DK45 FEL capacity issues?

[ksbrdmkr]

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]

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]

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]

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]

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]

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]

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]

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.

 

[k0ua]

Here is the torque curve for the EX-45.. the international version of the DK45 as sold in Australia. I would assume the engine is the same as the DK.




James K0UA

 

[IXLR8]

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

My cap was the vent, replacing it with the return line "seals" up the system, where is the vent now for your tractor?

 

[IXLR8]

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.

Back to your original question, and thinking about it some more. I don't think I have ever heard the 'relief whine' when my loader or BH hit it's limit, on either my CK30 or my DK40. The only thing I hear is a change in tone in the engine like it is working harder and it might drop a few rpm's. I have heard the HST whine on the CK30 when it was working harder than it should have been, I just seem to stall the DK.
J_J has me thinking that maybe the reason I am stalling the DK is the higher flows for both pumps may be conspiring to require more HP when digging and moving at the same time. I need to look into this further.
k0ua- thanks for the power curves. I am going to assume that the curves for the DK40 is basically the same, just lower on the graph.

 

[sdef]

Thanks again to JJ and James K. From JJ's comments and James K.'s torque curve chart, assuming it is the same engine, 1800 - 2000 RPMs should work out well and I would not expect to see the things I am. I guess the pressure testing will confirm it all.

Great information folks.

 

[k0ua]

I posted the DK40 curve, for a minute, but it has to be an error in my manual. as it is the same as the DK35. so I deleted the post. Sorry

 

[murphy1244]

My cap was the vent, replacing it with the return line "seals" up the system, where is the vent now for your tractor?

They put in a curly style vent on the other side of the Trans. My fill cap was changed for a fitting then a 90% fitting them a female Pioneer coupler. We does your Dealer not want to put these kits on?

 

[IXLR8]

They put in a curly style vent on the other side of the Trans. My fill cap was changed for a fitting then a 90% fitting them a female Pioneer coupler. We does your Dealer not want to put these kits on?

The curly style vent is the issue. Mine came as 2 pieces. A fitting with a tube that was bent at a 90deg that screwed into the other side of the trans. Then a curly rubber hose fit on the tube. The tube was too long to allow the fitting to screw into the side of the trans. After I shortened the tube, about 1", to be able to screw fitting into the trans, when tightened the tube faced forward towards the axle, it should have been facing up. When the curly rubber hose was put in place it was up against the axle and it was kinked, closing off the air flow. The instructions indicate that the tube and the fitting are separate making it possible to position the tube at the correct angle for the curly rubber hose to fit/work properly. But in reality the tube and the fitting are now welded together and what direction the tube ends up pointing is a crap shoot. If you want I will take picture when I get home this weekend.
I suspect the dealer is not installing them was for several reasons; he didn't seem to know what they were for, and they are not made correctly and take some modifying to work. He has been in the business for over 30 years and doesn't remember ever installing this kit and doesn't see any reason to.

 

[Coyote machine]

The curly style vent is the issue. Mine came as 2 pieces. A fitting with a tube that was bent at a 90deg that screwed into the other side of the trans. Then a curly rubber hose fit on the tube. The tube was too long to allow the fitting to screw into the side of the trans. After I shortened the tube, about 1", to be able to screw fitting into the trans, when tightened the tube faced forward towards the axle, it should have been facing up. When the curly rubber hose was put in place it was up against the axle and it was kinked, closing off the air flow. The instructions indicate that the tube and the fitting are separate making it possible to position the tube at the correct angle for the curly rubber hose to fit/work properly. But in reality the tube and the fitting are now welded together and what direction the tube ends up pointing is a crap shoot. If you want I will take picture when I get home this weekend.
I suspect the dealer is not installing them was for several reasons; he didn't seem to know what they were for, and they are not made correctly and take some modifying to work. He has been in the business for over 30 years and doesn't remember ever installing this kit and doesn't see any reason to.

Your dealer may have been in the business forever, but the pic below, (borrowed from someone else's setup at: just-bought-dk45se) shows the proper kit and 'new' type vent at the left side of the trans just under the 3PH top link pin. The old red cap is replaced with the screw in male and attached female QD to connect the return line from the backhoe to the fill port for the transmission. There IS a need for this kit. It increases flow to the hoe and keeps the heat down by allowing for more flow and therefore less strain on the hydro pump and associated parts. AND it allows for best performance from the attached hoe. You are the only person I'm aware of that says the new vent portion doesn't fit the application.

http://www.tractorbynet.com/forums/...67d1381530100-just-bought-dk45se-img_1366.jpg

 

[rjwerth]

You are the only person I'm aware of that says the new vent portion doesn't fit the application.

http://www.tractorbynet.com/forums/...67d1381530100-just-bought-dk45se-img_1366.jpg

You missed my experience with the kit then. I had the same problem and had to take a Dremel to the vent to get it to fit... (Sorry for continuing the hijack).

 

[gunmonkeyintl]

I had to modify the replacement vent in the same way described by others here. I hacksawed to a usable length and deburred the opening to avoid filings going into the reservoir. Otherwise, it fit fine.

 

[grm61]

Had to shorten my tube as well...Its just a vent. it does not have to be ball busting tight, if it is to loose where it fits correctly, you could wrap the fitting with teflon tape to "firm it up" where it needs to ride after tightening.

If you go this route, wrap the tape very tightly so pieces of it don't wind up in you Hydro system.

It is said with the return routed into the other remote port, there is internal backpressure which causes heat and reduced hydro performance.

Why would they go to the extra expense to supply the kit if there was no reason?

Having said that my point is if your hoe is on and the remote is turned on, you are circulating fluid through there.

If it is restricted, that would put more stress on the rest of the hyd system.

Your talking about making it "right" I would address this known issue.

 

[sdef]

Sorry for continuing the hijack).

No worries. I have my information. Continue