Finally, Hydraulic Backhoe Stabilizer Locks, Lift and Lock,

[WaxMan]

Not sure I follow what you are saying here.

A NC poppet valve on the rod side (only) would lock the outriggers with the tractor off. Forgetting to switch
the valve ON when using the hoe does not cause a problem as the poppet is forced open. You
can even install a microswitch that is triggered to turn the valve ON when you move the control lever.

I love these small monoblock solenoid valves that require no base plate. I also use spool valves of this type
for my hyd thumb and 4-in-1 FEL bkt..

I am looking fwd to hearing the results of your base-end cutoff valve experiment.

The Hydraulic Lock valve is the way to go, time tested safety device with only two lines in and two lines out all switching done by the valve internally. At some point I'll do that.
But first I'm going to try moving the valve as you suggested to the piston port.

 

[WaxMan]

I am looking fwd to hearing the results of your base-end cutoff valve experiment.

I put the valve at the other end of the piston today.
A quick test is , With the valve closed and the tractor off I was able to lower the leg to the ground as if no valve was installed. So the valve does not work on the base-end piston port.

There was no need to leave it there for a few days and wait and see.

With the valve at the dangerous port you cannot lower the leg with the valve closed and tractor off.
The stabilizers remained upright all week long and didn't move at all.

 

[dfkrug]

I put the valve at the other end of the piston today.
A quick test is , With the valve closed and the tractor off I was able to lower the leg to the ground as if no valve was
installed. So the valve does not work on the base-end piston port.

That is what I expected, but there is no substitute for actually trying it. If you put your ear up
to the gland when you are pulling down on the outrigger, you may actually hear air getting
sucked in past the seal.

 

[techman]

I put the valve at the other end of the piston today.
A quick test is , With the valve closed and the tractor off I was able to lower the leg to the ground as if no valve was installed. So the valve does not work on the base-end piston port.

There was no need to leave it there for a few days and wait and see.

With the valve at the dangerous port you cannot lower the leg with the valve closed and tractor off.
The stabilizers remained upright all week long and didn't move at all.

Simple explanation: You would be trying to hold up the stabilizer with a vacuum. That is only 15 psi if there is no seal leakage. All seals do leak, and most of them are "energized" (industry term) by the pressure behind them. With a vacuum behind the seal, it will do a poor job of holding. Also if the induced weight exceeds the available 15 PSI, then you will just have a vacuum in the cap end of the cylinder and it will also fall. Your rod end scheme is the best, but has inherent risk.

paul

 

[WaxMan]

Simple explanation: You would be trying to hold up the stabilizer with a vacuum. That is only 15 psi if there is no seal leakage. All seals do leak, and most of them are "energized" (industry term) by the pressure behind them. With a vacuum behind the seal, it will do a poor job of holding. Also if the induced weight exceeds the available 15 PSI, then you will just have a vacuum in the cap end of the cylinder and it will also fall. Your rod end scheme is the best, but has inherent risk.

paul

I was pretty sure it wasn't going to work based on how I checked it in the beginning. I loosened the end fitting, no oil came out. I loosened the rod end and oil came out - it started to drop.
I was 99 % sure it would not work with the valve at the other end. dfkrug was curious, which then made me curious. Imagine after all this write up and thought, someone comes along and says just put the valve at the other end, Mine works fine on the other end.

It is too bad there is not a simple on/off valve with a built in fluid bypass if under high pressure one way. Do you know techman if such a valve exists?

Just want to Thank You again techman:thumbsup: for bringing this to my and others attention of the danger and problems that could /will arise from installing a valve at the rod end.

This is a perfect example why these forums are a good place to hash out ideas, and is one of the reasons why I share what I have done and what I want to do to my tractor.

When I post a New Mod I'm also looking for input on how to make it better. Please don't anybody ever be afraid of offending me or to offer suggestions, criticize or leave feedback good or bad, as in this case a warning.
But if you want to post negative stuff for no other reason then jealously or spite, as was that one case before, just move on.

 

[techman]

There are several solutions available. A small relief valve connected to the rod side and vented to the bore side would work. The problem is that a small valve needs to be put into a connection block, which greatly increases the size. Not a large as an earlier posed pix, but like 1.5" square by 3" long is approx. Also a PO check valve could be used. This would be blocked until piloted open by pressure tapped off the bore side. Again the connection block gets large again. perhaps there is a smaller relief/connection block available. One would need to search.

Paul

 

[NoNewParts]

While I just use a piece of heavy chain between them when up
(hydraulics can't break it, and impossible to forget....it's in my way... and what's another chain laying there. handy for chaining the bucket to something too)

Your idea sure looks good and with techmans warning, you know to not forget.
If you have a lot of parts, just adding another shutoff to the other line too would solve it.
Locks the cylinder and if you forget, just deadheads the pump into relief in either direction.

Another idea is some old tractors have 'diverter valves' after the main control valve.
2 lines from the pump/valve in, 2 out in position A, 2 out in position B.
Putting plugs in position B and your cylinder lines in position A, and you are good.
Park it, turn it to position B and the stabilizers are locked up, and both lines are deadheaded into the plugs in position B if you forget.

 

[dfkrug]

A small relief valve connected to the rod side and vented to the bore side would work.
The problem is that a small valve needs to be put into a connection block, which greatly increases the size.

If an RV is used in conjuntion with a ball valve in the rod end, then they can be fairly small, and does not have
to be installed near the cylinder itself. Here is a Hydraforce RV that I ordered with a fixed 2000psi relief setting,
and the shipping was more than the valve itself cost. Since the outriggers are intermittantly used, you can
size these units fairly small.

I used this crossover RV with two of my hydraulic chainsaws.

 

[crazyal]

While it's not fool proof have you thought about just putting a valve on both lines? It's pretty unlikely (but possible) that you would open one valve but forget to open the second. With a little bit of designing you could tie both valve handles together so both could be opened and closed with just one handle.