TD55D stalling


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I have a NH TD55D which I have owned for about 20 years. Runs very well but now has a likely fuel supply issue.
The tractor was low on diesel then started to lose power. Refueled and restarted but it now stalls after a couple of minutes at all rev levels. I have checked and partly drained the fuel water separator and also the fuel filter and then primed to remove any air. Checked and cleaned air filter. I have ordered new filters for all of the above as they are overdue for replacement. Tractor starts slowly after about 3 x 10 seconds on the starter - feels like it is priming fuel - then stalls after about two minutes of what sounds normal running. I once had a hole in a fuel line that caused these issues but can’t find anything. Any thoughts on what else to check?


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Not sure what else you might check. New fuel filter and water separator are good moves. If that does not fix it I'm afraid you might have another leak in the fuel line somewhere. Wish I had a clue on how to pressurize the fuel line to check for a leak. I know it's possible but don't know how they do it.


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I may have found the issue. The bleed screw on top of the fuel filter does not tighten completely - little bubbles of diesel continue when I use the lift pump to bleed the air.

Either the screw or the fuel filter housing has a stripped thread. Hope it’s the screw.
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It’s been a while and still working on this. Fixed the bleed screw issue. Blew out the fuel line to the tank and dislodged some gunk - probably a mould or fungus build up. Drained the fuel tank which was pretty clean. All ran fine for about 45 minutes.

Suspected there was still a problem with the tank pickup line so bypassed with a new fuel line to an external tank direct to the fuel sedimenter. Primed and started and runs well for a couple of minutes then stops. Before it stalls the return line to the tank goes from a steady clear stream of diesel to a bubbly stream. So it’s sucking air somewhere. When it runs the motor sounds good until it starts to stave for fuel. Any suggestions on where to next?


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TD55D, TD65D up to TD95D.

55HP 4WD NH tractor sold in Australia. Similar I think to TN series


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The NH parts website I visit has no listing for the TD55. I do know the TD series fairly well, and suspect it's probably a three cylinder version of the larger models of the series. I know the water separators were problematic, and I have replaced a number of them with something totally different, or eliminated them entirely. If you're pretty confident that's not an issue, the seal washers are sound with no air leaks, then I would move to the supply pump. Those are can always be suspect as well. If you haven't already done so, remove the center screw and cover, inspect and clean the internal screen. You may find more of the stuff you found earlier elsewhere. Also, while it's apart, remover the banjo bolt from the tank to the supply pump, remove and inspect the banjo itself. I find all sorts of stuff stuck in the fitting inlets, and the ports in the bolts. Anything there will certainly impede fuel flow.

The stripped bleed screw on the filter base is also common. I've learned to simply replace the filter base as a long term solution. A bandaid fix there will often only last until the next filter change.