frt end loader operates slow on 986

Tx Jim

Well-known Member
My neighbor asked me if his 986 utilized an open or closed spool. I told him I knew what open or closed center hyd's were but had no idea what ""open or closed spool"" was. I told him that a 986 had open center hyd's. What is correct method(location) for attaching a FEL open center spool valve without utilizing rear remote breakaways?
Thanks in advance for any replies,Jim
 
AHHH, unfortunately, it gets a little complicated on that model. Early ones were open center, late
ones closed center (pfc) and some have been converted back to gear pump but still using closed
center valves and a unloading valve replacing the priority valve.

Open center system takes flow through oil from aux valves and sends it to the front mcv pump
through what they call supercharge line. When using aux valve (Deere guys call them SCV) that
oil is cut off from super charge line while aux valve is being used so mcv pump pulls oil from filter.

You can tap into that supercharge line and run a set of loader valves but need to return oil from
loader to sump to avoid sending crud to mcv pump. When loader valve is in neutral the oil can be
sent up super charge line to mcv.

If it has pfc hydraulics (probably does not) it is a whole different ball game. Need signal line
and closed center loader valve taking oil before it hits aux valves.

Most just run through aux valve and lock lever because as you can see, it gets messy. Some add
electric selector valve to aux valve outlets so they can switch between sending oil to loader or
just using aux valve for other cylinders as needed.

Confused,yep, gets that way.
 

Pete
I talked to technician attempting to repair my neighbors tractor. You're correct as tech stated this tractor was a pfc hyd type that previous owner attempted to convert to open center by installing a gear pump but didn't correctly change ALL hyd valves. Tech is going to attempt to install some type of conversion kit. I was unaware late model 86 series weren't open center hyd's.

My neighbor recently purchased this tractor with cab & fel for what he considered CHEAP but I think he's going to learn the "hard way"($$$$$$$$$$) the reason it was for sale at a lower than normal price.
Thanks for your reply,Jim
 
(quoted from post at 08:28:21 01/21/20) If he got it cheap enough, the repair is worth it.

BTW, you don't have to change "all" the valves, as in the remote valves.

Couldn't joystick FEL valve have been connected to original hyd system & rear breakaways without any modifications to hyd system? Technician I talked to was going to change a spool valve under cab floorboard. What's the difference in operation of CCLS & PFC hyd's. I once owned a Ford 5610 with CCLS that I sorta understand how it functions.
 
For the conversion to gear pump from pfc, you don't change any of the valves. What you do is
remove the spool for the priority flow valve and replace it with a new spool that acts as a
unloading valve to facilitate the flow of oil back to tank when valves are in neutral.

It requires several different hose connections and a relief valve to replace the safety valve used
with pfc etc , one with an orifice in it for unloader valve to work. Then just hook loader to one
of the aux valve rear outlets and tie lever.

Hy Capacity surely would supply you with a instructions if you asked and sell you any parts to
complete the conversion.

One thing unique about the conversion is you can still regulate the flow similar to the pfc system
with those flow levers.

One has to be careful to check bypass (neutral) pressure to make sure you have everything
installed correctly or overheating and premature wear will occur. Acceptable pressure is in the
instructions and is like 1 or 200 psi in neutral and free flow through like a loader valve.
 

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