Is anyone familiar with the hood mounted auxiliary hydraulic tank? I have seen them on D4's but were they ever mounted on a D2? I looked at a D2 this weekend that had about a 4" mystery hole in the center of the hood. It also had a stiffening plate underneath that was held to the hood with 6 bolts and correctly notched around the pony and main exhaust. This tractor had a factory blade and two hyd outputs running to the rear(2 pipes on each side of seat tank). I was wondering if it maybe had a hood mounted tank at one time.Does anyone has some close up photos of a hood tank mounted?

 

No closeup photos of one on a D2, but I did see one on Pinterest? That does look like it had one at one time, with all of the holes and looks like it had a nice leak at one time!
The bottom outlet would have an elbow/hose that would connect it to the fill side of the hydraulic pump. I saw one on a D6 9U also.JM

I was able to find a D4 photo with the tank installed. 
   

Still be curious if anyone has seen one on a D2 or any other ideas of why that hole would be there??

This is from the #44 parts catalog, form 32888, on the bottom it has the listing for the 40 scraper on a D2, same tank as used on others. Might not be much use loading heavy material, but for light material and spreading would be ok, also there is shown the expansion tank used on the D2 with the #44 for other uses than just the #40.
 

Neil: We think alike. One of these days I will find a decent #44 unit to mount up on the shiny D4 that is getting an overhaul. I foolishly sold my surge tank to a notorious CAT herder/hoarder from Idaho. I fooled him by keeping the steel tube for it though, so a refund might be in order. Hah!