Hyd Valves on a M930, How they work with the front winch

[M35A2-AZ]

I have a M929 and I plan to put a front winch on it. But I do have a question about how the Hyd valves are setup on the M930.
Does anyone have a M930, A0, A1, A2 that you could take some pics of the Hyd. valves under the truck?

I do not have a good understand how they run the dump and the front winch from the same PTO.

If you could PM me or email with the pics.


Well I understand now it is not the same Valve, The M930 using a two spool valve.

 

[M35A2-AZ]

I would like some photos of the valves. Thanks

 

[doghead]

Nothing in the parts TMs?

 

[M35A2-AZ]

Nothing in the parts TMs?

Doghead, I found the p/n for the valves and they are not the same for the M929 and the M930.
It looks like they took two of the valves and put them together to make a two spool valve.

I just would like to get a Photo of one from a M930,A1,A2.

 

[m16ty]

It's just a open center system with fluid flowing from the pump to the two spool valve. One spool of the valve controls the winch and the other controls the dump.

You'll need to replace your one spool valve with a 2 spool. I'm sure something aftermarket could be made to work if you can't find the correct valve.

There should be a pic in the parts TM of the different valves.

 

[M35A2-AZ]

M16ty, Thanks for the info.

 

[Tinydragon2001]

I'm just adding a single acting valve in line before the winch valve on my m925 so I can run the dump hoist and winch off the same pump.

 

[doghead]

If you do not need extra fluid for the hoist, a simple diverter valve may get you what you need.

 

[m16ty]

I'm just adding a single acting valve in line before the winch valve on my m925 so I can run the dump hoist and winch off the same pump.

I'll give a word of caution on that. I've done what you described before on different applications but all the valve manufacturers that I know of advise against this. What it does is cause back pressure on the outlet of the first valve in the series. Most valves aren't designed to have back pressure on the outlet and can cause the valve to fail prematurely. As I said above, I have stacked single spool valves before but I thought the possible consequences should be noted.

Now there is a way to do this correctly but but you'll need a valve with a power beyond port. What you do is have pressure in the first valve, the outlet from the first valve to the tank, and pressure from the power beyond port to feed the second valve.

 

[Tinydragon2001]

I did some reading, and you are correct m16ty. I don't have a valve with a power beyond. So what I'll do now is simply replace the winch valve with the valve I have. I'll remove the winch as well and use it for another future project. Dump is way more useful.

 

[m16ty]

I wouldn't pull the winch. You could just use a inexpensive diverter valve to switch between the winch and the dump. In other words, the winch valve you currently have can run the dump and the winch.

Also, there's no reason to replace the winch valve you currently have if you decide to pull the winch. It will work the dump just fine.

 

[doghead]

I thought I said that...

 

[M35A2-AZ]

So you should not tee off of the supply and return line for the 2nd valve?
I guess I do not understand were the back pressure comes in.

 

[m16ty]

So you should not tee off of the supply and return line for the 2nd valve?
I guess I do not understand were the back pressure comes in.

No, a tee in the system won't work. We are dealing with a open center system and everything has to be plumbed in series. Here's a pretty good link that explains it- http://www.valvehydraulic.info/hydraulic-circuit-design/hydraulic-open-center-system.html

 

[m16ty]

I thought I said that...

Yes you did but I guess it didn't sink in.

 

[M35A2-AZ]

No, a tee in the system won't work. We are dealing with a open center system and everything has to be plumbed in series. Here's a pretty good link that explains it- http://www.valvehydraulic.info/hydraulic-circuit-design/hydraulic-open-center-system.html

M16ty, Thanks for the info. and help.

 

[Andrmorr]

I just saw this thread and would be glad to help if it's still needed. I have a M930A2 and can get you pics of whatever you need. I'm looking into the hose routing of the winch myself because my winch runs backwards from what it should... pull back is out push in is winch in...hoping its just a hose swap but havent had the chance to map it out yet... Andrew

 

[M35A2-AZ]

I just saw this thread and would be glad to help if it's still needed. I have a M930A2 and can get you pics of whatever you need. I'm looking into the hose routing of the winch myself because my winch runs backwards from what it should... pull back is out push in is winch in...hoping its just a hose swap but havent had the chance to map it out yet... Andrew

Andrmorr, I would love some pics. PM sent.