Hey guys 89P 980B 1975 (forgot this ones serial # maybe 3000) It's used for snowplowing mostly. It loses prime after sitting for a long time. Sometimes its fine for a week or a year and then it creeps up again. It fires up but fuel pressure drops right off and it stalls. Pump up the primer and it's good to go. I've tried to chase this down before but' it fixes itself before I do. No rhyme or reason two winters ago I had to prime it everytime, last winter and this summer it never happened. This week it's back any Ideas? Thanks Randy
Take off the small fuel return line and clean it out good. I wonder if the intermittent problem is more often when the fuel level is low(around half tank) rather than with a full tank of fuel? The fuel return line keeps the pump free of air on any engine set up were the fuel level can get below the level of the pump. If the fuel tank is high a line leak is less likely to cause the pump to pick up air than if the pump must lift the fuel from a low tank. later Bob
Hey Bob It's not dependent on fuel level. I haven't looked at the return line I'll check that out when I get a chance. Thanks Again Randy
Bob I checked out the return line. I could blow through it so it seemed good. I blew it out with compressed air to be sure we'll see how it goes. Thanks again Randy.
If that line is clear it will deal with a great quantity of air picked up by the pump. Just an after thought, you did make sure the fuel is getting out the fitting to the line didn't you? Got the PM and replied. Later Bob
Could anyone let me know about the official consumption of cat980c, cat 966c, cat 966r wheel loaders? I'd really appreciate if you could help me!
It sounds like a fuel transfer pump to me. It will be located near the fuel injection pump, I'm not sure exactly where it is, but if you can trace the fuel lines from the tank, you should encounter a small pump that the line from the tank runs into. The fuel outlet line is where you need to look next, if you can find that line, plumb a pressure gauge onto that line. You should read about 65 psi on the gauge. If you read 0 psi the pump is bad and needs to be replaced, if you read anywhere around 5 psi start checking for blocked lines anywhere in the fuel circuit. I hope this helps.
Update. Well not much snow to push this winter but when we did use it started with no problems. Knock on wood!!! Thanks Bob for the help. There must have been some restriction in the return line. Randy
I'd be thinking its the transfer pump, not sure about the 980B but the 3306's in the 966's used to have around 32psi when the transfer pump is doing it's job