Need help with Husco hydraulic control valves....on a bucket truck

[hellspcangel911]

Hi All,
This forum has been a life saver when it comes to keeping my older tractors and loaders running on the farm. I recently purchased an older bucket truck to help with building the barn and other tasks around the property. The truck has been well serviced and cared for by a large electrical contractor, it has a joystick and three extras hydraulically actuated jib, winch and bucket tilt.
I'm running into an issue with the controls for the three extras. All of the other controls work both from the joystick and lower controls. I have lower controls for the winch (which works) but not for the bucket tilt and jib actuation).

The truck has one large PTO Muncie pump, no other aux pumps and no electronics. The upper Husco control valve 6480-142-2 (joystick) has a hose running off of it to the 3 spool mini valve (6060-59-201) which controls the winch and jib.
Theres a line coming out of the unused 3rd spool connecting to a block (not sure of its purpose but it has three lines connected to it) and going to the bucket tilt spool.

Since the winch works from the lower controls but not the upper I assume theres an issue with not getting pressure from the main control valve into the 3 spool mini. When I operate any of these three controls I can feel a slight pulsing in the hydraulic line connected to each unit, but not enough to work anything.

I've searched and posted on bucket truck and arborist forums without success. Since these are relatively standard Husco valves and discussed with much more knowledge on this board I was hoping to get some suggestions on what to check or where to start.

Any hep would be would be greatly appreciated.

Thanks!

 

[ptsg]

Could there be a diverter valve somewhere that would switch from the lower controls to the upper controls?

 

[hellspcangel911]

there is, but the rest of the upper controls work, and the three controls that are not working are plumbed off of them.
the main line comes into the Husco 6480 (joystick) control valve, a hose goes from that to the Husco 6060 3 mini spool, then from the 3rd unused mini spool it goes to the bucket tilt controller. All of it is plumbed correctly according to the Husco and Holan manuals and no doubt worked before. Its as if theres a clog somewhere or safety valve or device not functioning properly.

 

[hellspcangel911]

So the line with my finger on it is the supply for the 3 mini spool (and subsequently the bucket tilt). The mini spool is located under the joystick with the controls on the other side (the two yellow long linkage knobs)

 

[ptsg]

What about that capped line just under your hand? Does it matter for your problem or it's for something else?

 

[ptsg]

Oh I think I've found something. So the line you're pointing at, comes from one spool on the main control valve (Husco, right?).

It seems that you have to push some lever to force the fluid to go from that spool to the mini valve, therefore feeding the circuits there.

So if you find the linkage on that spool, you need to move it either way and try the mini valve. I almost sure that is the thing you have to squish on the joystick, to activate the mini valve.

I believe they did it this way because the Husco valve doesn't have Power beyond the feed other valves.

 

[hellspcangel911]

As for the capped line, I can稚 find what it goes to but per the Husco manual everything is connected properly. I believe the line was never used.

Correct the line comes out of the main Husco control valve into the mini. The finger paddle/trigger on the joystick locks out the joystick. It must be depressed in order for the joystick to work. I致e tried holding it and using the mini spool controls and bucket tilt but it still doesn稚 work.
So your read on this is that the something must activate that last spool on the main control valve in order for the fluid to flow to the mini spool? If that痴 the case I値l take apart more of the covers on the joystick and dig deeper into the linkages .
Also, what do you mean Power beyond the feed? If there痴 an issue with that last spool on the main control valve can稚 I just Tee into the inlet on the main control valve to the mini spool?

This is very helpful, thank you so much!

 

[ptsg]

So your read on this is that the something must activate that last spool on the main control valve in order for the fluid to flow to the mini spool? If that痴 the case I値l take apart more of the covers on the joystick and dig deeper into the linkages .

Yes, that's what I think is the missing step to active the other valve.

Regarding the "Power beyond the feed", I really wanted to mean: "Power beyond to feed". It was a before dinner post, so brain doesn't always work as it should

 

[/pine]

FWIW...Just an outside guess...but many mobile rigs I have seen have a combination of both open center and closed center circuits depending on what they do...this is especially the case where there are two or more valves controlling the same cylinders/motors/devices etc...

 

[oldnslo]

Are the joysticks hydraulic pilot style where there are two hoses from the joystick for each valve function?

From the pictures I suspect yes but not certain

If yes you need a pilot supply pressure usually less than 500 PSI possibly as low as 250-300 PSI.

You also need a tank line with very minimal back pressure