RTV X1140 No Movement or Drive, HST Problem

[Magfarmer]

Kubota
2017 RTV-X1140
1074hrs / 6798 miles
I have WSM RTV-X1140 (Rev. Date 08/21) (PN 9Y111-09968)

History:
Purchased at auction, was used by a construction company.

Maintenance:
Generally, looks to have been good, all grease fittings I looked at were freshly greased. Oil & hydraulic filters had Hours & Date written on them and were close to the 1070hrs on the Operator screen.

Condition at purchase:
The motor would start and run.
The unit would not move forward or reverse.
The transmission level showed good on the dip stick.
But also I found that there was almost no hydraulic fluid in the tank under the seat.
During the filter change I found that the big filter (Suction?) was loose, and that would explain why it leaked every time the engine was started.

Current Status:

1. Drained the hydraulic tank and replaced the two Hydraulic filters with new Kubota filters. Refilled the tank. Yes UDT2.
2. Jacked the rear end off the ground. Placed in 2wd and started the engine and allowed the oil to circulate in neutral for about 10 or 15 minutes. Could see it circulating in the tank under the seat.
3. I then put it in high and slowly depressed the peddle, until I was “Full Throttle”. The rear tires started to turn, and it would get to about 13 mph. reverse to 9 mph. I did this a couple times.
4. Changed the filters again. I cut the filters open to check for debris and found nothing. Very clean with no metal fines or anything.
5. Replaced filters and topped off UDT2. Drive turns rear wheels when lifted with jack.
6. No change in drive, RTV will not move when on the ground and tried in forward or reverse.
7. Hydraulics for the steering and Bed work fine.
8. I have looked at the Engine Cable, and there is slack or droop in the cable, and the HST linkage will move some before the throttle lever even starts to move. The throttle lever at full throttle, has about 1/8” from lever to throttle stop screw that is wire tied fuel control valve, after the foot peddle is against the stop. I attached a couple pictures.

So, I have read as many postings as possible about and RTV not moving, and I have reviewed the WSM on all testing of HST. Not the best step by step guild, so I may ask for some clarity as I come to that point. I have purchased a Laser Tach and a Hydraulic Pressure Test kit off Amazon.
Laser Tach - https://www.amazon.com/dp/B0765XP9LS?psc=1&ref=ppx_yo2ov_dt_b_product_details
Test Kit - https://www.amazon.com/dp/B07HQ3CZ1B?psc=1&ref=ppx_yo2ov_dt_b_product_details

Here is my plan, I will be detailed, and as I am an engineer, it is a habit.
I hope the experts on here can give me direction if they see something I am not going to do correctly.

The plan:

1. Verify the engine RPM with the laser Tach. I think I can get a piece of the reflective tape to stick to a flat on the crank nut. I don’t plan to remove all the plastic covers, and I can see the nut from above. If there is a better location, let me know.
2. Check Charge Relief Pressure (Page 2-S6)
   1. Engine Speed - 1400RPM
   2. Oil Temp – 120°
   3. Document Results (Spec: 63 to 120 psi)
   4. If I see no Low pressure here, I may not go forward and just know I must do a full teardown and evaluation.

This is where the “Charge Pump” come into play. If the pressure is low, is it worth trying to replace it and see what happens?
Or does it make since to take it down and look at the brass plates, pump, and motor?
If in specification, I will go forward with the following test, and evaluate the data.

1. Checking High Pressure Relief Valve Pressure (Traveling Side) (Page 2-S7)
   1. Apply Parking Brake
   2. Place in “H” Gear
   3. Engine Speed - Maximum while transmission stalling.
   4. Oil Temp – 120°
   5. Document Results (Spec: 3560 to 3980 psi)
2. Checking High Pressure Relief Valve Pressure (Dynamic Brake) (Page 2-S8)
   1. Apply Parking Brake
   2. Remove the neutral rod (HST control rod) (3) from the HST control lever (4).
   3. Place in “H” Gear
   4. Engine Speed - Maximum while transmission stalling.
   5. Oil Temp – 120°
   6. Document Results (Spec: 3560 to 3980 psi)

OK, what do you think of my plan?
Have I missed something?
I look forward to everyone's input.
Thanks and have a great weekend.

 

[Armyaviatr]

aurthuritis is truly the Guru when it comes to these transmissions, with that being said all I can offer is some simple things to look for. When you had the suction screen out of the Hydraulic tank did you make sure that fluid would flow through the screen? Another issue to check for is to make sure the rubber hoses coming to and from the tank don't collapse when the machine is running. And finally, the filters are in the right place, don't trust the colors or that the part numbers are the same as you took off, verify with a parts diagram or the WSM . These are the simple things that will cause you headaches.​

 

[Magfarmer]

I do look forward to his input. I also just printed his instructions on setting the peddle travel, throttle position cable and speed rod.
I have not verified if the hoses are collapsing but when running I see the oil circulating very well, when looking inside the tank under the seat. That is on my list to verify. On this model you can't switch the filters, as one has a much bigger thread fitting.

 

[Magfarmer]

Today's Data:
Checked the Engine Idle, and the RPM was 1388.
From the WSM, Page 2-S12 it looks like Engine idle speed is 1400 to 1500 RPM.
I saw there is a stop on the throttle lever for idle, so it will need to be adjusted once I have everything else done.
I don't see being 12rpm off min as a major issue at this point, when the peddle travel, throttle position cable and speed rod mechanism will need to be adjusted once it is moving.

Second,
I was about to check the Charge Pressure and I hit a snag.
The kit has the fitting to connect to the Charge Pressure port, but it does not have a pressure gage that will measure the 63psi to 120psi Charge Pressure. The lowest rated gauge is 3500 psi at 100 psi graduations. The gauges in this kit are all BSPP threads, So I have to find a 0-200 psi gage with BSPP threads or an adaptor to go from the hose that requires a BSPP thread to a 0-200 gauge that has an NPT thread.
Looks like I will make a trip to the Parker Store.
FYI, the Test Port Thread specifications are: (I never saw it actually documented in the treads, so here it is...)
Charge Pressure: G1/4 BSPP British Standard Pipe Parallel w/O-Ring Seal.
High Pressure: G3/8 BSPP British Standard Pipe Parallel w/O-Ring Seal

If anyone has any suggestions, let me know.
Tomorrow is another day.. Have a good one..

 

[Magfarmer]

Today's Data:
Checked the Engine Idle, and the RPM was 1388.
From the WSM, Page 2-S12 it looks like Engine idle speed is 1400 to 1500 RPM.
I saw there is a stop on the throttle lever for idle, so it will need to be adjusted once I have everything else done.
I don't see being 12rpm off min as a major issue at this point, when the peddle travel, throttle position cable and speed rod mechanism will need to be adjusted once it is moving.

Second,
I was about to check the Charge Pressure and I hit a snag.
The kit has the fitting to connect to the Charge Pressure port, but it does not have a pressure gage that will measure the 63psi to 120psi Charge Pressure. The lowest rated gauge is 3500 psi at 100 psi graduations. The gauges in this kit are all BSPP threads, So I have to find a 0-200 psi gage with BSPP threads or an adaptor to go from the hose that requires a BSPP thread to a 0-200 gauge that has an NPT thread.
Looks like I will make a trip to the Parker Store.
FYI, the Test Port Thread specifications are: (I never saw it actually documented in the treads, so here it is...)
Charge Pressure: G1/4 BSPP British Standard Pipe Parallel w/O-Ring Seal.
High Pressure: G3/8 BSPP British Standard Pipe Parallel w/O-Ring Seal

If anyone has any suggestions, let me know.
Tomorrow is another day.. Have a good one..

Ended up buying a separate hose with the correct fittings on each end. $50

 

[Magfarmer]

Just checked the charge pressure. Right at 45 psi. Unless anyone has an ideal of something besides wear on the pump. I guess I will start the tear down to evaluate the rest of the unit...

 

[aurthuritis]

howdy--- very good detailed info. things i picked up from reading. high idle adjustment is low very low should be 3600 rpm when the fuel pump control lever is against the upper limit screw. i suspect your machine is grossly out of adjustment so go through the peddle hst adjustment and get the relationships all propper first and then check pressures. low idle isn't as critical unless unit is shaking

 

[Magfarmer]

Thanks, I will check all the adjustments soon. I am traveling this week for work. Got to pay the bills.
One question, at idle I am at 1388 rpm, should I not be better than 45psi? Are there any relief valves that could be affecting that?

 

[aurthuritis]

the charge pressure might increase some if you adjust the idle rpm up to spec. the hst speed lever could be advanced and cause a little pressure loss. it is just a good idea to fix all the simple things first before getting inside the transmission. it is possible that air was getting into the system or maybe the previous owner wasn't the best on maintenance??? got to get the charge pressure in spec first and then move from there.

 

[Magfarmer]

Update 11/13/22:
I pulled the HST and found that the Pump was wore out. Piston bits got wedged in the pump swash plate and cradle bearings. I still need to pull and check all the pressure relief valves down to the base and I see lots of Brake Clean in my future. I guess it is time to start pulling a parts list together. Can someone say Big Buck/Lots of Whammies $$$$$$$$$

 

[aurthuritis]

wow! catastrophic failure. have you priced a new hst from kubota? i don't know but i think it might be cheaper than rebuild that one? and you would get a 1 year warranty also i think?

 

[Armyaviatr]

Messics shows $6346.81 for part number K7731-14043. Coleman equipment out of Kansas shows $5,814.64, and Stoens.com shows $3845.00 with a $1200 core charge. Based on the weight it would almost certainly ship freight. Mine came strapped to a pallet. I would recommend using your local dealer if you decide on a new unit. My dealer only charges me shipping if I need it ASAP. Typically if my dealer orders it, it only takes one or two days longer than Messics.

 

[bczoom]

If you're considering a new unit, check with the sales department to get a price on it as "whole goods".
It's been years but I remember there were several items you could buy from the sales department cheaper than the parts department.

 

[Magfarmer]

I believe that I did not do too much damage even given the look of the pump.
The HST Motor and thrust bearing showed no damage, and the surface on the thrust plate was very smooth.
The HST pump was the main failure component, and I am sure that is because it spins at the rpm of the motor.
The FOD (Foreign Object Debris) from the pump did embed itself in the the pump swash bearing.
Well I am a gambler... So I am going to replace the Pump, Pump Thrust Bearing, I may clean up or replace the pump swash plate assy, and pump thrust plate. O-rings and all and see what it does. I ordered $1400 in parts from Messick's. We will see if my bet pays off.
I fully understand the mechanics and finishes of the system. We will see if discretion would have saved me $1400 and I bought a $6k or 3k unit.
Bets anyone...lol

 

[Armyaviatr]

I believe that I did not do too much damage even given the look of the pump.
The HST Motor and thrust bearing showed no damage, and the surface on the thrust plate was very smooth.
The HST pump was the main failure component, and I am sure that is because it spins at the rpm of the motor.
The FOD (Foreign Object Debris) from the pump did embed itself in the the pump swash bearing.
Well I am a gambler... So I am going to replace the Pump, Pump Thrust Bearing, I may clean up or replace the pump swash plate assy, and pump thrust plate. O-rings and all and see what it does. I ordered $1400 in parts from Messick's. We will see if my bet pays off.
I fully understand the mechanics and finishes of the system. We will see if discretion would have saved me $1400 and I bought a $6k or 3k unit.
Bets anyone...lol

Good luck.

 

[aurthuritis]

I believe that I did not do too much damage even given the look of the pump.
The HST Motor and thrust bearing showed no damage, and the surface on the thrust plate was very smooth.
The HST pump was the main failure component, and I am sure that is because it spins at the rpm of the motor.
The FOD (Foreign Object Debris) from the pump did embed itself in the the pump swash bearing.
Well I am a gambler... So I am going to replace the Pump, Pump Thrust Bearing, I may clean up or replace the pump swash plate assy, and pump thrust plate. O-rings and all and see what it does. I ordered $1400 in parts from Messick's. We will see if my bet pays off.
I fully understand the mechanics and finishes of the system. We will see if discretion would have saved me $1400 and I bought a $6k or 3k unit.
Bets anyone...lol

you have had eyes on the damage and can fingernail the finishes on the swash etc. it is your call. please respond with results so we can learn ??? Thanks for posting this.

 

[Magfarmer]

you have had eyes on the damage and can fingernail the finishes on the swash etc. it is your call. please respond with results so we can learn ??? Thanks for posting this.

Yes sir, I have been an engineer involved in machining for 30yrs, so I have a calibrated fingernail...lol I can also take it to the lab and check finish on a profilometer. I used a loop to look for any heat cracking on the motor thrust bearing. I hardest thing will be making sure I wash all the FOD out and make sure all the relief valves are clean. One question, how much oil should I fill the case with before starting it? I think I can fill from the rear plug. I definitely will try and document everything and let ye'all know how I do. Thanks for the input.

 

[aurthuritis]

just fill to the normal amount through the fill plug dipstick on top of the transmission. then check and adjust afterward. sounds like you have this under control. thanks for sharing.

 

[Magfarmer]

Sorry for the log absence, but work has had me traveling a lot and just been busy. Anyway, I was able to assemble the HST unit using only the most needed parts in order to keep the rebuild to a minimum. I will post my parts list after all done. I I have installed it on the Transmission, filled the oil and got it all running. To my own amazement, it ran, and had only small leaks where the Return and Suction bolt to the Port Block and Cover. I see now from the parts list that these require "2" O-rings each, and I know I only have one in place. So I have ordered new ones to go there and will replace them when I get them. during the check of all the system, I found the oil to be Foaming a lot. I looked this up, and it is called Entrained Air Contamination. defined as clusters of air bubbles that aren’t just on the surface of the hydraulic fluid but are actually dispersed throughout, it is referred to as entrained air and can cause some serious issues for your hydraulic system in general and your final drives in particular. One of the most notorious sources for entrained air is pump inlets, but it can also enter the system through low reservoir fluid levels and leaks in suction lines.

I started looking over my suction line and found cracks in the suction hose near the hose clamp at the top... I will attach a picture. I am guessing it is sucking air in and causing my problem. I am looking at ordering them.. BTW the Suction hose from Messick's is $37, and the return is $45. Anyone have a off the shelf Hydraulic hose, Fuel Hose option that is less expensive and still does the job correctly? I did take it for a short test drive, and I got to 23mph and it ran fine.... With the air in the oil, I did not want to run it long.

Again , I will post a couple pcs of the parts I replaced and the total rebuild once I solve the foaming Oil and couple leaks. Other than that I will see if it holds up. I do appreciate al the help and suggestions I got at the start. Later my friends...

 

[pioneer]

Sorry for the log absence, but work has had me traveling a lot and just been busy. Anyway, I was able to assemble the HST unit using only the most needed parts in order to keep the rebuild to a minimum. I will post my parts list after all done. I I have installed it on the Transmission, filled the oil and got it all running. To my own amazement, it ran, and had only small leaks where the Return and Suction bolt to the Port Block and Cover. I see now from the parts list that these require "2" O-rings each, and I know I only have one in place. So I have ordered new ones to go there and will replace them when I get them. during the check of all the system, I found the oil to be Foaming a lot. I looked this up, and it is called Entrained Air Contamination. defined as clusters of air bubbles that aren’t just on the surface of the hydraulic fluid but are actually dispersed throughout, it is referred to as entrained air and can cause some serious issues for your hydraulic system in general and your final drives in particular. One of the most notorious sources for entrained air is pump inlets, but it can also enter the system through low reservoir fluid levels and leaks in suction lines.



I started looking over my suction line and found cracks in the suction hose near the hose clamp at the top... I will attach a picture. I am guessing it is sucking air in and causing my problem. I am looking at ordering them.. BTW the Suction hose from Messick's is $37, and the return is $45. Anyone have a off the shelf Hydraulic hose, Fuel Hose option that is less expensive and still does the job correctly? I did take it for a short test drive, and I got to 23mph and it ran fine.... With the air in the oil, I did not want to run it long.



Again , I will post a couple pcs of the parts I replaced and the total rebuild once I solve the foaming Oil and couple leaks. Other than that I will see if it holds up. I do appreciate al the help and suggestions I got at the start. Later my frienNice workds...