Can't figure out Model 70 hydraulics

John Deere suggests that one or both of the plugs (in the rear) should be solid when using the rock shaft. One of mine is open and the other one is metered (I have it closed at the moment). Reversing these plugs just locks up the system, entirely.

Anybody seen this setup? It was fairly common around here 40 years ago. All the old timers have gone on and I�m up against more that I can figure out. Any help would sure be welcome.

Thanks ahead.

Putt Putt

I don't think you'll find anything on the use of this "special plug" in any Deere operating manual because I don't believe the "special plug" was a Deere part! Many dealers sold them but I think they were an after market part. By using this plug & taking oil from the pipe plugs out the side, you could install a quick attach type (like Pioneer) couplers that stopped oil loss when the drawn implement (usually a plow) un-hitched after hitting a rock or roots. With the Deere original system, you only had enough oil to endure two drops. So much oil is lost when the hoses pull out (from both the tractor & the plow cylinder) that if you un-hitched a third time you ususally did not have enough oil left to raise the plow when you got to the end of the furrow. It was not ideal but it saved keeping an oil jug on the platform if plowing rocky ground. BTDT!

Adjust your throttle and drop valves according to the book. Hope this helps.

Later.

Dual valves used to be the "standard" also, but now most new tractors are at least offered with up to four! When "Hydraulic Powrtrol" was standard, everyone used drawn equipment. After the three point hitch became the new "standard" in the mid 50s, semi-integral equipment was developed and became available for it. This was probably a major reason why some farmers traded up from a "70" to a "720" so quickly. It was also a reason why a "70" was not as desireable as a "720" or a "730" on the used market during the 1960s. It didn't have the new type hydraulics.