Engine/Transmission (1998.5 - 2002) Expansion Plug -- Pin Hole Leak

[Neal Cassady]

Here is an update on the earlier thread:



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=29367



The leak is caused by a very small pin hole where the cup part of the plug meets the wall of the plug. Looks like someone drilled the hole with a 1/64" bit.



I am going to try to plug the hole before attempting to pull the plug. If nothing else it should be able to get me to Cummins after New Years without spraying the engine compartment with coolant.



Thinking of using some epoxy or cold welding compound, looking for some advice.



Thanks,

Neal

 

[lmills]

I would try the epoxy as a quick fix. Just remember to get the surface totally clean off oil and grease.

 

[Steve Campbell]

could you put.....

your epoxy on a screw of the appropriate size and just screw it in for a temporary fix?

 

[illflem]

Steve's advice sounds best, maybe even permanent with a stainless screw. Think with just epoxy you will have a hard time getting the area clean/dry enough to stick.

 

[Shovelhead]

The "pin-hole" is probably caused by corrosion on the inside of the plug that finally ate all the way to the outside. .

 

[Neal Cassady]

Expoxy + Screw

Would be ideal but it would be hard, if not impossible, due to the location of the pinhole, to run a screw in there without distorting the plug and making things worse. Plus I am forced to work looking into a mirror, so everything is reversed, feel like a dentist. If the pinhole was closer to the center I could use it as a pilot hole to run a screw in and pop the plug out.



When I went to the Cummins shop to pick up the replacement plug I looked at a Dodge on the lot with one of the mechanics, he told me they would probably pull the head to replace the plug, way easier to remove and guaranteed to install straight, plus they would check the rest of the plugs.



I think I can get a small wire brush or sanding cone on a flexi shaft and rough up the face of the plug to get some adhesion. Clean and dry shouldn't be a problem. I am going to try some JB Weld and force a little through the pinhole then build up a cap on the inside of the plug. This is a small plug, approx. 1/4" ID. Don't want to future plug removal more difficult. Hopefully the patch will hold long enough I can R/R the plug or a least get it to Cummins without making a mess. I used a toothpick in the hole to move the truck a short distance and it keep the coolant leak to a small weep.



Thanks,

Neal

 

[illflem]

Your toothpick reminded me

Old farmer's trick - redwood or cedar "toothpicks" or stakes pounded into a pinhole leak. The redwood swells when wet and will make a permanent fix. I've done this on pipeline leaks up to 150 psi without even a drip, never tried it on a vehicle but it seems like it would work if the epoxy doesn't.

 

[sag2]

If you want to try the epoxy, get some microfiber (sold by West Marine) filler. You mix it with the epoxy to form a paste as thick as you like. Mix it thick enough and it won't run out before it hardens. Might also be able to find it at a hobby store, but be careful because it might be balsa filler. In either case it is a very fine powder. Works great for filling gaps of almost any size.

Something to keep in mind, if you fill with epoxy, you will almost certainly have to drill it out, and that may require removing the head to do the proper repair.

 

[Neal Cassady]

Number 4 Also

Call me Lucky, while I was cleaning and setting up the job I noticed a nice stain running down the head and block below the same plug under #4. Can't tell about this one yet but it looks like it is leaking around the plug. Looks like a trip to Cummins will be in order sooner than later. Seems very odd at only 37K. Another reason to go 12V. I was looking at a 12V head at Cummins doesn't appear to be loaded with expansion plugs, there has to be more than 20 on a 24V head.







Neal

 

[Neal Cassady]

JB Weld is In

I put the JB in this afternoon. None of my small sanding/roughing flexishaft attachments would fit inside the plug so I roughed it up as good as possible with some plumbers emory cloth, kind of like cleaning up the inside of a copper fitting before sweating. Glued some of the same material to the eraser end of a pencil and roughed up the face. I sprayed some brake cleaner on a Qtip and cleaned it several times.



I put some JB in the pinhole with a toothpick then gradually filled the inside of the plug and tried to compact it with a dowel as I went. It was cool enough that the expoxy had some body to it. I cleaned up the excess as much a possible so official plug removal wouldn't be more difficult. I have a light bulb hanging near it, once it sets a little more I am going to move the bulb closer. Fortunately I have some time off so the truck can sit for a couple of days before I test the patch.



Doesn't look to bad in there, hopefully will adhere well enough to hang on for I while. JB Weld works for a lot of things but I haven't had real good results in this type of fix, hoping for the best.



Thanks for all the tips, I will post a follow up after I test it out for a while.