What would cause just the backhoe functions to barely move at slow idle. The loader function is fine at slow idle. If I throttle up to high the backhoe moves normal speed but digging seems weak. All filters/fluid is new. Seems if hyd pump was weak the loader wouldn’t function fine.
Post your machine serial number for our resident Deere God. Then, do EVERYTHING he says. LOL
Machine serial number is 742565.
Thanks for the fast response too
I read somewhere that there may be a inlet screen on the priority valve under the hood but not sure on that
Full serial number is TO310CA742565
First thing has to be the basics. System pressure checks and pump flow test.
How and where are the pressure checks taken from? Are there ports where they can be taken or something fabricated to test.
There is a port on the loader control valve for testing main system relief pressure. Do you have gauges and know how to use them? As far as flow testing, that takes expensive specialized equipment and you will most likely want to hire someone to flow test the hydraulics.
Here is a pic of the loader valve block. What port is the test port. And by testing this will it show the pressures to only the loader and not the backhoe?? Or is there a test port on backhoe valve block as well
Is below picture correct? I found on another thread here
Will the main system relief pressure give me a idea of hydraulic pump condition
That's it. Both the loader and the backhoe use the same relief. Oil travels through the loader valve before it gets to the backhoe valve. Not necessarily. If the pump is bad enough then it will not be able to produce enough pressure to overcome the relief, but low pressure does not mean a bad pump, yet. Just want to eliminate the basics. On that machine, the loader will operate with what appears to be normalcy with only 1800 psi, while the backhoe does not. The backhoe requires more pressure. There are other things that can cause your weak b/h, but we have to start with the relief pressure setting. Also, you may want to remove and cut open the hydraulic filter to see if it has debris in it.
I did cut open the hydraulic filter when I changed all filters a month ago. Didn’t appear to be any metal flakes present. Reverser screen had a wad of black fibers on it and some metal attached to magnet. Fwd and reverse seems strong. I have a 10000 psi gauge but need to get a hose and the fitting for loader valve port. I did try curling loader bucket to its max for 2-3 seconds as well as the backhoe bucket and it bogged engine down a bit. That should throw it into relief correct ? Is it not supposed to bog engine down. Machine has no tach but im guessing 2-300 rpm
Yes, the engine should "bog" down when holding a function lever against the stop. The machine has what we call an "open center" hydraulic system. Rpm is not important, the relief setting is. Needs to be checked when stalling a loader function @ full throttle, then again when stalling a backhoe function @ full throttle. Preferably with warm oil (140* - 160* F).
Thanks I will get those pressure readings once i get the fittings I need and let you know results.
Ok so I got temp up to 124-128f and pressure reading on loader bkt curl was at 2550 psi and backhoe bkt curl was at 2500 psi. Is this on the low side? I think max is 2800 psi for the main relief valve. Not sure
Spec is 2450 - 2700 psi. Try turning it up to 2700. What is the pressure stalling the B/H Bkt curl at idle? If you can then check all your backhoe function cycle times at full throttle. Post results.
So I will need to turn it in clockwise to increase correct. Maybe 1/2 turn. The backhoe will lift machine off the ground no problem. One thing I did notice yesterday was at not quite full throttle while using backhoe seemed like a whine noise from pump but at full throttle it goes away. Another issue I found is the fan has some play in it like bearing is bad. Not leaking tho. Didn’t like the price of them. Any source on a rebuild kit ? Bearing seal gasket?
If it's just a bearing that you can replace, take it apart and order a new bearing with the numbers off the old one. Don't run it till fixed, you don't want to buy a new radiator.
The bearing comes with a shaft as well from what I see in parts catalog. Probably get the seal and new gaskets as well
Yep, but go a 1/4 turn at a time.