clogged fuel lines on 4020

[jenkinsph]

3020's but not 4020's had side by side fuel filters. Also 2 cyl diesels had side by side fuel filters

Notice I said "some of the Deere's" speaking in general, my 3020 must have had the side by side filters, honestly don't remember that has been a few years. My current smaller 820 has side by side filters with lower glass bowls.

I agree with the problem likely being air in the system as I don't think the trash in the fuel line would cause the almost instant problem after changing the filters but is in line with air entrainment at the injector pump. If the OP didn't know to bleed the air from the top of the filters prior to attempting to start it I think it is a "given".

 

[dminer]

It is usually a good idea to prefill the filters with fuel before installing whenever possible. It makes for a lot less air to remove from the system.

 

[roush9799]

You can't prefill the top one, it is upside down. You have to open the top bleeder and pump and pump and pump and finally you get fuel out of the bleeder. It may take 200 pumps or more to get them full depending how strong the primer pump is. Once you get fuel to there it should start unless you have air pumped in the lines. If so loosen (just have to loosen it a bit) the farthest one from the filter and crank it over a bit. Tighten it and if it starts your good, if not go to the next farthest and on down the line. It will finally hit once you get enough air out.

 

[Tx Jim]

You can't prefill the top one, it is upside down. You have to open the top bleeder and pump and pump and pump and finally you get fuel out of the bleeder. It may take 200 pumps or more to get them full depending how strong the primer pump is.

Unless one cheats like I do and blow short bursts of compressed air in fuel tank neck with a rag stuffed in hole to block escaping air to force fuel into the top filter. My finger doesn't get as tired hold air blower trigger down as pumping lever on the lift pump.

 

[owens73]

I didn't see the rest of the responses before I went back to my farm yesterday to try and get the tractor running again. I opened the bleeder valve on the top filter and pumped the primer until fuel came out of the bleeder valve. The tractor started right up and ran well for a couple seconds, then died. It did that 4 or 5 times. I then left the bleeder screw backed out a bit and started the tractor and it did the same thing. So, I need to bleed the injector lines?

 

[owens73]

I said I pumped the primer and then the tractor started and ran well for a couple seconds then died, and "it did that 4 or 5 times." I only pumped the primer one time, before starting it the first time. The other 4 or 5 times, I waited a few seconds after the tractor died, then cranked the engine.

 

[Tx Jim]

Before loosening inj lines I'd suggest loosening supply line at inj pump and pumping lever on lift pump until air free fuel squirts out and then tighten nut on line.

 

[roush9799]

Before loosening inj lines I'd suggest loosening supply line at inj pump and pumping lever on lift pump until air free fuel squirts out and then tighten nut on line.

Worth a shot, but since it's dying, the air is probably in the whole system between the injectors and filters. You may luck out and get enough air out that it will start and keep running till all the air is purged out.

 

[jenkinsph]

I agree with Tx Jim do the easy stuff first, and the injector pump inlet is a good bet. I should also mention that Jim is a very helpful retired Deere shop foreman and tractor mechanic with lots of Twenty series experience.

 

[Tx Jim]

There's also another possibility that the fuel return line fitting is plugged with debris. A plugged return line will allow engine to start/die,start/die