Hino N209

[htiek126]

I just installed a FEL and backhoe on my N209. The hydraulic fluid seems to be running very hot. The backhoe and FEL valves are very hot to the touch. You can hold you finger on them for a few seconds at most. How hot is normal? Is this generally a valve issue or some other restriction in the line? I used 3/8" hydraulic hoses. The three point hitch now raises slowly with no load. I suspect maybe one of the electric solenoid three point hitch valve seals is now leaking after being aggravated by the heat. I am on the right track or could it be something else?

 

[buppy69]

It will run very hot. Pressure causes heat. Your lift is slow because now you are diverting part of the fluid to the front loader.

Eugene

 

[Slamfire]

If you can hold your finger on a fitting, the temperature will be less than 130 degrees Farenhiet. Over that, and you'll snatch your had away. When operating in a thermal generation station they told us all kinds of good stuff, like use the back of your hand if there is any possibility of stray electricity, then when your muscles contract, your hand will come away automagically. /forums/images/graemlins/crazy.gif

 

[EFC]

As long as you’re not activating the loader at the same time the 3 point should lift at the same speed it always did. If it is plumbed in series correctly then you have a partially plugged hose or line. If you had hoses made they could have crimped the end to far ( I would pull off ones that look like they are smashing the hose to much and look down it to see if it was crimped smaller than the ID of the hose. Any chance you’re plumbed in the wrong direction on your loader or backhoe valve. Give me a detailed description of the system from A-to-Z on how you plumbed it and the valves you used and we can figure it out quick.

 

[htiek126]

Clarification - The FEL, backhoe, and three point lift work great with the one exception. The three point hitch slowly raises on its' own when not loaded. I am not activating the valve, and I can also push the top limit switch to break the electric circuit to the valve, and it still raises.

The system:
I tapped into the tractor hydraulics at the hydraulic access block (under left driver's foot). I simply ran 3/8" hose from the pump/pressure side of the block to the FEL valve (P), from the FEL valve (T) to the backhoe valve pressure line, and then from the backhoe return line to the hydraulic access block where it travels to the three point hitch valves.

The heat:
I suspect some of the heat issue may be too much flow for the Koyker B60 backhoe. I believe the manual says the flow should not exceed 4GPM, and it looks like the backhoe cylinder hoses are 1/4". I have not idea of the flow rate for the N209, but I am very happy witht he response times on the Koyker 155 FEL. I like running the backhoe fast, but I suspect that I am running it a little to fast because it is more jerky then my past experience with a Bradco backhoe on a JD870. Of course, some of that is operator error....

 

[EFC]

I have to assume that the 3 point problem started when you plumbed for the loader and was not occurring before? Doesn’t really matter either way you have a spool sticking in your 3 point valve. I run the KB60 on tractors with 8 to 12 GPM with no noticeable heat. I would say that the partial flow that is constantly being diverted through your 3 point spool is causing the heat. No doubt in my mind. Time to tear it apart and get her fixed. /forums/images/graemlins/grin.gif

 

[EFC]

I was just kicking myself; it is important to know if this happened before or after you installed the loader. If it happened after I would bet lunch that you have a piece of Teflon in the spool area or debris...... the orifices for the hydraulic amplification are extremely small and I spend a fair portion of my life digging out Teflon tape and small pieces of muck......

 

[htiek126]

The problem started after the first day of use the FEL. I suspect you are right about debris. I noticed the problem that night when I removed the backhoe.

I blew the lines and fittings out with compressed air before installing. However, a few fittings required some trial and error refitting and there were some key moments that I was unable to control debris falling into two vertical sections of hoses. There is no teflon tape involved, but I did use thread lock hydraulic sealer and some of the fittings already had some other pipe sealing compound.

It sounds like it is time to tear the valve apart and clean...

Are there any words of caution or wisdom about tearing a valve apart to clean? Or do I just need to be methodical with a clean bench top?

 

[brianidaho]

Is it possible that your plumbing is not unloading the pump when all of the valves are in their "neutral" position? I'm a newbie to tractor hydraulics, but have a fair amount of experience with industrial hydraulic systems. How long does it take to heat up, and can you hear the motor load slightly when any one of your attachments are actuated (you should hear this)? If things are heating up quite quickly (say 10 minues) it almost sounds like the pump is up to pressure and popping off the relief valve. All that power that goes into the pump to drive fluid goes directly into heat when the hydraulic cylinders are not actuated.

Again, newbie speaking here, but my Shibaura appears to have both the FEL valve and the 3-pt valve with a "tandem center" mode, where the pressure line dumps to tank with nothing operating. On mine, there is a (manual) ball valve supplying the FEL, it has to be closed to maintain pressure in the system and operate the 3-pt. Conversly, when the 3-pt is in the center position (solenoid unactuated) there is no pressure to operate the FEL, the 3-point sol must be energized "up". With both of these valves closed (3-pt up) the motor loads and you can hear oil flow over the relief valve. It heats up in about 10 minutes then.

I have no idea if my setup is typical or if this relates at all to what you are seeing, but if you are heating up that quickly, somewhere you are probably bleeding from the pressure side of the hydro system to tank. A stuck valve such as Buck describes would do exactly the same thing.

A question to you hydraulic experts here-what style of pump do tractors typically use, a vane or piston? Are these typically a "pressure compensating" (aka variable displacement) style where the displacement of the pump goes to zero when there is no flow?

Hope this helps.

Bri

Edit: I didn't read your last post carefully enough-that fact that your 3-point is drifting up almost certainly means the valve isn't returning to center properly, stuck between up and "hold". Would explain both the 3-pt travel and heat. Sounds like Buck is spot on again-should have known /forums/images/graemlins/wink.gif. Does the 3-pt drop normally? If so, you may be able to cycle the valve a few times and dislodge whatever is sticking things, fluid flow should flush it out then.

As to dismembering a solenoid valve-as you said, have a clean bench, note which o-rings go where (there may be several where the valve mounts, or one gasket) and don't force things. If the spool seems to stick in the body, work it out slowly and carefully. When you go to re-assemble, put a bit of oil on any o-rings, work carefully so not to cut them. If there are some between the valve and base you might want to "tack" them in place with some heavy grease, its pretty easy to shift and cut one when putting the valve on.

If worse comes to worse, are these valves a "industry standard" mounting?

Good luck.

 

[htiek126]

It does heat up quickly, 10 minutes might be about right.

I believe these tractors have gear pumps.

The 3pt goes up and down properly. It is the off position that it just slowly rises on its own. I have cycled it quite a few times to see if it would fix iitself. No such luck yet.

I doubt these are industry standard valves.

 

[brianidaho]

OK, thinking things through a little more and reading the description on your plumbing. IF your system was set up like mine, prior to adding the backhoe and fel, your hydro system should have unloaded (tied the pressure line to tank) with the 3-pt valve is in the neutral or down position. Pressure would build (Pressure to tank blocked) only when the 3-pt is being raised.

You indicated that you went from the pressure port on the hydro access block in to the FEL P-port, FEL T to Backhoe P, Backhoe T to what would be the 3-pt P. All return to tank would be through the 3-pt valve, correct?

OK, if I am on top of things, if the 3-pt valve does have a tandem center position (pressure to tank), which would unload the pump, there should be no pressure in your system, assuming all of your valves are the same center style. If you are ideling, with the 3-pt in the hold position can you hear your engine load slightly? If so, does it unload when the 3-point switch is held in the down (float) position? If so, you might want to run her at speed with the 3-pt valve in the down position for the 10 minutes or so and see if it stays cool then.

With the series plumbing, all of your valves have to tie the pressure port to tank with the valves in the center position, otherwise you don't have flow downstream. Since you can operate your downstream components, it sounds like the proper spools are in the fel and backhoe. (In industrial hydraulics, a closed center valve is common, to maintain pressure in the system). Does your 3-pt raise at it's normal speed? If it's slow, you could have a restriction upstream somewhere. You can often hear oil flow (sort of hissisg) through an obstruction, and you should be able to feel around and see where your plumbing first gets hot.

Lots of speculating here, my setup is plumbed in parallel, rather than series. Based on how quickly you are heating up, it is most likely that you are not unloading the pump (dumping pressure to tank) when not operating a valve. Biggest suspect based on everything you've said, is the 3-pt valve. Is it hotter than the fluid inlet line? Also, can you find the relief valve in your system? If so, can you hear fluid flow over it? By rights, the only time there should be flow over the relief valve is when a valve is actuated, with a cylinder at full extension/retraction.

Good luck.
Brian

 

[EFC]

Pumps are open center gear pumps.

Bypass valve is built into the solenoid block

Solenoids are a job for a clean bench and patience. You can do it just be methodical about what goes where. Do not use sand paper or a file on ANYTHING!! just disassemble. To test the valve before I spend two hours putting it back on I use an air nozzle with a rubber tip to the inlet side of the solenoid and make sure my bypass is seating then I connect it to a battery and make sure that each spool activates correctly. If you can map out the fluids path through the valve from A to Z troubleshooting will be a lot easier.

Brain, they are going to have to put in a separate hard drive in the server just for you /forums/images/graemlins/grin.gif just kiddin!

 

[htiek126]

Good news. After my last response, I noticed the hydraulic system was running much cooler. I finally got a chance to remove the backhoe yesterday, and the three point hitch has also fixed itself. So it appears the two problems were related as Buck surmised. Of course my luck is not free, I noticed a 16 penny nail stuck through the front tire and tube while I was removing the backhoe. It is still easier to fix then tearing apart a valve.

 

[kayssupply]

When you put the hoe back on be careful not to move the 3 point lever while it is on. I moved mine while using the tractor with the loader. It put a terrible load on the pump and engine . It was trying to lift the hoe that was locked down with the draw bar arm. I tied my lever down from then on whenever I was using the hoe.

 

[htiek126]

My three point hitch controls are electric. I was thinking about putting a cut off switch on the system to prevent damaging the tractor with the hoe attached. Right now, I am adding metal to the draw bar plate that attaches to the two top links. It did not take long to bend that plate. I have three bolt pattern for the plate instead of the suggested 4 bolt pattern.

 

[kayssupply]

That is a pretty good sign something was done that shouldn't have been. I learned also the 3 point hoes don't really have the strength for moving the whole machine using the hoe like a full size machine can do. It puts exteme stress on parts like the one you describe. Luckily mine was on a Yanmar with powershift and I could just move forward with out getting down and getting back in the driver's seat every time I needed to pull up.