285 priming issues

IFF · May 4, 2016

I am getting to my wits end on priming my MF 285. The tractor has always started right up, no issues. I split the tractor to replace the hydraulic pump. After putting it back together, I changed the oil and fuel filters while I was at it. The fuel filters were very slow to fill with the right hand filter filling much faster than the left. I went through the recommended bleed cycle and have fuel to the injector pump at both lines/ends to the pump. I also have fuel to the middle two injectors. It is very difficult to reach numbers 1 and 4 without removing the fuel tank. I can crank the tractor for 10-15 seconds and it will start blowing from the exhaust it will eventually catch and run for 20-25 seconds and then shut down. It seems as though it will run on whatever fuel is in the lines and then run out. I did replace the lift pump thinking that was my issue. It did not change things. I cannot see and drips of leaks from the fuel tank to the injector pump. I am wondering if I have an air leak but don't know how to root it out. Any suggestions?

IFF

Dieseltech · May 4, 2016

Have two things for you to check, first is the filters. If NAPA or WIX are used MAKE SURE the filter top outer groove does NOT have an O ring in it. That's the filter inlet, an O ring will restrict the flow or stop it completely. Next is the constant air bleed fitting that's on top of a filter base and is connected to the small top injector bleed off line. It may be a bolt or straight fitting, with an orifice hole to bleed air out of the filter base. When it gets plugged trapped filter air can't get out as it should and goes to the injection pump instead, killing the engine. If it's really quiet you should hear the fuel going back to the tank when working the hand primer. If not take the line loose and make sure the orifice is open when operating the hand primer.

IFF · May 4, 2016

DieselTech,

I am using NAPA filters and I do believe I used a large O'ring on the top where the metal filter seats to the filter housing. The filter package comes with three large o'rings. I didn't really pay too much attention to the old filters coming off and assumed that two of the orings went on the top and bottom of the new filter. I don't have time to check it tonight but tomorrow will tell the tale. Thanks.

IFF

285 priming issues

IFF

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Dieseltech

Well-known Member

IFF

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