420c Henery loader

[lherseth]

I have a 420c with a henery brand loader with a hydreco pump #20115f5b1. After a few loads the loader wont go all the way to the top when its full. The oil is full, does anyone know the gpm and working pressure of this pump? how can one test the pump performance? My problem could be the valves but most think its the pump. :?:

[Howard Yoder]

Check the return line and filter if the pressure is right i don't know what it is suppose to be but Lavoy will be able to tell you. My 430 was real slow and I put on another return line and it was like a new machine. Good luck

[JD40c]

Might even run some solvent through the suction line (off the tractor) to make sure there isn't a "flapper" or piece of lining that's come loose acting like a valve and blocking the flow.

Possible the pressure relieve is stuck partially open and once the fluid warms up too much leaks past?

[lastchancegarage]

Iherseth,
I read somewhere someone picked up a machine where the previous owner had replaced the hydraulic pump but the machine still suffered with slow hydraulics. After some investigation, the new owner found what he thought was a solid line in the bottom of his reservoir was actually a pickup tube that was plugged solid. He cleaned it up and the machine worked perfectly. Kind of along the lines of JD40c and Howard, check your pickup lines and filter before you swap out pumps. Just a thought. That could be an expensive lesson. Better to blow a few bucks on a filter than big bucks on the pump. Good luck.

Scott

[Lavoy]

You are going to have to run a pressure test to determine if it is the pump. Check it hot, and cold and see what the difference is.
What kind of hyd fluid are you using?
lavoy

[lherseth]

Thanks everybody for the help, hopefully when it warms up here in MN i will check these suggestions out. I have 10W hydro oil in it. I bought a $30 pressure gauge at napa but I have to plumb it in yet. They told me I actually need a flow meter to check the gpm hot and cold instead of a pressure gauge. The flow meter is $125 though so I will check around first and see if I can borrow one. Anybody know if I need a flow meter? Im not sure if it would be the return line or plugged pickup because it always works fine for the first 4 or 5 buckets, its right after the oil gets warm I only can have it half full to get it up to the top. the tank is actually part of the loader, the oil is stored in the loader frame on the right side. Its a a shaped frame with the bottom being wider and bolted to the cross bar by track and the top is up by the hood, thats were the pivot is. Soon as spring comes Ill get a photo of all three crawlers and post them. I have two 420c and a 440I.

[Lavoy]

Don't bother with a flow meter, pressure is your problem, not flow. 1000PSI at 1 GPM will still lift the load, 20GPM at 10PSI will do nothing. Drain your hydraulic system and refill with 30wt hyd oil, that will most likely get you by for a while. It will be a little stiff on startup, but fine when it warms up. IF you want to try it, put in 40wt, which will probably be listed as an AW100. There are also some STP type additives for hydraulic systems. There is one in a white gallon jug, can't think of the name right now. Get it good and warm, and dump a gallon of that in the hud tank. Then work the crawler for a while.
Ultimately you are going to have to rebuild or replace the pump, but any of the above might get you another year out of it.
Lavoy

[lherseth]

Thanks lavoy, Ill give that a try, I wont be trying these ideas till april so Ill let everyone know how it goes.