My case 621d with a 5.9 Cummins has been seriously lacking in the power department. All new filters, no smoke, no intake restrictions and seems to have good boost. All the normal quick checks like shutoff solenoid and collapsed intake have been made. Loader Starts good and runs well until I push into a loose stockpile and use hydraulics, even if at full throttle it will pull it down to 11-1300 rpm. It seems to run very well until hydraulics come into play kinda like an axial pump stuck full tilt. I’m going to run a few other checks tomorrow before I load it up and drag into the shop for a deeper dig. This one has me scratching my head…
Before you go ripping things apart, check the supply pump.. There’s usually a spot on the filter head to tap a gauge in.. Should read 5 psi or higher. If u have a problem with the supply pump, it’ll start and run well, but once u call for any heavy lifting, it’ll fall on its face. If it checks fine @ low idle and FULL LOAD.. send me a prvt msg.
Thanks for the input, it’s on my list to check, but I’ll start there and let you know.
I've had trash get into the check valve on the supply pump to where the pump can't supply fuel volume or pressure. Do what TPG said above.
I'm not used to the 5.9 in equipment but used to work on Dodge trucks. Does this have the inline P7100 injection pump? It has been a while since I worked on them but if I remember correctly there is a fuel pressure regulator on the return line fitting from the pump to the tank. I think it is part of the banjo bolt It would not maintain pressure and you would get low power. If it isn't the inline P7100 pump then disregard. If it is newer and uses the VP44 I might be able to supply some more ideas but I don't know if that pump was ever used in equipment.
Have you resolved the issue with your loader?
Sorry, for the slow response guys. I haven’t been able to do any testing yet due to other priorities getting in the way and away from the forum. I plan on tomorrow working on it and should have an update on what I find.
Hey guys, finally got back on the loader with some testing and a few replacements due to being untouched with almost 7k hours. Tested fuel pressure with original lift pump at 17-20 psi and replaced with new OEM to end up in the 25 psi range. Regulator bolt at injector pump also replaced as safe measures. All fuel hoses and filters changed. I don’t believe the p pump was keyed ? Possibly slipped time?
the torque on the drive shaft nut is 200 ftlbs..if it’s a P7100 pump.. Degrease the shaft and the drive hub.. blue loctite on the threads and torque nut to 200 ftlbs… weather it’s keyed or not.!! There should be a timing pointer on the intermediate gov hsg.. there’s a cap on it with hexes.. I forget the size..22mm.?? (Adjustable) I take it changing the overflow valve and supply pump and lines didn’t help.??
No sir. Zero change. I will inspect timing marks tomorrow and update on what I find.
There should be a “push pin” under the pump and a pointer on the pump governor.. When the pin drops into its hole, that’s TDC.. THATS WHEN the pointer should be dead center in its hole.. Good luck..
I always remove the timing pin housing so I can see the hole in cam gear, then push timing through enough to contact hole. You may have to turn engine slightly to align screw holes. There is a plug on the side of IP with a plastic timing pin to lock pump. Pull pin out of cap and flip over and insert into pump if it won’t go then pump is out of time.