PTO Pump Problems

[atwood]

Well, I finally reached 50 hours on my PT 425 a couple of weeks ago. I had just finished brush hogging a number of trails for a local mountain bike race. The PT worked like a champ. I changed the hydraulic filter before I left for a week on a business trip knowing that I would need to cut the grass when I returned. The filter procedure was relatively painless. When I returned and needed to cut the grass I found that the PTO pump was not working right. When engaged the mower deck blades turned at an unusual slow speed. I hooked up the brush hog and same thing occurred (no normal loud thunk when engaged). I called Terry and he had me remove the solenoid on the block that allows the fluid to pass through from the PTO pump. He thought there must be some debris lodged in the shaft that opens and closes. I wasn’t able to see anything and Terry sent a new solenoid for replacement. When I returned home from a second trip I replaced the solenoid and unfortunately it still didn’t work. On the phone with Terry again I checked both relief valves, made sure that 12 volts were going into the solenoid, actually temporally direct wired from the battery to the solenoid and still no luck. The solenoid seems to be working correctly both visually and audibly. So Terry is sending a new PTO pump. He has been super helpful but is somewhat stumped as this kind of problem he says normally doesn't happen. Question is has anyone else had this kind of problem? Or does anyone have any ideas or suggestions. Coincidence is that this happened right after I changed the filter for the first time and the machine only has 52 hours on it. Any help is appreciated. Thanks.

 

[IH3444]

Remove new filter and fill with oil, reinstall. You may not have drawn a good charge of oil from the sump, to to the filter. It's worth a try.

 

[J_J]

Well, I finally reached 50 hours on my PT 425 a couple of weeks ago. I had just finished brush hogging a number of trails for a local mountain bike race. The PT worked like a champ. I changed the hydraulic filter before I left for a week on a business trip knowing that I would need to cut the grass when I returned. The filter procedure was relatively painless. When I returned and needed to cut the grass I found that the PTO pump was not working right. When engaged the mower deck blades turned at an unusual slow speed. I hooked up the brush hog and same thing occurred (no normal loud thunk when engaged). I called Terry and he had me remove the solenoid on the block that allows the fluid to pass through from the PTO pump. He thought there must be some debris lodged in the shaft that opens and closes. I wasn’t able to see anything and Terry sent a new solenoid for replacement. When I returned home from a second trip I replaced the solenoid and unfortunately it still didn’t work. On the phone with Terry again I checked both relief valves, made sure that 12 volts were going into the solenoid, actually temporally direct wired from the battery to the solenoid and still no luck. The solenoid seems to be working correctly both visually and audibly. So Terry is sending a new PTO pump. He has been super helpful but is somewhat stumped as this kind of problem he says normally doesn't happen. Question is has anyone else had this kind of problem? Or does anyone have any ideas or suggestions. Coincidence is that this happened right after I changed the filter for the first time and the machine only has 52 hours on it. Any help is appreciated. Thanks.

Did you try another implement in the PTO circuit? Did the gas engine ever slow down when you flipped the PTO switch? Do you have a hydraulic gage to check and see if you have the correct pressure in the system.

I would highly recommend that anybody that uses hydraulic type systems, get a hydraulic gage, at least up to 3000 psi or 5000 psi to check out the hydraulic system. This can be done simply with some know how and a few bucks. One gage, and one male part of a quick disconnect, and three female parts of the female disconnects.
First install the 1/4 male part of a quick disconnect to the gage. Then install the female part of the quick disconnect in each of the circuits that you want to monitor, or trouble shoot. One in the steering and lift circuit. One in the PTO circuit. One in the wheel motor circuit. The female part of the quick disconnect should be connected to the tee part of tee fitting. The gage can be left plugged in one of the quick disconnects, and can be moved to any part of the PT for trouble shooting. Use the correct tee for the line that you are installing, and reduce the tee side or gage outlet to 1/4.

 

[atwood]

Did you try another implement in the PTO circuit? Did the gas engine ever slow down when you flipped the PTO switch? Do you have a hydraulic gage to check and see if you have the correct pressure in the system.

I would highly recommend that anybody that uses hydraulic type systems, get a hydraulic gage, at least up to 3000 psi or 5000 psi to check out the hydraulic system. This can be done simply with some know how and a few bucks. One gage, and one male part of a quick disconnect, and three female parts of the female disconnects.
First install the 1/4 male part of a quick disconnect to the gage. Then install the female part of the quick disconnect in each of the circuits that you want to monitor, or trouble shoot. One in the steering and lift circuit. One in the PTO circuit. One in the wheel motor circuit. The female part of the quick disconnect should be connected to the tee part of tee fitting. The gage can be left plugged in one of the quick disconnects, and can be moved to any part of the PT for trouble shooting. Use the correct tee for the line that you are installing, and reduce the tee side or gage outlet to 1/4.

I did try both the mower deck and brush hog with the same results. And I did test the PTO pump with the engine running without implements and no the engine did not bog down at all. By the slow turning of the blades there seems to be some fluid going through just not enough I guess? I don't have a gauge nor am I very experienced with Hydraulics. Since I own this all hydraulic machine, I guess it's time to learn. Where would be a good place to get the gauge and quick connects? Terry suggested that we test the pump but I can't seem to find anyone in my area that has the knowledge or experience with this type of equipment. Since this did happen when I changed the filter maybe I should try as suggested to remove the filter again and refill and bleed. As suggested, can't hurt. Thanks.

 

[DHS]

I had a similar problem two years ago with my PTO solenoid. I believe the ignition switch would heat up and dropped the voltage to the PTO solenoid. Rather than replace the switch, I installed a wire with a fuse from the battery post on the starter to the PTO switch. No more PTO solenoid problems.

You said a measured 12 volts was applied to your solenoid with negative result. So, it is most likely not your switch.

Keep us informed. This problem has several possible causes.

Dale

 

[J_J]

I did try both the mower deck and brush hog with the same results. And I did test the PTO pump with the engine running without implements and no the engine did not bog down at all. By the slow turning of the blades there seems to be some fluid going through just not enough I guess? I don't have a gauge nor am I very experienced with Hydraulics. Since I own this all hydraulic machine, I guess it's time to learn. Where would be a good place to get the gauge and quick connects? Terry suggested that we test the pump but I can't seem to find anyone in my area that has the knowledge or experience with this type of equipment. Since this did happen when I changed the filter maybe I should try as suggested to remove the filter again and refill and bleed. As suggested, can't hurt. Thanks.

The gages can be found at Baileynet.com, or Surpluscenter.com. Baileys has some good stuff. Both are reasonable. A good cd or book on hydraulics would be a good start. Hydraulics is similar to water flow. It's mostly common sense, but keep in mind the dangers of pressurized hydraulics. A Kubota or John Deer place or a rental company should be able to help you trouble shoot your system if it gets that far. The INTERNET in general has a lot of data on hydraulics. On the Internet address line, just type in the exact words you are looking for, and you should get a list to select from. What little bit that I have learned, is from reading and doing. It would be nice to have someone that knows to give a hands on learning situation. A show and tell is what we used to call them.
I would suggest that the valve insides are not moving correctly. What that electric valve is supposed to do is open up one orifice and close off another. It may be partially open. I believe that someone on the forum had a similar problem, and cycled the valve insides a couple of times and it started working. A piece of crud might have gotten in the valve and jammed things up. Hope you get things in order soon. .

 

[BobRip]

Did you purge the air out of the system when you changed the filter. This involves connecting a hose to the pump, running the hose to the hydraulic fill opening and cranking the engine with the spark plug wires disconnected. You should see fluid flow, then air, then more fluid. Don't crank more than 3 to 4 seconds at a time and allow the starter to cool about 15 seconds between cranks. At that point it is purged. Of course (as others have said) you should fill the filter with oil prior to installation. This problem is most likely related to the filter change since that was a significant change between the machine working and not working. The pump might have been damaged if this purging was not done (I don't really know, but running without oil cannot be good).

 

[BobRip]

Did you purge the air out of the system when you changed the filter. This involves connecting a hose to the pump, running the hose to the hydraulic fill opening and cranking the engine with the spark plug wires disconnected. You should see fluid flow, then air, then more fluid. Don't crank more than 3 to 4 seconds at a time and allow the starter to cool about 15 seconds between cranks. At that point it is purged. Of course (as others have said) you should fill the filter with oil prior to installation. This problem is most likely related to the filter change since that was a significant change between the machine working and not working. The pump might have been damaged if this purging was not done (I don't really know, but running without oil cannot be good).

Thinking a little more about this, the hydraulic filter feeds the wheel motor circuit, so I don't see how this can be the problem. You should still purge the air though.

 

[J_J]

Thinking a little more about this, the hydraulic filter feeds the wheel motor circuit, so I don't see how this can be the problem. You should still purge the air though.

Bob, Does your PTO draw fluid through the filter? Is your PTO pump on the back of the tram pump? On my 1445, my PTO pump is on the back of the tram pump, and draws fluid directly from the tank. Bleeding the tram pump and filter has no effect on my PTO pump.

Atwood said he didn't notice any rpm drop on the engine, which tells me that there is not a significant load on the system. One way to test out the pump is to deadhead the pump, meaning that no load is attached. You should only do this for a few seconds. If the pump is working good, it will pull the engines rpms down to almost a stop. The relief valves should cut in and start to chatter. I would guess that the valve is stuck partially open. I wonder why Terry thought that the pump was bad. I would have at least put a gage in th system.

One other way to test the PTO valve, is to get an extra hose and plug in to the output line for the PTO, and run the hose back to the filler opening on the hydraulic tank. Then start the engine, and if fluid comes out of the hose with the switch is off, then it is stuck half open.

 

[BobRip]

My PTO pump draws directly from the tank. I am sorry, but I was originally thinking of the wheel motor pump. My mistake. How a filter change can affect the PTO pump is beyond me. Maybe it is a conincidence or perhaps something lse was disturbed during the change.