ford 7710

[fspring]

a neighbor dropped off his 7710 ford. says its got hyd problems. they changed both pumps and the son told me gotta get the priority valve off which is under the cab.

is there access to the valve by way of a floor panel or does the cab need to be pulled or tipped back???

 

[4500GUY]

(quoted from post at 21:30:50 03/16/22) a neighbor dropped off his 7710 ford. says its got hyd problems. they changed both pumps and the son told me gotta get the priority valve off which is under the cab.

is there access to the valve by way of a floor panel or does the cab need to be pulled or tipped back???

The valve can be reached by removing the cover on the floor, just below the seat.

I had issues with my 7710 as well, but all working now.

 

[Bern]

Changed both pumps. An expensive way to troubleshoot.

 

[fspring]

Exactly what I thought....

 

[fspring]

Thank you. I'm not a Ford guy, but the
sone helps us out part time.. just trying
yo help them out...

 

[jhwis]

what's the difference between the 7700 and the 7710?

 

[4500GUY]

(quoted from post at 19:30:47 03/17/22) what's the difference between the 7700 and the 7710?

The 7710 was released in 1981 and was the newer model after the 7700.

I believe the 7710 is very similar to the 7700 in most respects.

 

[Bern]

10 series has the dual-pump option, and closed center versus open center remotes.

 

[fspring]

ok got this tractor in today. checked flow and pressures on the remotes and it did nothing. i pulled off that priority valve and found metal in the unloading valve. i put it back on just to see if it made i differance. i got about 6 gallons of flow and it topped out at around 700 lbbs pressure, but flow was down to zero at that point. now to figure out what to do next. probably new filters and check each pump to see what they are putting out. probably metal all over the system...... any suggestions would be welcomed....

 

[Bern]

I don't see the point in checking pump output if both pumps were recently replaced. Check the combining/unload spool carefully inside the priority pack to make sure it's not sticking. This same spool has an internal relief valve built into it that could be stuck open because of debris. It can be disassembled and cleaned. Make sure you gauge the depth of the adjusting plug though before you remove it.

 

[fspring]

ok, i cleaned out the relief valve had some small metal in it. took out the strainer, that has metal on it too. owner said the flywheel pump has about 300 hours on it. so they been running it with metal in the system. no change on pressures.. got about 6.5 gallonsflow max, and zero flow at 5-600 lbs. that main rear pump must have been installed before the flywheel pump.

 

[Bern]

If it has significant amounts of metal flowing through the system, it might very well have taken out the new pumps, although one would think that the filters should have caught most of it. Regardless, if I'm working on this rig at the point you're at now, I'd likely flow and pressure test both pumps at this time to make sure they're still good. Testing the engine pump is easy with JIC test adapters, however testing the rear axle pump is a little tougher because it will require a special adapter that plugs directly into the pump.

If the pumps both test good, I'd suspect blown o-rings on the high-pressure transfer tube between the 3-point lift cover and the rear axle housing (#50 & 51 at the link below). Just the very thought of pulling that lift cover off would make for a bad day on a 7710 with a cab.
Tube and o rings

 

[fspring]

Are there any other pressure regulators or relief valves in this system? They say the 3 point hitch does not work either . Also I mis understood. The front pump was replaced. They never changed the rear one.

 

[Bern]

There is a relief valve in the main pump, #3 in the link below. They are not prone to giving trouble.
Relief valve

 

[RodinNS]

If you didn't get this going yet... I would pull the pilot line off the back of the remote and dead head each valve, and in both directions. See what kind of oil shot you get from the back of the valve. Teeing a 3000# gauge in there would be better. Load sense pressure should nearly mirror system pressure for a given load.
Bottom line is... you need strong load sense pressure to get a strong response from the valves, both in terms of flow and pressure. If there are weak or leaking primary shuttles in the valves, the load sense response is bled to sump... and well.. you get what you got. Squat. They have a couple of tiny orifices in there that can plug and o-rings that can leak... So simply but such a nightmare.
Usually the crap gets caught up on the relief ball in the combining valve, but not always. Not saying it isn't the pumps, but very doubtful it ever was.

Rod