I'm sorry, that is not a 25, but an unstyled B or 30B

That looks like our Cletrac 25

Zimmermans has a hand hend pump with the right fitting on for a price of150.00
call them at 717-738-2573

Your pics look more like a later HG, check the finaldrive, looking from the side of your crawler, look through the sprocket holes at the final drive housing cover where the little gear(top gear) is inside, if there is a cover BOLTED on there it is OC-3. If there is a little cover or raised area welded on there it is HG.

Please look on the left side of the engine block up at the edge halfway from front to back, there is a small flat spot on the block where the engine serial and model numbers are.<P> Also if you have a 3HI or hgh loader, it is most likely an HG. <p>also if your front wheel has holes through like the sprocket and if the frame is simply cut out where the bellhousing slips in, that would all indicate it is an HG.<p>If you give me the original engine serial number I can get close at telling the year.