Hydraulics question

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