Am now a proud owner of a cat 112 grader =)

can someone help me with regards to year of manufacture please? S/N Chassis: 3u4412
engine tag: 81c39

Thanks,

Newbie Nathan from New Zealand

My book says 1953

Picked up from dannivirke yesterday, bought it back to feilding, it needs alot of work to get running smoothly, fuel lines & tank are gunked up for starters, looking into cutting top off tank and give it a birthday/remove rust ect from tank.

Thanks Neil.

i dont suppose anyone could explain/provide diagram on the fuel pump check valve assembly? have started cleaning up fuel lines ect but cant quite picture how this thing goes back togeather, have ordered service manuals ect off ebay but they are a couple of weeks away, dont mean to be a thorn in someones side...

Do you have direct electric start or pony motor start?

I'm wondering what the fuel pump check valve is. There is a fuel pressure bypass/relief on the inlet of the transfer pump that gives trouble on all the pony start machines. I would think it was also used on direct start models as well, but they also have a hand primer pump installed somehow which will have check valves in it.

The standard bypass/relief valve is in the fuel line inlet adapter block held to the bottom of the fuel transfer pump by two bolts. It is installed with the spring in the hole drilled in the cast iron block and the poppet sitting on top of the spring with the plastic/rubber seal pointing up so it seals against the surface of the fuel pump casting. This casting must be flat for the poppet to seal properly. It can be carefully filed and polished smooth if needed or a milling machine would be the trick.

Yes the standard bypass/relief valve, have cleaned up the valve & put back togeather, the whole fuel system is full of crud. it has an aftermarket fuel filter between fuel tank & transfer pump, but has no filter inside the transfer pump, there is a big open cavity for one to put in there. is it safe to test run runinng only this aftermarket filter or should i be hunting down a transfer filter as well?

It is 24v direct electric, unsure if origional or not, starter/solinoid are in poor condition, wiring to batteries has been fiddled with by previous owners, will have to get wiring tidied up/replaced & go from there. have only seen this machine running breifly by tow start, fuel lines were that bad it would only run a short time and splutter out. there are how ever 2 holes in the hood to allow for pony motor & a big hole in the casing beside starter where you can see the flywheel.

would love to know if there are any 112's 212's or 12's floating around in new zealand still? restored or sitting around it would be interesting to view other machines

Since the original design fuel system of the D315/D4400 4 cylinder engines had no pre-filter ahead of the transfer pump, I think you would be fine with just the aftermarket filter in-line.

I assume you have already drained and cleaned the fuel filter tower and replaced the filters. This is important because the bypass passage that the poppet seals comes down from the unfiltered section of the filter tower. It should not get sediment as it comes out the side of the tower instead of the bottom, but the fuel that recirculates is still unfiltered and any abrasive particles circulating with the fuel will wear the pump gears and housing over time.

Do you have any pictures of the engine and transfer pump? I haven't seen one with a filter in the transfer pump. Wondering if you have a repower or if the "down under" version of the graders has that where ours didn't. Pre-filters seem to have came out on equipment after about 1960 here with the introduction of the D333, D330, D320, etc