I have a John Deere 624H loader with a 6068 engine. I keep getting air in the fuel system. I've replaced all of the rubber lines, all of the o rings, replaced both fuel filters, and the transfer pump. Anybody have any other suggestions?
How do you know its air in the system?? hard start? have to use the hand primer to start? Is it an in-line injection pump?? or electronic rotary.. if its a rotary and its skipping & blowing smoke its not air, its a broken accumulator spring inside the inj. pump..
Metal fuel lines can wear through under the those little straps that are wrapped around the tubing. It's happened to me. Engine would start hard and serge each time I started it cold.
more info It is a nippondenso inline pump. It will start then dies acting like it is running out of fuel. I use the transfer pump hand primer and bleed the air out at the secondary filter. Always has air in it. All new fuel lines from tank to secondary fuel filter. From secondary filter to injection pump they are steel and show no sign of leaking.
Check the overflow valve on the return line of the injection pump.. check for a broken or weak spring..
Thanks, I ordered a new over pressure bypass valve. Hopefully that fixes the problem. The spring seems to be very weak.
Did you order it from a fuel shop or Deere?? Probably cheaper from a fuel shop..
Is there junk in the fuel tank? Sounds similar our 624H has the fuel filter housings with the black plastic caps on top of them and they screw off cause they can get junk in them that don't get into the filter
I'm sure Deere overcharged me, but I have an account there and they will ship directly to me. I live 150 miles from the closest fuel shop. They charged me $180 dollars for it.
The fuel tank appears to be clean. I took the primary housing apart to check the pump diaphragm and didn't find any junk in the top. Usually find crude in the diaphragm if the tank is dirty.
Your probably right with the cost from Deere.. I think they are 75.00 from a fuel shop..
I have a Massey Ferguson Perkins diesel, running a pump on the PTO. It would run for awhile and quit on its own. I had the injector pump overhauled, thinking that was the problem, but it was no better. I talked to the injector over hauler thinking still it was the injector pump. He told me no, it had been tested and was fine, but the engine was running out of fuel because when I cracked the injectors after it quit, I could get air. Replaced all filters, removed and cleaned tank screen, still had the problem. Finally found the problem to be a partially kinked metal fuel line. The injector pump (positive displacement) created a vacuum due to limited fuel flow and sucked in air from somewhere. Replaced the fuel line and it has been running fine ever since. A small kink in a fuel line can cause the lack of fuel problem.