Hydraulics question

RWB · Sep 27, 2003

Ok here it is I want to add a snow plow to the front of my nortrac 204C. I want to use the the tractor hydraulics and it is about 8.8GPM using 1/2" tubing. The hydraulic valves for the plow are I think 3/8" which would restrict flow adding heat to system. Would placing plow system parallel to tractors allow the fluid to continue to flow and still have the flow required to lift and tilt plow. I'm a newbie to hydraulics. I know on this tractor I can't allow the hydraulics to dead head so if I restrict it will it also hurt/blow pump. /forums/images/graemlins/confused.gif HELP.

Thanks

Ray Beck

Rch · Sep 27, 2003

RWB, a big consideration is what do you already have to work with. /forums/images/graemlins/confused.gif Do you already have a front end loader ? Will the snow blade mount on the FEL arms or it's own mounting system on the front ? Snow plows usually lift and angle so 2 hydraulic circuits are needed. The actual movments are pretty minimal so the 3/8 - 1/2 " reduction probably won't matter much. In an open-center hydraulic system the oil restriction of the 3/8" valve probably won't matter, especially in cold weather. Do you also want to leave the bulk of a FEL in place for using the front bucket as an adjunct for snow 'wrestling' ?

RWB · Sep 27, 2003

Hi Rch,
I do not have a loader. I plan on putting a sub frame under unit. Using existing hydraulic valving from plow and tying it into the tractor Hydraulics.

/forums/images/graemlins/crazy.gif
Ray

Rch · Sep 27, 2003

I have no experience with a chinese machine. I assume it's an open center system. I would be looking for a similar machine with a FEL to see where the hose come off to go to the valves and where the hose(s) go after the valves to dump their oil back into the tractor.

If you have power steering that works off the hydraulic system there will be a priorty valve in the circuit first as the pressurized oil comes out of the pump that gives the steering first dibs (if there is a seperate hydraulic pump for the power steering, usually run off a fan belt, that won't be needed) Next in the circuit there will be a "diverter block" with some sort of slotted or hexed head that divert the flow first to the 3 point hitch or FEL circuit by turning it a quarter turn. Since you don't have a FEL I think this would be set to direct the pressurized oil to the 3 pth. On the diverting block there is a port to tap into in order to add a FEL or other circuit. If such a circuit is added the diverter valve needs to be turned that other way, usually a 1/4 turn. The diverter block also will have a hydraulic tube coming out of it going back to the 3 pth.

As the hydraulic oil goes through the control valve that run the cylinders and exits the valves a hose dumps it back into the transmission case which is also the hydraulic fluid resevoir.

How many ports are on the valve housing (assuming the 2 valves are all in one casing )that run the snow plow ? If 6, one for pressurized oil,2 for each push/pull cylinder (4) and one for pressurized oil to exit the control valve (PB or power beyond) and return oil to the transmission then you are in business. If there is another port you may have a "regenerative circuit". Cross that bridge if you have to- that's where a tractor with a FEL already on it would be helpful. Seems complicated when explaining it but not really- the hydraulic oil is pumped out, flows through the control valves back to the transmission(open center) UNLESS directed by the control valve to the cylinders. The diverter block is the place to tap into another circuit in addition to the 3 pth. If the other circuit only works with the 3 pth all the way up turn the diverter valve that 1/4 turn.

http://www.adtdl.army.mil/cgi-bin/atdl.dll/fm/5-499/toc.htm
Here is a link to an Army manual re hydraulics

RWB · Sep 28, 2003

Hi RCH,
Yes it was alot to digest. As a newbie I'm slowly coming up to speed. Yes it looks like 5 ports. 1 Pres in - 1 out and the 3 for the cylinders. One spool to turn both left and right cylinder (as if a single 2way ram) and the one spool for the raising of the plow. I appreciate your help and I seem to be understanding the hydraulics better. This is a great site. And along with the chinese site it is a big help.

Thanks a million. I'm sure I will have more questions down the road.

Ray /forums/images/graemlins/grin.gif

Harrygoodwrench · Sep 28, 2003

Hi Ray, Harry here.
I see you are hard at work trying to solve our hydraulic dilema.
I know for fact that a fisher plow control vallve is a nomally open(centered) diverter with 2 spool valve for up/down and left/right angle. We have to find a way to utilize this valve into the existing hydraulic system without causing restriction. My idea /forums/images/graemlins/confused.gifalthough it may be wrong is to put a feed from the steering hydraulics (and eliminating that QD between the pump and steering diverter with a hard line as it can only lead to problems if it becomes disconnected)to another diverter maybe with power beyond and then it leaves the ability for future updating such as FEL or other implements.
I have some ideas on the plow mounting and to partially make the FEL mount and use it for the plow mount. I'll get some PIC's of the tracor frame/mount areas and send them to you but not today as it is pouring rain outside.

Everyones help/input is appreciated. Thanks, harry G

Harrygoodwrench · Sep 28, 2003

Forgot....
If anyone knows where Ray and I can get adapters, metric to SAE, lines, tubes, banjo type lines it would be very much appreciated as we are having a difficult time locating them...........Thanks again Harry G

Rch · Sep 28, 2003

Harry, what's "QD". /forums/images/graemlins/confused.gif

Also, with 5 connections of hoses on the valve assembly (oil in, oil out & 3 to the 2 cylinders, it sounds like the cylinder{that probably raises the plow up} with the single ram only pushes the ram out and weight pushes it back in, i.e. there is only one hose to it, on the end opposite where the ram pushs out .

Another thought is there is no diverter block if the tractor came without a FEL /forums/images/graemlins/frown.gif

RWB · Sep 28, 2003

Hi RCH,

Yes thats right the plow lift is as you discribe. QD is quick disconnect. Harry and I live in the same state and are working together to mount plows on our tractors. We do appreciate the help you have been giving us.

Ray /forums/images/graemlins/grin.gif

RWB · Sep 28, 2003

Hi Harry,
Rain is like cats and dogs here too. I agree with you on the replacement of QD. Sounds good on the ideas for mounting. Will be waiting for them. Did you get my e-mail on plans? DcH has been helping me and is doing great on getting my thick head to undersatnd it. I feel we will have this lick soon

Ray /forums/images/graemlins/smile.gif

Rch · Sep 28, 2003

Harry,let me see if I got this right: that's obviously a hydraulic pump under the alternator, powered off the front of the crankshaft. The rubber hose with the red paint dabbed quick connect goes to a hydraulic assisted steering valve that the steering wheel, coming down at an angle from the left upper corner(round black 5 cm or so in diameter) I see two hoses connected with banjo connections on top of that valve; does one go to power steering and the other to the rear to run the 3 pth ? That hunk of cast iron those 2 banjo connection hook to may be the power steering priority valve. The pump under the alternator looks pretty herky and maybe puts out 8+ gal /min.
The silverish zinc chromate pipe that hooks into hydraulic pump- is that a return ?, if so from where ?, or an out flow ?, to where ? Is that pump devoted to power steering ? Is there another hydraulic pump, perhaps buried in the transmission case the runs the 3 pth and FEL, if you had one ? The nice thing about a devoted power steering pump is no flucuations in flow/pressure as you are using the 3 pth or FEL, if you had one. That's a way to check whether you have a sperate hydraulic pump for the 3 pth is to turn and raise a load on the 3 pth simultaneously- you can feel the flucations in the steering as the 3 pth steals some flow. Tapping into a devoted power steering to run the snow plow will do the same since there is not any excess flow in the devoted steering hydraulic pump.

There may be a 2nd hydraulic pump buried in transmission(the 8+ gallon a minute baby) and a port for tapping into that on the side of the transmission or on the casting housing the 3 pth cylinder on top of the differential right under the seat. Like I said a tractor with a FEL on it would show were to tap into the hydraulic flow for powering hydraulic implements.

Harrygoodwrench · Sep 28, 2003

RCH,
Yes, thats the hydraulic pump that supplies the power steering and other implements. The rubber hose with the quick disconnects is the pressure out of the pump and the metal line is the return back to the resevoir. The disconnects (which I and many others say are not properly located)are there for a factory loader which the loader valve acts as a diverter then sends pressure to the steering. The problem is some guys had the quick disconnect "disconnect" while using the machine and this caused the pump to "dead head" and pump damage occurred. The black device to the left and above the "QD's" (which I put a dab of red paint on) is a diverter with the "banjo" fittings between the pump and the steering control valve.
What Ray and I want to do is eliminate that quick disconnect where it is now, install a diverter/power beyond valve and have everything flow properly then if you did "disconnect" the loader or whatever there wouldn't be the risk of dead head pressureas the power steering valve would still be in the system I guess as a priority valve as you put it.
I am no hydraulic expert by any means and I do appreciate all you are doing for us. Thanks again, Harry G

Harrygoodwrench · Sep 28, 2003

I forgot to add that the "diverter" between the pump and steering control valve also feeds pressure to the 3 point hitch hydraulics.

Rch · Sep 28, 2003

I think you have to tap into that hose that goes to the 3 pth AFTER it leaves the power steering/diverter valve (one of those 2 banjo hoses) in series, i.e. hose goes to new open center valves and the return hose from those valves contiues on to wherever that hose went- conceptly cutting the hose in half and routing the flow through the snow blade valves. I see your concern of a 3/8" constriction slowing the flow to the 3 pth. Maybe you'll need a 1/2" open center valve to preserve the flow to the 3 pth. Here is a link that could help out;
http://www.surpluscenter.com/home.asp?UID=2003021608544039 They got a catalog with various connector that may be necessry with SAE/metric considerations. Another hydraulic gizmo sourcehttp://www.baileynet.com/Intro.asp

By the way, why the 360 degree loop on the hose from the pump ,via the quick disconnect with the dab of red paint to the diverter valve/power steering connection ? I assume there is some movment between the motor and diverter/steering valve because of being mounted to different parts of the tractor. That redpaint dabbed connector looks like it wants to be connected directly to the diverter/steering valve which appears to be mounted to the bell housing /forums/images/graemlins/tongue.gif

Harrygoodwrench · Sep 28, 2003

The reason for the loop in the line with the quick disconnect is that is the way the factory does it. They hook the quick disconnect lines into the loader control,basically in series with the diverter for the steering. That is why I and others say its wrong. If the quick disconnect pops off in the way they have it plumbed then the pump Dead heads.This has happened to other Jinma owners and Ray and I want to avoid this possibility.
Thanks, Harry