# Hydraulic issues after new bucket control valve



## Newtooldtractors (8 mo ago)

Hello everyone,
I'm new to tractors but a career auto mechanic and fabricator in need of some advice. I bought a john deere 302a about a month ago and it's been pretty poorly neglected. I had a badly leaking bucket control valve I was having a hard time finding parts for. I ended up finding a 2 way spool valve from magister hydraulics and I retrofitted it in place of the factory valve. The bucket and everything else works great but the gannon only seems to get pressure when operating the bucket. The valve came with no instructions from the manufacturer so I'm not even sure I have the pressure and return lines in the right place. Also, I'm unsure if adjusting the pressure relief will have an effect. I also don't have a hydraulic diagram for the tractor just downloaded an operators manual. From what I can see the loader and gannon are both fed independently from each other. I'm awaiting a response from magister and will resume diagnosis in the am just seeing if I can get some answers from the collective minds before the morning. Thank you all


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## Tx Jim (Jul 28, 2020)

Welcome to the TF
My guess is your new hyd control valve doesn't have a ""closed vcenter conversion plug with inner seal"" installed similar to photo below.. Tractors with closed-center hyd's such as your 302A don't have need for a releif valve in hyd control valve because stroke control valve in frt pump accomplishes similar task. Loader control relief valve should be set to open at 2350 psi or adjusting screw turned completely in. Can you please post photos of your FEL control valve & hose attaching locations on your tractor? What's the Magister valve part #?


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## Newtooldtractors (8 mo ago)

Thank you for the reply Jim. I've attached some pictures and a cut sheet for the valve I have which magister sent me yesterday. The valve is their HCV 2x13. I have it setup with the pressure line going to the p port and the return to the T port as they instructed. Does that plug eliminate the pressure relief valve altogether?


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## Tx Jim (Jul 28, 2020)

Loosen jam nut& turn screw CW until it bottoms out then tighten jam nut. Remove hose in 2nd photo then cap hose fitting.With both control levers in neutral no oil should escape open swivel fitting when engine is operating. Please post photo's of location of where hoses attach to tractor hyd system. Return oil hose should go to ported hyd filter cover.


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## Newtooldtractors (8 mo ago)

Tx Jim said:


> Loosen jam nut& turn screw CW until it bottoms out then tighten jam nut. Remove hose in 2nd photo then cap hose fitting.With both control levers in neutral no oil should escape open swivel fitting when engine is operating. Please post photo's of location of where hoses attach to tractor hyd system. Return oil hose should go to ported hyd filter cover.


The pressure hose is the more dirty of the two pictures. The return in the new hose that attaches to the filter housing.


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## Newtooldtractors (8 mo ago)

So I started it up and had fluid immediately shooting out of the swivel. Going to have some interesting cologne at a graduation this afternoon.


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## Newtooldtractors (8 mo ago)

So I broke down and bought a .pdf version of the repair manual from jensales online. It's a 500+ page read so I'm working on pertinent sections first. My main question is what the loader has to do with gannon operation in the first place? It seems the hydraulic controls for both the loader, gannon, aux cylinders and steering all have independent hydraulic feeds and returns so how does one operating have any effect on another? Would using different fluid change anything? I have no idea what was in it to begin with but I topped it off with 5 gallons of napa tractor transmission/hydraulic fluid which meets the jd spec since I could get my hands on hy-gard.


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## Tx Jim (Jul 28, 2020)

Sorry I should have advised you to only engage starter not start engine. I remember 1st oil bath I recieved at JD dealership while I was assisting a technician diagnose a hyd problem. Not fun getting bathed in hyd oil! The reason you gGannon blade oesn't operate until you move one of your "new hyd control valve levers" is due to oil bath you recieved. 

On closed center hyd control valve oil flow was designed to STOP AT VALVE until a hyd fuction is operated then oil should flow. On your valve oil flows continuosly out FEL control valve return port which is robs supply oil to 3 pt hitch(Gannon blade). Moving FEL valve control lever blocks oil from exiting return port on FEL valve then pressure is sent to 3pt hitch so Gannon blade will then raise.


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## Newtooldtractors (8 mo ago)

Yeah I was really questioning starting it but I shut it off immediately so it wasn't too bad. I got to the section in the manual on the valve detail last night. So the factory valve is a dead end for the fluid until the valve is moved versus the new valve being free flow all the time and only diverts fluid to the cylinders when the valve is moved. Being an auto Trans guy I just wish they had a hydraulic flow chart. If they do I haven't found it yet. My question now is can I keep this valve and operate the tractor without hurting anything. My thought was to put a quarter turn valve on the return side and close it for gannon operation then partial open or fully open for loader operation. Will it hurt the pump running max output for an extended amount of time? I'm thinking it probably isn't good for longevity. Thank you for the help again.


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## Tx Jim (Jul 28, 2020)

Closed center hyd pump moving oil continuosly is against operating design. Did you tighten relief valve to increase opening pressure to above 2350 psi???? Can you remove lower portion of fitting in photo below & post photo of lower portion of this hyd fitting that's hidden in valve housing?


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## LouNY (Dec 15, 2016)

Does the manufacture of your valve mention a closed center conversion plug for that valve.
Most valves did have that as an optional part. You need to convert your valve to closed center operation or replace it.


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## Newtooldtractors (8 mo ago)

Tx Jim said:


> Closed center hyd pump moving oil continuosly is against operating design. Did you tighten relief valve to increase opening pressure to above 2350 psi???? Can you remove lower portion of fitting in photo below & post photo of lower portion of this hyd fitting that's hidden in valve housing?


Yes the prv is as tight as it will go. There isn't anything below that plug. It's a test port for the pressure side. When I had it apart you could see the passage clearly connects to the p port. I just swapped some plugs and fittings around to adapt it from sae thread to pipe. I'm going to look into replacement options but in the interim I may try a shutoff valve on the return. That way I can give the pump a break in between operating the loader. It's not ideal for cycle times but if I was shooting for efficiency I wouldn't have bought a beat up 50 year old tractor. I'll let you know if it works. Thank you again


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## Newtooldtractors (8 mo ago)

LouNY said:


> Does the manufacture of your valve mention a closed center conversion plug for that valve.
> Most valves did have that as an optional part. You need to convert your valve to closed center operation or replace it.


Hey Lou,
I tried calling magister and the guy on the phone had no idea what I was talking about so I'm not entirely sure. I'm going to try emailing them and see where that gets me as that's what he recommended.


LouNY said:


> Does the manufacture of your valve mention a closed center conversion plug for that valve.
> Most valves did have that as an optional part. You need to convert your valve to closed center operation or replace it.


Hey Lou, 
I called magister yesterday and the guy didn't have any clue what I was talking about. I am going to send them an email today since that's what he recommended. Hopefully I can figure out if the have a work around for this valve or another valve with the same or similar footprint.


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## Tx Jim (Jul 28, 2020)

Is this a threaded plug that green arrow points to???? If so a PBY converseion plug could possibly be installed.


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## Newtooldtractors (8 mo ago)

Tx Jim said:


> Is this a threaded plug that green arrow points to???? If so a PBY converseion plug could possibly be installed.


Yes that is a threaded plug. Unfortunately those two ports are tied together internally so both serve as a return. In that cut sheet I sent you the front port I have plugged is the tank port labeled T and the port I have the swivel mounted is N used for what they call continuing power to daisy chain high pressure to other implements. I just chose to use the N port for the return to give some extra space to clear the rops.


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## Tx Jim (Jul 28, 2020)

I think if a closed center conversion plug could be installed in that orifice it would solve your hyd problem. I have forgotten in my old age what the symbols in your valves spec sheet indicate


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## Newtooldtractors (8 mo ago)

It probably doesnt help that these things are made somewhere in eastern europe. I'll keep you posted on what I hear back from magister but I don't see anything close to that on their website so I may have to go another route.


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## Newtooldtractors (8 mo ago)

Update. Magister doesn't make a conversion plug but based on my research there are several other manufacturers that sell what look to be identical valves under different brand names. I was able to find a closed center plug for the summit p40 which is the sae 10 I need and installs in the N port where I could clearly see the valve exit. I tried calling around locally with no luck and just ended up ordering one online that's a week out. I'll get back to Steel work in the meantime and give you an update when I get the plug. If you don't hear back my wife had probably killed me.








Thank you all for the help


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## Newtooldtractors (8 mo ago)

Fixed! While I was doing some mindless jig work on the welding table yesterday I started thinking about that plug I ordered for the summitp40 and how it didn't look long enough to reach the valve exit on my magister valve. So what I did was I pulled the existing Allen plug, removed the oring, jigged it up in the drill press and drilled a hole down the center. I then welded a 8m flange nut on top to accommodate a 8m thru bolt. I squared the edges so I could tighten it with my adjustable wrench then added weld around the nut. I cleaned it up with a flap disc then installed the 8m thru bolt. I found and test fit an appropriate size 8m flange nut to cover the valve exit. I installed a jamb nut on the 8m thru both then installed the flange nut on the other end and welded it in place. Before install I got an appropriate sized hydraulic oring and stuck it into the valve bore with some Trans gel. I then installed the assembly tightened the thru bolt and then the jamb nut. Started it up and operates like it should. No leaks to speak of either. So it's an adjustable sae 10 closed center adapter I guess. Thank you guys for the knowledge. I can only blur the lines between ignorance and stupidity for so long. Lol


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