DK45 FEL capacity issues?

ksbrdmkr · Nov 3, 2013

I would like to see the torque curve for the DK45. My TN55 3 cyl gets max torque at 1400rpm , so while the engines slows down when pulled it does not stall. The larger hyd pump may pull the engine down more on the DK45 when moving into a heavy lift so the fronts have almost max weight on and lifting the FEL at the same time. I know that stepping fast on the HST in high range from a stop will really pull the engine rpm down.

grm61 · Nov 3, 2013

You never mentioned weather the remote for the rear was on or off?
If on, how is your Hoe plumbed?
The return should be going into the fill hole for the Hyd...there is a kit for this that comes with the hoe that some dealers don't install.

IXLR8 · Nov 4, 2013

grm61 said:
You never mentioned weather the remote for the rear was on or off?
If on, how is your Hoe plumbed?
The return should be going into the fill hole for the Hyd...there is a kit for this that comes with the hoe that some dealers don't install.

My dealer didn't install that kit on my tractor, he had a bunch of kits laying around and gave one to me. As delivered, it is physically impossible to put the new vent tube in place as the tube is made too long and you can't screw the fitting in place. After I cut the tube short enough so I could screw the fitting on... it was lined up facing front and there was not enough room between the tube and the axle to put the rubber vent end on without kinking the tubing rendering it useless. Maybe that is why he, and other dealers, have not been installing the kits.

J_J · Nov 4, 2013

Just an example.

If your pump can pump 10 GPM at 2500 psi, the pump needs about 17 HP.

If this pump is on a 25 HP tractor, it may not ever stall.

If you are stalling and the relief whines, that tells you that you are working at the relief pressure. .

If that pump is in a 17 HP tractor, then it may stall. Keep in mind you are also using some HP for traction, so you may run out of HP. Only way to fix that is more HP. You can adjust the pressure down so as not to stall, but you are also decrease hyd power.

I have three pumps on my Power-Trac, and each pump can go into relief if I am using all three pumps at the max.

Whenever you increase engine rpm's , you are pumping more GPM.

Pressure however is developed because of the resistance to the fluid in the cyl or hyd motors when used.

Relief valves are set to dump the over pressure until the load is removed.

A 3000 psi hyd gage installed inline at the IN port in a tee would be the best place to monitor and trouble shoot the hyd system.

The gage will tell you the operating pressure at any time as to the load on the hyd system and should tell you what is normal and when you are working at relief pressure.

All relief valves should be set the same, unless you want to set a particular relief valve to protect that hyd circuit.

With all valves in neutral, you may see no pressure or some back pressure because of restrictions in fittings, smaller hoses, valve slightly open, etc.

As far as hearing the whine or screeching from the relief valve you may not hear it all the time. That noise is caused by cavitation, and if the fluid does not cavitate, there is no sound.

sdef · Nov 4, 2013

IXLR8 said:
I will be curious to see what your pressure check shows. I am expecting a fairly constant pressure, biggest change will be flow rates but I don't know how you would measure that. I will have to pay closer attention to exactly what I am doing, what the engine is doing, the next time I am moving dirt.

I'll post my results on this thread but it will probably be a couple of weeks before I get the assembly built.

murphy1244 · Nov 4, 2013

IXLR8 said:
My dealer didn't install that kit on my tractor, he had a bunch of kits laying around and gave one to me. As delivered, it is physically impossible to put the new vent tube in place as the tube is made too long and you can't screw the fitting in place. After I cut the tube short enough so I could screw the fitting on... it was lined up facing front and there was not enough room between the tube and the axle to put the rubber vent end on without kinking the tubing rendering it useless. Maybe that is why he, and other dealers, have not been installing the kits.

There was no tube replacement on mine, just a cap replacement.

J_J · Nov 4, 2013

sdef ,

Your tractor has 45 HP, and if the pump can produce 3000 psi at 16.8 GPM's, it will require about 35 HP.

If the pressure setting is about 2500, it will require about 29 HP.

sdef · Nov 4, 2013

Thanks J_J. This will be helpful for my testing. I was wondering which port would be the best place to test.

I have two pumps on my 45 engine HP tractor. Main pump flow= 9.62 GPM with relief at 2560 PSI.
So this ~ matches your 17 HP scenario. In this scenario I should have plenty of power at 1800 - 2000 RPM to go into relief, I would think and not have engine stall. But do not have any engine curves for torque and HP to verify.

There is no relief whine- ever, which I had been expecting to hear. So either I never have any cavitation during relief or never hit relief, which goes along with my original post questions.