Tips for getting left-most bolt out of oil filter housing?
 

I've got a pretty bad oil leak in my 1984 300td that is most likely coming from the oil filter housing. When the engine is running and warm I can see oil start to puddle pretty quickly under that section of the engine. When underneath the car the rest of the engine is dry except below and behind the oil filter housing.

I tried tightening the bolts to see if that would make a difference, but they were pretty already tight and the little bit I was able to tighten them didn't stop the leak.

Assuming I need to replace the gasket does anyone have any tips for getting the left most bolt out of the housing? I'm able to get at the other bolts with a 6mm hex ratchet and a stubby hex wrench for the one closest to the steering box, but I can't get anything to work on the left bolt that is behind the lower oil line (I did remove the oil lines and moved them out of the way).

I'm talking about this bolt:

https://2gdomq.bn1304.livefilestore....&cropmode=none

I seem to recall needing to custom cut a hex wrench extra short in order to be able to get access to this bolt


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The bolt directly right of the one I am referring to requires a cut hex wrench since it is really close to the steering box, however I wasn't able to use the same on the bolt i'm having trouble with. I've tried multiple combinations of ratchets and break bars and I can't quite get anything to seat right in that bolt.

I don't remember but it came out on my 84SD. It looks like the head takes an allen wrench. If so, try cutting up a right angled allen wrench and tapping the long leg into the bolt. (Tapping helps seat the allen head wrench. You reallllly don't want to strip it.) Use a socket on the other end to turn it. I have a few metric allen sockets but also several legs of various lengths and size that I use when I don't want to grind on a socket.

I do remember that this wasn't on my list of favorite jobs. You may want to consider some of the cautions in this thread when you do get the bolt out.

http://www.peachparts.com/shopforum/diesel-discussion/328295-leak-free-617-a.html

It might be that the bolt is full of debris that it won't allow the 6mm hex to seat properly. Or... the bad news... it is stripped.

This job is a PITA, I've done it before but on a W116. It might help if you can raise the engine some if the steering gear is in the way, or unbolting the steering gear and letting it drop down some.

There is a thread somewhere where it was said the Steering Box was removed to gain acess. That sounds extreme but you cannot torque the stock bolts as there is little room for the head of a torque wrench in there.

Also this is one of the jobs where it is a good idea to use the proper torque.

If you unbolt the engine from the motor mounts, you can lift to provide additional clearance.

Dkr.

Is it possible to just remove the pump casing and let the plate stop in place Then after its removed, and if it will come off you can get at the allen bolts after, if need be. Or remove the brass nut thats in front of it,

dumb question, but if i'm not going to replace the motor mounts when I lift the engine (they are new in the last 3 months) is it better to unbolt them from the single bolt at the bottom or the two bolts at the top? Or does it not matter?

I found that having the top bolts loose was necessary to get the single bolt started correctly. I forgot who posted that but you don't want to strip the threads or head.

I think it is easier with the oil cooler lines removed, and out of the way. You can then get a tool in there. Agreed on raising the engine on that side.

Lifting the engine a few inches did the trick, I was able to get a good angle that allowed hex head to seat deep enough. It looks like a previous owner possibly rounded out the tip of the bolt head, so I really had to pound the hex head in and thankfully was able to break it free without rounding it out further. I'll definitely use a new bolt when putting it back on.

So now that the housing is off, what else should I do while I wait for the gasket to arrive? I.e. what other jobs are easier to do with the housing out of the way. I was thinking drip timing the IP might be easier.

Make sure all stray pieces of the old gasket are removed from the surface and that none of the pieces ended up in the holes in the block. Especially the hole where the Oil goes from the Filter to the Engine as any pieces will not be filtered and go to the bearings.

When you are done tape over that hole so nothing gets inside till you are ready to put the Oil Filter Housing back on.

In one of the threads someone recommended taking a sharpening stone and going over the block surface to be sure it its flat. However, if you use the real Mercedes Gasket it is a very sophisticated in construction it ought to be fine as is.

I used a very light rubbercement type gasket sealer/adhesive. I felt the need to have something to hold the Gasket in place on the Oil Filter Housing as space is thight (and besides that I am a pessimist and commonly use gasket sealant of some sort anyway).

Thanks, good advice.

Is there any reason I couldn't/shouldn't soak the housing in a bucket of warm dishwater soap for a few minutes to help clean it off? Or would that present an danger to any of the internal passages in the housing?