L3130 Three Point Hitch Issue

[JRobyn]

What are the chances that the original little suction hose had a SPRING inside of it to keep it from sucking closed, and you omitted it when you replaced it? It might work fine while the hydr fluid was cool, but once it warmed, softening the hose, perhaps the hose is sucking at least partially closed. ??

- Jay

 

[dangier_VA]

Good thought, but there was not a spring in the original hose. In fact, it looked like a washing machine drain hose. Single braid and the ends of the metal pipe were not aligned with the offset being about 1/2 inch with a 1/2 inch gap covered with the hose. The total flow through the 3/4 inch pipe is only part of the suction line flow. It T's into a larger line from the suction filter going to the hydraulic pump.
Thanks,
David

Edit: Please see my post #11. I have 2700 psi available at the loader control at a fast idle. Lines and control valves from loader feed rear piping to hitch. I seem to have plenty of hydraulic flow and pressures up front. Just need to see what the specs are to check out where I am loosing it. Something is hanging up.

 

[Gordon Gould]

Good thought, but there was not a spring in the original hose. In fact, it looked like a washing machine drain hose. Single braid and the ends of the metal pipe were not aligned with the offset being about 1/2 inch with a 1/2 inch gap covered with the hose. The total flow through the 3/4 inch pipe is only part of the suction line flow. It T's into a larger line from the suction filter going to the hydraulic pump.
Thanks,
David

Edit: Please see my post #11. I have 2700 psi available at the loader control at a fast idle. Lines and control valves from loader feed rear piping to hitch. I seem to have plenty of hydraulic flow and pressures up front. Just need to see what the specs are to check out where I am loosing it. Something is hanging up.

You should get approximately the same 2700 psi pressure at any engine speed. The pump should produce the same pressure independent of speed. Higher RPM's increases the flow but not the pressure if things are normal. You didn't really say that you have less pressure at lower RPM but I thought I should mention this.

 

[Leejohn]

The control valve under the seat, where remote valve hookup there are 2 safetyvalves. The spring might of broke in one, they are just a poppet valve. One other thing that it might be is a o ring for the 3pt control valve is leaking by. There also is a plug on top of the control valve that you might be able check the psi to the 3pt valve. When you get your manual it should tell you if that plug is for checking psi. Look on line for a parts manual and look at the control valve.

 

[dangier_VA]

You should get approximately the same 2700 psi pressure at any engine speed. The pump should produce the same pressure independent of speed. Higher RPM's increases the flow but not the pressure if things are normal. You didn't really say that you have less pressure at lower RPM but I thought I should mention this.

Makes sense. I was just trying to give out as much information as I could. Throttle just happened to be at fast idle while trying to diagnose hitch issue.

 

[dangier_VA]

The control valve under the seat, where remote valve hookup there are 2 safetyvalves. The spring might of broke in one, they are just a poppet valve. One other thing that it might be is a o ring for the 3pt control valve is leaking by. There also is a plug on top of the control valve that you might be able check the psi to the 3pt valve. When you get your manual it should tell you if that plug is for checking psi. Look on line for a parts manual and look at the control valve.

I do have the Messick's parts pdf breakdown and there are a lot of plugs on the 3 pt control valve. Don't want to lose some small critical part at this point. Was going to put the gauge on the control valve output to the hitch, but I already know that the pressure is not there as it does not work like it should. Trying to think of everything I did during this service where I think the problem started. I did take the front loader off the tractor as I needed to do the overdue engine valves check/adjustments. Just undid the quick disconnects and put back on reinstall. Disconnects are color coded so they went back in the same place. Have had the front loader off several times before. Wondering if this is just a coincidence or what!!
David

 

[dangier_VA]

Just wondering, in your posts you say "UDT". Do you actually use UDT or SUDT? The manual specifies SUDT, and even though it's really expensive, I've never dared use anything else. Actually, I guess it's mostly for the HST transmission, and wouldn't matter for the 3ph, and you say the tractor travels okay.

My kubota manual specifies UDT or SUDT for the trans/hydraulic fluid.
David

 

[jimainiac]

If you've been using UDT fluid right along with satisfactory results so far, I guess this is a moot point, but my operator's manual, which covers the whole Grand L model line from 3130 to 5030 does in fact at least "recommend" SUDT. On page 84, under Changing transmission Fluid, step 3 - "Fill with the new KUBOTA SUPER UDT fluid up to the upper notch on the dipstick. (See "LUBRICANTS" in Maintenance section).
On page 67 of the Maintenance section under Transmission case it does indeed say KUBOTA UDT or SUPER UDT fluid*. But one of the notes at the bottom of the page says "We recommend the use of KUBOTA SUPER UDT fluid for optimum protection and performance. (Consult your local KUBOTA Dealer for further detail.) Do not mix different brands or grades."
I took that to mean that they really want SUDT to be used. If I had to guess, I'd say it's probably most important for cold weather operation, such as we encounter up here in Northern New England.
Also, you sound pretty sure that the replacement of the short piece of hose isn't the problem, but it is one of the only things that was changed.
If you haven't had any luck so far, it may be time to put in a call for the detective most extraordinaire, Hercule Poirot, to use "the little gray cells".

 

[jimainiac]

I don't know about anybody else, but I'm wondering how you're making out with your 3ph problem. I hope you've gotten it fixed, but if you haven't, I thought of something that might make your 3ph seem to act differently, and appear to be weaker. If you had taken your top link off for better access when you did the fluid change, and the top link was put back in a different one of the three mounting holes, it may affect the ability to raise an attachment. It changes the geometry of the assembly, I think.

 

[dangier_VA]

I don't know about anybody else, but I'm wondering how you're making out with your 3ph problem. I hope you've gotten it fixed, but if you haven't, I thought of something that might make your 3ph seem to act differently, and appear to be weaker. If you had taken your top link off for better access when you did the fluid change, and the top link was put back in a different one of the three mounting holes, it may affect the ability to raise an attachment. It changes the geometry of the assembly, I think.

Jim,
Appreciate the follow-up. Have shop manual on order and waiting for that. Want to check the hydraulic input pressure for the rear hitch. With the many plugs and taps on the top of the transmission housing, I don't want to pull the wrong plug out and have springs, etc., fly and get lost.
I didn't change anything on the tractor when servicing the hydrofluid (other than fluid and filters). Did notice a connector broken off the side of the hydro trans (right side, about halfway back). Don't recall seeing that broken, but who knows. Wires just hanging for now. As soon as I get the manual, I should be able to start somewhere and find out what is happening.
Thanks,
David