the connetion after you push the lever down manually. If the lever pops back up, or doesn't make the air puff out of the solenoid when you push it down, it's not connected.

Deluvac:

The rubber connector can break if you twist or bend it while working on something else if it is old, so while the solenoid is fine, the hose isn't, result is no shutoff. Check it, then pull the hose off push the stop lever down, and cover the fitting with your finger. If the lever slowly comes back up, the solenoid is shot. If it stays down, you have a vac problem instead.

#9 08-21-2002, 08:00 AM

Psfred... would the lever your referring to be the emergency stop lever on the engine?
Sorry I'm just a little confused and want to make sure I get all my facts straight in my head before I do some damage.
I'm driving out your way during Labor day weekend and I want to make sure everything is 100%

Jeff

psfred · #10 08-21-2002, 06:45 PM

Jeff:

Yes, that is the one labeled "stop". Much easier repair on the 617 than on the 603!

What part of the Midwest are you visiting? I'm going to be in Carbondale, Illinois, for a collegate Sailing Club reunion -- spent many a happy weekend roasting out in a tiny dingy on Crab Orchard lake twelve or so years ago!

Peter

Ken300D · #11 08-21-2002, 06:54 PM

You should always do psfred's "finger on shutdown valve" test first to determine if it really is the vacuum solenoid that is bad.

------
You can test it by making sure the lever stays down if you put your finger on the connetion after you push the lever down manually. If the lever pops back up, or doesn't make the air puff out of the solenoid when you push it down, it's not connected.
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I had shutdown problems for one day and I thought the shutdown solenoid was bad. Did the above test and it was fine. Turned out to be a bad vacuum hose.

Much cheaper and easier to replace!

Ken300D

#12 08-22-2002, 07:50 AM

Thank You everyone for the tips and help!!!
I went ahead and changed the shut off valve lastnight it was a gravy job.
wow now my car shuts off with the key , so impressive

Psfred... I'm headed out to Indiana over the holiday weekend to more than likely the Ft. Wayne area or Indianapolis. I've decided to move there in a few months and thought it would be a good idea to take a weekend and see where I'd like to park myself.

Well Thank you all again

Jeff