D8 fuel system help

OldRedFord · 2026-09-24T00:07:38.000Z

I've got a 1956 Caterpillar D8 15A series G that I'm trying to get running again after sitting stuck for about 7 years. I did have it running twice during that time but maybe 30 minutes total. Prior to this I have ran this dozer clearing my land so I know it's a decent runner. I'm trying to reprime the fuel system. At some point in the past the torque converter was replaced and new fuel lines ran so it's slightly different from factory from what I can tell. I pressurized the fuel tank and spun the engine over. I'm getting fuel to the torque converter fluid filter housing and also leaking a lot of diesel at the converter from somewhere. I can not get any fuel up to the filter housing on the injection pump, but I do get sir when I pressurize the tank. Im not sure which line is supplying fuel to the converter and taking fuel away. The T fitting in the upper left of the first picture goes to the back side of the converter. The line runs as follows Leaves fuel tank the T fitting to the back of the converter Other side of T fitting to fuel pump under injection pump The 2nd picture that line comes from the torque converter filter housing and starts at the fuel pump under the injection pump. I would like to isolate the torque converter to try to get the engine primed and running first using a pair of valves and when I get the engine running open the valves so the entire system can flow. Here's a clip of getting my D8 out a few after I had gotten it buried to the top of the tracks seven years ago. Only took a PC400 to get it out.

Old MagnetJunior MemberSep 28, 2026#21

The Service Manual for the 14A/15A does a pretty good job of showing the torque converter innards. If the TC seals are shot that's a bit of a problem although I believe I heard they are still available from "Twin Disc" for a "ransom".

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