EXTREME Frustration with '97 E300D Shutoff Valve - PeachParts Mercedes-Benz Forum

AGx · #1 10-31-2006, 10:38 PM

I have a 97 E300D that had the original fuel lines and a couple of them were leaking. Thanks to you very helpful folks I removed the intake manifold, replaced all those lines, reassembled and cleaned the engine and my quite rapid fuel leak went away.

A month or so later, though, the smell of diesel is again hovering around the front of my car. Using a white paper towel (white glove treatment), I discovered that there was a small seeping drip keeping the bottom of the shutoff valve damp. I used a T30 socket and managed to fail miserably in removing both of the screws that retain the shutoff valve; their heads now a little rounded - I was able to get a grip on the aft screw head using Vise Grips, but the front one is defying all efforts to remove it. I tried using "Easy Out" reverse threaded removers and, failing with those, resorted to Screw Out "damaged screw removers". But, the screw has defied all my efforts to budge it - that rear screw was VERY tight.

I'm running out of ideas - I've read that some of you, too, have had problems with those bolts, but haven't found a single reference to the methods employed to break them loose. Can anyone here provide some enlightenment. Also, what is the preferred method of engine compartment cleaning among the users here?

Thank you,
AG

Monomer · #2 10-31-2006, 10:49 PM

spray with PB and wait a couple of days.

try again.

AGx · #3 11-01-2006, 01:50 AM

I used a spray from CRC: Freeze Off Super Penetrant. This company has a good rep in the electronics and computer industry... 'course, that means nothing to a stuck bolt in the auto industry. I've applied it several times over the past week or so with no luck. And I inserted a T30 into the bolt head and tapped it pretty well with hammer blows during that time, too.

I guess it couldn't hurt to try some PB, I've used that in the past to try to get some brake lines off an old diesel Suburban... Sadly, I had not a lot of success there, but I did get several connections loose. Hopefully it'll be a LOT better than the CRC FO spray - it certainly smells more aggressive.

I'm afraid that the last miracle tool I employed - that Screw-Out or Screw-Off - may have further damaged the head of that screw/bolt to the point that I may have to slot it or otherwise modify it in order to remove it. I suppose I can cut the (GRP) plastic housing and pull that screw with a Vise Grip, but that seems like crude and wasteful very last-resort option. I should be able to come up with a whole lot of interim solutions in the meantime.

These cars... sometimes I know how Ralph Kramden felt "To da moon, Alice! To da moon!" I'm usually pretty good at removing problem fasteners, but this &^%$# thing has me feeling pretty helpless/stupid and a little screwed.

After this, I get to try to fix/replace that combo turn-signal switch - it switches on hi-beams when auto-cancelling a turn signal and the (little rectangular, plastic) cover on the column pops loose - the stalk pops out about an eighth of an inch or so from it's socket in the switch. And I think my K40 is going to need some soldering... soldering, a skill in which I, at least, have a LOT of experience. Then, maybe brake pads... I sure hope that's all for a while.

All assuming that I can get that confounded shutoff valve's mounting bolt out, of course.

Thanks guys,
AG

#4 11-01-2006, 06:40 AM

AGx,
I did not have near the problem that you have experienced, but I did have problems removing mine. The reason.....some @!#$!@#$ at Mercedes went with some screw from a company that has the shallowest Torx socket that I have ever seen. Before I reinstalled my shut-off I when to the hardware store and purchased good allen head screws.

Someone from Mercedes needs to be dope slapped for this one.

mbdoc · #5 11-01-2006, 08:31 AM

JUST drill the head of the bolt off.. then the solenoid will come off.

At that point the bolt should screw out.

Those bolts do not have to be tight as there is an o-ring to seal the solenoid.

AGx · #6 11-01-2006, 08:39 PM

Wouldn't you know it, I followed M.B. Doc's advice and drilled the screw - I couldn't get a perfectly straight shot at it but was only off by about 5 degrees or so. I put a good hole in the head of that screw and the drill got pretty hot. I noticed that the shutoff valve moved so I switched to one of those Power-Out bits and it came right out!

Then I picked up some hex-head replacement bolts - I had ordered the MB parts but when I saw those &^%$#$ shallow torx heads I just couldn't see fighting with those out again. I'll reassemble everything tomorrow and, hopefully, not have any new fuel leaks from the 3 (almost new) hoses that I disturbed during this process. I lubed every O-ring with silicone grease before assembly and they popped together easily.

I actually thought I was going to get the whole thing done in 3 hours or less until I ran into those 2 screws... based on how long it took to change those 6 fuel lines.

Thanks again for all the advice guys, I really couldn't have done this job without it,
AG

uberwgn · #7 11-01-2006, 09:37 PM

I went thru this nonsense two weeks ago. Ended up having to remove the IM to gain adequate access to remove the rear screw. Quite annoying. I put a little anti seize paste on the new hardware assuming that o-ring will have to be replaced again sometime in the future.

it's nice being leak-free