# Central hydraulic help



## xtreem3d (Nov 26, 2005)

Hi Guys.
i need some hydraulic help/ I have an old municipal truck with central hydraulics. Just got a plow for it ..the plow goes up and down and goes left BUT not right. It has a joystick with 2 cables, one for up/.down/ and one for left right. I have traced the cable back to the manifold but i want to understand what comes apart when i try to take it apart. I can't find any diagrams anywhere (Google). Does anyone know where i could find a diagram of the valve parts?
The plow hasn't been used in years so is it possible something is stuck in place even though the cable will move the plow to the left?
Thanks,
Steve


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## csi.northcoast (Aug 7, 2010)

Yes there could be a couple of issues

the cable might be stretched or out of adjustment, the valve body itself could be stuck.

do you have a pic??

when you angle the plow, are you pushing the cable into the valve body that makes it currently angle or is it being pulled away from the valve body


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## xtreem3d (Nov 26, 2005)

Hi CSI,
The cable is being pushed into the valve body. I was by myself so I can't say that I could see the cable "bulge" or flex like it was hitting something. I don't have a pic tonite but I will take some tomorrow,
Steve

PS I just re read your post I may not have explained.properly.....Joystick left pulls the cable and moves plow left...... Joystick right pushes cable into valve body and nothing happens


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## Morrissey snow removal (Sep 30, 2006)

sounds like there in not enough throw in the cable take the cable off and work the vavles


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## White Gardens (Oct 29, 2008)

Ya, I would venture to say a stuck valve or something of the sort also.

At least you know that there is oil moving through the valve body if you've got other movement.

Check your quick coupler fittings for the left side cylinder that would push the plow to the right. Could be you don't have it fully on and it's not allowing oil to flow through it.


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## xtreem3d (Nov 26, 2005)

I have replaced the couplings hoping that was the problem but it wasn't. as far as taking the cable off I am not sure how to I guess. It is threaded into the valve body with a jam nut but it looke like you would have to undo he other end of the cable from the joystick to get the cable to rotate(turn)......like if you had a hose hooked to your plow and you tried to unscrew it at the ram, the hose would twist up unless you undid it at the pump first. I was hoping to avoid having to undo the joystick ends because it is very cramped in the cab where this was originally install, and the seats are in the way so if i don't have to unbolt 30 year old seat brackets that would be nice


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## xtreem3d (Nov 26, 2005)

Here is a pic of the valve assembly


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## White Gardens (Oct 29, 2008)

Your going to have to take the allen screws out holding the cable assembly to the valve body.

The end of the cable attaches to the valve in the body, so I'm thinking that the whole valve should slide out with the cable as the cable will be attached to the valve.

This is only a guess as I've never had one apart, but I understand how it all comes together.


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## xtreem3d (Nov 26, 2005)

OK that sort of makes sense. If I were to unbolt the allen screws then any adjustments must be made by screwing in or out the cable where it goes into that longer fitting that is held on by the allen bolts. Any idea if I have to worry about check balls, springs ect....as the valve comes out?
Steve
PS What are the caps on the backside of the valvebody do?. They are held in by 2 screws


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## White Gardens (Oct 29, 2008)

xtreem3d;1539365 said:


> OK that sort of makes sense. If I were to unbolt the allen screws then any adjustments must be made by screwing in or out the cable where it goes into that longer fitting that is held on by the allen bolts. Any idea if I have to worry about check balls, springs ect....as the valve comes out?
> Steve
> PS What are the caps on the backside of the valvebody do?. They are held in by 2 screws


From diagrams I've looked at, I'm pretty sure that it's just the backside of the valve and has a spring under the cap.

Here's what I would do first before anything.

Have someone in the truck holding the lever in the position you need it to move the plow. Then you push on the plow to try and move it back to the right. This might do the trick.

I had air in the lines of my old truck and had to do this in order to get it to move with a central pump, though a smaller under the hood plow pump, and not a full fledged central hydro system.

I'd try to get a part number off the valve body and look up some diagrams first before disassembling. If you can't find anything, I'd find a local truck builder or hydraulic shop and see what they have to say.

I personally wouldn't think twice about pulling apart that valve because of the past experiences I've had, but then again, I don't know your mechanical skills and don't want to steer you in the wrong direction.

.......


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## White Gardens (Oct 29, 2008)

Here's a simple diagram that might give you a little more insight.










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## xtreem3d (Nov 26, 2005)

Thanks for the diagram. I have already tried to move the plow to the right while pushing it against a dumpster to free it up but it didn't work. Another question...how does the cable end attach to the hole in the valve as per your diagram.
Steve


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## White Gardens (Oct 29, 2008)

The diagram I posted has what appears to be a lever controlled valve. From other pics of cable controlled units I've found, it appears there are threads on the end of the cable that probably thread to the valve or a hook of some sort that the Cable is able to slip over and tighten with a nut.


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## White Gardens (Oct 29, 2008)

Part of me wonders also if you take the spring end apart, you might be able to free the valve that way. Without taking the whole thing apart. It might be just stuck enough, along with the spring tension not allowing the valve to move. I'd take the spring cap off and the spring and start moving the lever.


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## xtreem3d (Nov 26, 2005)

OK I will look at it tomorrow.


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## jhenderson9196 (Nov 14, 2010)

In order to remove the spool from the valve bank, you must remove the cap from the back and unbolt the centering spring from the spool. Then push the spool out the front.


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## 99LsSilverado (Aug 28, 2011)

xtreme3d
If you are wanting to take the cable off and open up the valve I have experiance with this style.
I took your pic and made some pointers on what to do in order
1- Take off the jam nut all the way and let it hang on the cable housing
2-Take the two allen screws out of the valve housing
3-Back off the black plastic housing till off of the threads
4-There is a pin that holds the cable to the spool on the end 
5-Take off the the cap and the centering spring 
Then you will able to take the spool out 
But with what I have seen it is common to have the centering spring to break and jam up so it will only work in one fuction and not the other.
I hope that this helps you out


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## White Gardens (Oct 29, 2008)

And there you have it...........






..................


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## MatthewG (Jun 16, 2009)

Very informative


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## xtreem3d (Nov 26, 2005)

Thanks everyone...and thanks for the instructions 99LS..I will try it later today. My biggest concern is that the allen bolts in the front or the screws in the back holding the spring cap on will break off so I will try to soak them this morning and try later today,
Steve


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## jhenderson9196 (Nov 14, 2010)

Pull the back cap first. If it is just a centering spring problem you will save a lot of work.


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## 99LsSilverado (Aug 28, 2011)

No problem. And yeah you can pull the back side off first to check the spring.


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## xtreem3d (Nov 26, 2005)

Hi Guys,
I soaked the screws and bolts a couple are tough to move and I quit because I was afraid I'd break the heads off..so my question is...If i go ahead and try the front or rear cap and break one head off but get one loose and then tighten it back up will it leak fluid if the plow control isn't used? My reason for asking is the truck runs and the salter and dump work fine but I wouldn't want to break a bolt head then not at least be able to salt until I get this sorted out
Thanks in advance,
Steve


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## White Gardens (Oct 29, 2008)

Regardless of what you do, make sure you have the safety bar up when working under the bed.

I even add an 8' section of pipe in another spot for a little redundancy.


...........


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## 99LsSilverado (Aug 28, 2011)

Nope no fluid will leak out will just have the chance to break the other bolt but will be ok


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## xtreem3d (Nov 26, 2005)

I want to say thanks to everyone who responded in a helpful manner (that was everyone). And special thanks to LON ,you guys have probably seen his trucks outfitted on here. He was nice enough to send his phone number so that I could call him. After 3 phone calls I had it apart once I understood how stuff went together. It looks like the cable is toast so I am trying to get one made here. Attached is a pic of what is probably a simple repair but because this was on a 1982 truck inside a cramped cab with the controls in a terrible spot
we had to cut the passenger seat out with a sawzall because the bolts were rusted and not accessable. I am guessing this is an old time controller because it's a crazy assembly to take apart to remove the cable. Hopefully I can get a cable made and get it back together soon,
Thanks to everyone,
Steve


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## LON (Aug 20, 2006)

Could of never typed an explanation that would explain it. Was better to talk to you.
Now you understand what it takes us in the business to get this stuff out sometimes - "that looks simple, why'd you charge me for 3hrs when it should of only taken 1" LOL


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## xtreem3d (Nov 26, 2005)

Forgot I had another question.Here is the control joint that attaches to the left/right control rod. The ball doesn't snap into the joint it just goes in and out ...is that normal?
Steve


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## xtreem3d (Nov 26, 2005)

LON;1541448 said:


> Could of never typed an explanation that would explain it. Was better to talk to you.
> Now you understand what it takes us in the business to get this stuff out sometimes - "that looks simple, why'd you charge me for 3hrs when it should of only taken 1" LOL


 ..I kept thinking about what it would have cost to have it in a shop with all that went on.


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## jhenderson9196 (Nov 14, 2010)

The ball and socket should have a retaining clip that slips over the socket and holds the ball in place.


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## xtreem3d (Nov 26, 2005)

I don't have a picture here tonite but non of the pivots(plow up, plow down, plowL&R) had a clip. I don't even think the dump bed up/down has a clip. You may not be able to see it but there is no spot for a clip..that I can see
Steve


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## jhenderson9196 (Nov 14, 2010)

It's a barrel shaped device, made of spring steel, that slides over the of the socket and retains the ball end.


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## xtreem3d (Nov 26, 2005)

Maybe they have been removed after all these years? but the controls still work


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## jhenderson9196 (Nov 14, 2010)

It's possible. I have safety wired those type of connections together in a pinch.


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