2006 RTV900 dump bed not working

Hello,

I've been searching through the forum for a similar issue to mine without luck thus far, but I have learned a lot about these machines and feel a lot better after reading through this forum. I recently bought a 2006 rtv 900 from a friend and knew the dump bed was not working. I didn't think it was a big deal because I didn't know if I'd be using the bed for dumping anyway. Boy was I wrong!!! When raising or lowering the lever there is no sound or load on the engine whatsoever. Its like no power is getting to the pump at all. I've checked the connections and everything seems to be in the right spot. Is there a fuse for the dump bed alone? The transmission seems to be fine and the fluid levels check out okay too.

Any ideas?

Welcome to the forum and congrats on your new-to-you RTV.

When you checked fluid levels, did you check the reservoir for the dump?

Are you using OEM filters and UDT or Super UDT fluid? When was the last time they were changed? There's 2 filters for the hyd system and they're different colors. Can you tell us which color filter is at each location?

When the engine is off, how hard is it to manually lift the bed? There's a hydraulic bypass on your dump control. Push it all the way forward (you may have to slam it kind of hard). It should lock in that forward position. When in that position, is the bed easier to lift or the same?

There's hydraulic ports at the rear of your machine. Don't know which model RTV you have but is there 2 ports or 4? When looking from the back of your machine, they're just to the right of the large black reservoir (which is the fluid reservoir for your dump bed). The dump bed should be connected to the 2 innermost if you have 4 ports.

Hi and welcome to the greatest forum around jdg2259.
I'd check that the hydraulic couplings are still connected properly at the rear of the machine too. I think they are color coded white and yellow with caps dangling. Also check that the control lever handle is connected still under the plastic shroud. I 'll check mine this evening and report back. collie

bczoom and bordercollie, thank you for the kind words and for taking the time to read my post...

According to the guy I bought this machine from he only used Kubota filters and fluids. I have a call into him to see when the last time was he changed the filters and fluids. If I remember correctly I believe he said there were about 25-30 hours put on it since the last maintenance (don't hold me to that though). There is an orange filter directly under the hydraulic res (more to the center of the buggy), and a yellow filter which is closer to the right rear tire (if looking at it from behind).

Since learning on this site about the hydraulic bypass it is seemingly easier to raise the bed while the lever is in the "all the way down" position.

I only have 2 ports and the white is on top of the yellow and the hoses appear to be in the correct spots.

Thank you both again for your time and for reading this post.

Welcome aboard.....LOTS of us read your posts, but most of us don't just rattle off some nonsense to get their words in print.
You don't have a fuse or any electrical connections to the bed. It's all hydraulic and a pretty simple direct mechanism. For me, this is a head scratcher. My 05 has 2 hydro hoses that are both connected and I suppose they go to the bed. Under the rear tank reservoir is a white filter with a yellow one over by the tire. I remember a few years ago that there was a filter COLOR change for the hydraulics so that might explain the different color in yours............

If it was me, I would change the connections for the hoses and see if something happens. You aren't going to hurt anything; but be sure to just put them back to their original positions.

Well, doesn't sound like the previous owner knew why the bed was raising either??

Not knowing his mechanical prowess, I'd start by making sure the hydraulic tank level is correct.

I wouldn't start buying filters and oil for a change until I had resolved the not working issue.

Instinct is saying to me that if questioned diligently the previous owner might admit the be quit when he last changed the oil/filters? Might want to verify that?

Next thing I would check is if moving the lever actually moves the valve actuator? It's cable operated and might be something so simple as it's not functioning??

Not hearing any change in noise or load on the engine when the handle is moved is actually a good sign.

It's correct that the bed is easier to lift by hand if the lever is forward in the float position. Actually, if everything is operating correctly it should be extremely difficult to raise the bed by hand if the lever is in the neutral position. Sometimes I'll bump the lever toward the lower position just to load the cylinder and then carry substantial weight on the bed and lowered tailgate. The lift cylinder will hold the bed in place and not allow it to tilt.

If we keep throwing ideas back and forth we'll resolve this. I'm a KISS principle guy and would start with the most simple things. Such as does it have adequate oil in the reservoir?

Friends, My hydraulic reservoir at the rear of the machine , is independent of the transmission and it's filters. I change fluid and filters on the transmission( 2011 model 900) -the side tan one and the formally orange- now white one in the rear then fill at the transmission's top . The hydraulic reservoir is a separate deal for the hydraulics- that's the way I have always understood it. The filters should not have anything to do with the dump cylinder nor its reservoir. collie

edit: the white coupling is on top and the yellow below on my rtv also.

Yes, Border Collie. It's seldom I drain that tank in the back and change that fluid. It truly has nothing to do with the trans and those hydros; but it's only job is the dump. I figure that if the only work that it sees is the dump then there isn't a lot of heavy work on that one cylinder of the bed. Vs a tractor that has only one pump but the HST trans, the 3ph, and bucket all combine for a lot of work/dirt.............

I do remember back in the early days that some tanks were actually melting from the heat of the fluid. The up/down lever would be out of adjustment and the fluid would get hot from the pump always being engaged and melt a hole in the tank...........

Yes, it does sound like the lever is not hooked up and that would be the place to begin as one should hear a noise or change in engine level when one engages the lever at all

Yes, I agree. If it were me, I'd look behind that plastic shroud and see about the lever and then follow it to the pump - making sure all is moving.. it could possibly.. maybe maybe.. be a bad or loose cable... now that would be a simple fix.
Years ago, I put a hydraulic cooler on my RTV to keep the reservoir much cooler when I was using the weed wiper. That is the only time I added oil to the reservoir- that and when I added the extra hose length for the weed wiper. There is a thread on here about that too but a different subject so I won't link to it. collie

Loosen one of the hoses on the cylinder and engage lever to see if your even getting fluid to lift cylinder.

also if you or whoever uses crappy ole hydraulic fluid that tends to foam it will be impossible for the pump to build pressure. What's the hydraulic reservoir look like? Good oil? Milky? Foamy?

Engaging the hydraulic dump lever either up or down while the engine is idling will have a noticeable effect on the engine and is easily noticed. My vote goes with the linkage from the lever to the back ...assuming the reservoir tank fluid level is correct and the pump is functional.

thank you all for the replies... a ton of great info. So last night I ended up hearing from the guy a bought it from (friend of a friend now - I realized where I stand) and found out he used the hydraulics to run a log splitter and said one day it got hot and fluid started leaking from the res box. Said he patched the box and didn't really use it anymore for log splitting and realized the dump bed wasn't working and never really messed with it again (after hearing this I realized he wasn't a friend of mine; this would have been good to know the day I was buying it - I still would have bought it). I unbolted the box last night and found his handy work on the back side of the res. box. Maybe a golfball sized hole covered over with what appears to be melted plastic - I'm guessing he used a plastic welding kit or something like that, but the plastic he used is really weak - maybe same consistency as a Zepherhills 12oz water bottle (I ordered a new res box and should have it in a few days).

I'm not sure if that's what is causing the dump bed to not work but I wanted to pass that info along. The fluid in the box didn't look foamy or milky either; it actually looks really clean believe it or not. I'm also going to follow the cable and see if it is doing what it should be doing, and then I'll remove a line and see if fluid is moving as well. Might wait until I get the new box on there first though.

Thank you all again for the great info. I thought I was going to be in over my head buying a used rtv 900 but this forum makes me feel a lot better about it. There is a ton of great info on here that I have already taken advantage of (raising the air intake, crazy radiator location and keeping it cleaned out, temp gauge makes it appear engine is way hot, etc.).

Would the patch job on the res. box prevent the hydraulic system from building enough pressure even though fluid isn't spraying out anywhere?

Sure hope it's the linkage to the pump...I don't like the fact that a hole got melted due to a log splitter being attached. Losing all the fluid hopefully didn't trash the pump. Good luck!

Hi and welcome to our forums. Lots of great help here. Kudos to all the members who will jump in with advise whenever they can. Makes this place so awesome.

I've never used my hydraulics for any auxiliary equipment but I have to wonder if vapor lock could be causing your no dump issue.

In 2012 I bought an 06 RTV 900 w/ 635 hours on it. It has served me well. The one thing I would do if I were you is change out the fluids and filters using Kubota Super UDT and Kubota filters. Then you know the right fluid is in there. We've heard of weird and low power issues when folks go with off brand hydro fluids and other filters.

Good luck and please keep us posted.

For the fluid looking clear or milky, was it after sitting or after you tried running the bed up and down? (It'll return to clear after sitting).

I'm not strong in hydraulics but just walked out to my RTV and if in the same situation, tell me if this is a viable test.

Using these as a given: the tank is bad, the fluid should be replaced when replacing the tank.
Check all linkages as previously discussed.

To see if the pump is any good:
Get a clean 5-gallon bucket. Catch and possibly reuse the existing fluid for further tests.
At the quick-disconnects, don't use the quick disconnect but unscrew whichever (I forgot to look to see if it was the top or bottom) is the one that comes out of the pump. Have the bucket catch the fluid.
Cycle the dump bed lift from the operator position and see if fluid flows to the bucket. Do it only briefly so you don't suck the tank dry.

I don't know what the flow should be but any flow should theoretically imply it can move the bed. No flow = bad pump or clogged pump (sucked in melted plastic?)

Theres still a slight chance the linkage is messed up. Very slight. If you push the lever forward and it detents into the float position, the linkage is okay.

What I'm reading is it hasn't worked since the meltdown. Bummer. That would indicate the pump isn't working.

Standing by for response in regards to linkage.

Kanook said:

Sure hope it's the linkage to the pump...I don't like the fact that a hole got melted due to a log splitter being attached. Losing all the fluid hopefully didn't trash the pump. Good luck!

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Its hard to believe the pump would be damaged.It is a stupid simple system.Its a gear driven pump and im not sure if there are any seals in it or not.I looked into these when i was adding options for my machine which did not have the dump on it.If it were me id look into the valve switching body.I believe if memory serves me right the pump is always pumping when the machine is running and its the switching valve that directs the flow of fluids.You can confirm things by disconnecting the hose from the pump and adding another hose directed to a 5 gallon pain and crank the machine and see if fluids are moving.If so which im sure they will be then it may have a locked up diverter valve.you should be able to figure things out but will need a second person to feel the hoses as you flip the lever and you should notice in feel if there is a pressure build up.I dont think the tank repair is trhe issue as there is no pressure in the tank its just a holding tank.Good luck on it but id really look into the switching valve assembly if it were me...

Yep. The pump should move fluid all the time. Pumps to the valve. If no use, returns to the tank.

So the output of the pump could be checked for pressure. But this is a radical check. Can't think of any other term to use. The bypass for this system is in the valve. So if you plug the output hose of the pump with a gauge it is going to create tremendous pressure and risk blowing a hose or the gauge.

Very possible that something is fried in the control valve.

The relief valve could actually be inoperable and simply dumping back to the tank.

The valve plunger could be damaged and letting everything bypass.

Lastly, the pump could be damaged to the point that it's internally bypassing. Unlikely, but possible.

We are already assuming no pressure is being applied to the cylinder because of no action. Can't imagine that there's damage to the cylinder due to heated oil because it wasn't in use. A quick test of the cylinder would be as follows. Put the lever into float and raise the bed. Hold it in the raised position for a few seconds to allow the cylinder to vacuum fluid from the tank to fill itself. Move the lever back to the neutral position. The bed should remain elevated.

One more check would be to start the engine. Hold the lever into the raise position. Let the system run for a few minutes in that situation. If the pump is pushing fluid and simply bypassing back to the tank due to valve failure you should feel some warming of the fluid. Or if you can see into the tank you should see fluid movement.

More than likely heat is the cause of failure. All we are doing now is trying to determine where that failure is.

I have saw pump destruction because of this type of bypass stress. No major breakage in the pump. Just severe scoring of the gears and the housing allowing the pump to totally fail to move fluid.

Very interesting to see where this goes.

No Maybe I mis quoted.I would NOT put a guage on the output as it will blow a guage apart.Just pump fluids back into the tank or a clean bucket yo reuse.