2006 RTV900 dump bed not working

[D&D Farm]

They surely make gauges to check output of hydro systems. I had to buy gauge to check the output of my fork hydros on my tractor when I was replacing shims in the control passages of the pump controls/levers.........I put that gauge on the end of the hose to see how much pressure it was building after adding a shim or replacing them............

What was running or causing the fluid to get so hot. Border Collie refers to this above when she added a cooler to her lines and the hole in his tank is what I was referring to in my above comment.................What was causing this heat? Yes, of course work; but friction in the pump? Where was the friction..........??

Ok, so the guy kept running it without the cooling that the fluid was giving though inadequate. What part was running so hot to cause this and wouldn't that be where the damage is?????

 

[ovrszd]

We aren't sure what type of splitter he was using first.

A splitter without it's own valve would use the RTV valve to open/close. This type would create heat but that heat should be minimal. No different than repeatedly using an FEL on a tractor for example. My assumption would be the tank could handle that much heat.

A splitter with it's own valve would only use the RTV to supply pressurized flow. The RTV valve would have to be tarp strapped into the raise or lower position to cause that flow. The splitter valve would then control the splitter cylinder and, if an open center valve, would simply dump back thru the RTV valve when not being used. No excess heat beyond what I mentioned above.

A splitter with it's own valve that is a closed center valve "could" create this problem. In this scenario the RTV valve is held "open" so it's applying pressure thru one port to the splitter. When the splitter valve is activated this pressure is used to open or close the splitter. The problem is when the splitter valve is NOT activated. At that time the RTV is deadheading against the splitter valve. This would force the RTV pressure relief valve to bypass. This creates hazardous heat. Same thing would happen if you held your FEL valve on your tractor after the cylinder you are running has reached it's maximum stroke. Not good.

If this scenario is present the pump is at some risk. Hopefully some part of the valve would fail first. That remains to be seen.

 

[Alaskanassasin]

We always used a flow meter on hydraulics.

 

[bordercollie]

I took a few pictures of my pump. The pump has a horizontal lever on top and goes up and down just a small amount when the front lever by the seat is moved . This operates the pump's moving the dump bed cylinder up or down. The cable from the front lever connects to this. That's the cable running through the back of the rear brace. bordercollie

Yes it is dusty- I used Fluid Film back there so it does attract the dust... plus... it is true.. I havent washed it in a coon's age.

 

[Cajunrotor]

I wish that I had something of value to contribute to this thread, but I am REALLY enjoying all the great brainstorming going into this! I've learned several things about the RTV hydraulics already. Thank you all for sharing your ideas and expertise. What a great forum!

 

[Alaskanassasin]

I'm ready for a update from jdg!

 

[ovrszd]

Collie, actually what you took a picture of is the control valve. The pump is located on top of the transaxle. Has two hoses fastened to it. Largest one goes to the reservoir. Smaller hose goes to the control valve that you pictured.

My RTV is at the farm. When I go down there this morning I'll try to remember to get a picture of the pump and post for reference.

 

[bordercollie]

ok .I just saw where that is where the cable produces movement and am not the best with words or pictures haha. collie

 

[jdg2259]

hey Guys, sorry for the delay... the hydraulic res. will be here tomorrow but I did confirm the lever is working and I raised the bucket up while in float and kept it there for 4-5 minutes, then I took lever out of float and the box came down to about 6 inches off the frame... it didn't go all the way down though until I lowered it with the lever. Tomorrow I'll have more of an update regarding the fluid and how its reacting in the res. box.

 

[bordercollie]

Good, I'd be sure to use proper fluids if it were me, when replacing the reservoir- no telling what kind of oil is in there now and if it is contaminated or not or the non foaming kind. Best wishes to you jdg2259. collie

 

[ovrszd]

Here's a pic of the pump. It's the steel canister sitting on top of the transaxle. The hydraulic hose with two red bands is the supply hose coming from the tank. The output of the pump goes to the valve. Valve is unseen behind the tube frame crossmember in the upper portion of the pic. You can see the cable that was in Collie's pic going to the valve.

 

[ovrszd]

hey Guys, sorry for the delay... the hydraulic res. will be here tomorrow but I did confirm the lever is working and I raised the bucket up while in float and kept it there for 4-5 minutes, then I took lever out of float and the box came down to about 6 inches off the frame... it didn't go all the way down though until I lowered it with the lever. Tomorrow I'll have more of an update regarding the fluid and how its reacting in the res. box.

So what that test showed us is that the cylinder is functioning. Oil didn't squirt out of the ram seal. And it held the bed up.

We also learned the neutral portion of the valve is still sealed. If not the bed would have fell when the lever was placed in the neutral position while the bed was elevated.

We still don't know positively where the problem is. My next step would be what Mark suggested. Remove the pump output hose at the valve end. Secure that open hose end so it dumps into a container. Bed elevated so you can see, standing by the machine, crank the engine keeping your hand on the key. As soon as it fires up fluid should gush out of the open hose. If the pump is working you'll only have the engine running a couple seconds.

I would perform this test with the old tank in place and the current fluid still in it. You are going to throw that fluid away anyway so might as well check the pump output with it.

In the confusion I can't remember if you ever confirmed that the fluid tank is actually full?

 

[Alaskanassasin]

The lift cylinder is probably not your problem but I think to lift it manually and lock it in place using the controls cannot rule out a bad seal on your lift ram as it is not under anywhere near the pressure it would be if actually operating the lift. I still think you should just loosen one of the hoses on the lift cylinder and operate the controls, there should be hydraulic fluid spraying everywhere then you know if your even getting fluid to the cylinder.

 

[D&D Farm]

I don't understand why you cant put a gauge on one of the hydro lines and measure the output.......Anyway, when you have the bed up, it should stay there even overnight. When you take it out of "float" the bed should softly go all the way down....NOT stop partially down. Something out of adjustment?.....Still trying to go up???..........

 

[ovrszd]

His test was accurately done and the results normal. Detenting the lever into float and manually extending the cylinder causes a vacuum and it draws fluid thru the "floated" valve into the barrel port of the cylinder. There could be some air drawn in as well. When the load is placed on the cylinder it may sag as it comlresses that air, but should carry the weight of the bed at some point. It did that. Proved the cylinder gland is intact. Proved the neutral position of the valve is sealing.

When he removed the valve from the detented float position it spring loaded to center or neutral position and should hold the bed up.

 

[ovrszd]

The lift cylinder is probably not your problem but I think to lift it manually and lock it in place using the controls cannot rule out a bad seal on your lift ram as it is not under anywhere near the pressure it would be if actually operating the lift. I still think you should just loosen one of the hoses on the lift cylinder and operate the controls, there should be hydraulic fluid spraying everywhere then you know if your even getting fluid to the cylinder.

Because his system won't even attempt to lift the bed but the cylinder will hold it up, his catastrophic failure isn't in the cylinder. That's not to say that there isn't some internal leakage. Just saying that's not the main problem.

This gets very complex and easily misunderstood. If the cylinder is extended in an isolated situation, meaning both ports are closed, as in the valve in neutral and functioning properly, the cylinder CANNOT collapse. Even if the gland seals are removed it can't collapse. To collapse the ram has to enter the barrel. In an isolated situation that would require the contained fluid to compress. That's simply not possible.

With test performed we primarily confirmed the valve is sealing when in the neutral position.

Loosening a hose fitting at the cylinder and activating the system has merit.

If pressurized fluid is present we proved the system is working.

If pressurized fluid is not present we proved the system is not working.

Problem with starting at that end of the system is we won't confirm where the problem is?

By starting at the pump and working our way toward the problem we will define exactly where it is when the results fail.

 

[jdg2259]

Well it appears to be an issue with the valve. As we were changing the hydraulic res. box out we checked to make sure fluid was coming from the pump (and it is). Also, now that we have good fluid in the lines the box will stay up all night and nothing appears to be leaking. Can the valve be rebuilt or does it have to be replaced completely? I think there over $800 to replace... ouch!!

 

[Alaskanassasin]

Well it appears to be an issue with the valve. As we were changing the hydraulic res. box out we checked to make sure fluid was coming from the pump (and it is). Also, now that we have good fluid in the lines the box will stay up all night and nothing appears to be leaking. Can the valve be rebuilt or does it have to be replaced completely? I think there over $800 to replace... ouch!!

the pump can still move fluid but not enough or under enough pressure to operate valve. I think I would do a flow test on the pump before throwing $800 at it... sometimes it makes sense to take her to the dealer get a diagnosis and proceed with repairs via ebay

 

[D&D Farm]

the pump can still move fluid but not enough or under enough pressure to operate valve. I think I would do a flow test on the pump before throwing $800 at it...:

It's totally easy to hook a guage up to the pump, hose, or valve..........Then you KNOW what pressures you are getting VS what you are supposed to have......

https://www.bing.com/images/search?...qpvt=hydraulic+fluid+pressure+guage&FORM=IGRE

 

[bordercollie]

My Dad's business was building hydraulic steering systems for off shore boats but he repaired valves and pumps all the time. He had a red box full of o rings and would take valves etc. apart and the o rings being replaced would solve many issues - sometimes the pumps had to have parts though. He had a hydraulic pressure reader that helped him pinpoint the problems .
When you were trying it out , I wonder if the pump or valve got hotter than the other to the touch? collie