Hello Tony, I've done two of these D4 rebuilds now and never used 2 gaskets, I'm not sure why the parts book says that but there is done jiggling needed to line up all those water housings on the D4400 for a snug fit, particularly on a old badly rusted engine, my D4 7J had rotted the gasket flanges badly, the fuel tower manifold was so bad I actually made a blanking plate to block the water from getting to it from the water pump, here in Oz burning only diesel fuel, I figured I wouldn't need a fuel heater.

On the top radiator neck, where it bolts to the radiator tank I've used rubberized cork successfully, it seals better than the regular hard gasket material, particularly if there is some rust erosion on the gasket faces, and there usually is.

I think I have some spare gaskets here, I'll try and get some measurements for you.
Mike

Hi Team,
my thoughts on the two sets of double gaskets offered by the Parts Book is that some times there can be a stack up of tolerances that may result in more than one gasket gap at either end of the heater elbow.
The correct fitting procedure for such an elbow is to finger tighten the bolts each end and see that there is no excessive gap evident at each mounting flange and so fit extra gaskets as needed so no undue forces are applied to each flange of the elbow.
As cast iron is not very forgiving of excessive forces, especially when uneven heat and cooling cycles are added in due to the odd shapes of the elbow and its apparent rigidity.

If I was fitting this elbow in the field I know I would be thankful for the ability to shim the joints with the extra gaskets supplied--the client would be unhappy if I had to go back and gets extra or wait for them to be taxied over.

I stand to be corrected.
Cheers,
Eddie B.

I'm sure you are right Eddie, I read in one of the old Cat Service Reports about relaxing the size of the bolt holes in some of those water manifolds to allow a little extra wriggle room to line them all up.
Regards
Mike

That looks nasty Tony, I've never seen one that choked up, at least your gasket faces look OK from here, on my old D4 girls they both had very bad rust damage to the gasket faces.

The trick as Eddie says is to tighten the manifolds all up slowly allowing them to pull together, I used some Permatex Aviation Gasket Sealer on my gaskets too just to be safe.
Good luck
Mike