Oil & Fuel Removing Fuel Petcock With Tank Installed?

[old515]

Hi

Here's a link to the NH parts diagram of my fuel system. Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
The tractor is a 1978 515 which I understand uses the same three cylinder diesel as a ton of Fords, and from what I have read here is basically the same as a 4600(?).

I am having problems with my fuel line clogging at the tank. (Machine stalls, unhook fuel line at filter, no flow, blow air back into line towards tank, then it flows again.) If I keep the tank above half it mostly stays running.

I am considering removing the petcock/shutoff/tank filter with out removing the tank from the tractor. I am a bit nervous that I might end up regretting this if the petcock breaks. It looks like there's probably just enough room to crank on the valve to get it turning out.

Does anyone have experience with removing these petcocks, do they come out easy or hard?

I siphoned the tank empty today and was able to see the filter laying loose on the bottom of the tank, so more then likely that's my problem.

Thanks


Ford 515
Tractor # C571210
Model # DV214C
Unit # 8D11B
Engine # 8B02B
Trans # 8A10C
Rear Axle # 8A30C
Hydro Pump # 8A28A
Hydro Lift # 7M19B

 

[TractorTech]

Old515, you are correct in the tank filter off of the petcock being your problem. The petcock is relatively easy to remove and shouldn't break off, however, like any plumbing work, Murphy's Law is always present.
When you do get the petcock out, remove the stem retaining hairpin(12), unscrew the stem and replace the oring(11). This oring dries out and allows diesel to leak.
Good luck.