Combines 7720 hydraulic noise

ARE YOU STEERING WHEN THE NOISE OCCURSIJ IT IS HYDRAUlIC AND NOT HYDROSTATIC, YES. MAKE SURE YOUR UNlOADING SWING lEVER IS NOT HANGING UP IN THE VAlVE. THIS CAUSES NOISE AND HEATING OF THE OIl. CHECK IT. lET ME KNOW

The noise does not appear to be related to the steering or auger hydraulics. I am a bit suspicious of the steel hyd. lines that are mounted under the cab. I changed one steel line to rubber and there was a definite improvement. A hand placed on the steel lines feels a very high frequency vibration, which is why I suspect the steel lines.

MAKE SURE THE TWO lINES THAT FEED THE REEl ARE EITHER CONNECTED TO EACH OTHER, AS IN WITH A CORN HEAD, OR THEY ARE CONNECTED TO THE FlEX HEAD. THIS ASSUMPTION BEING THAT YOUR NOISE IS ONlY WITH THE SEPARATOR ENGAGED. AlSO, UNDER YOUR FEET, THE VAlVE THAT CONTROlS THE HEADER HEIGHT HAS SOME SMAll POPPETS THAT ARE SEAl WITH A TEFlON RING, THEY DO WEAR OUT, CAUSING A FREQUENT THUMPING NOISE, WHICH IS THE HEADER BOUNCING, AND AlSO A WHINE, WHICH IS BYPASSING OIl. THE POPPETS ARE A BREEZE TO CHANGE, BUT GET READY TO GET FUll OF OIl. lET ME KNOWIJIJ

Poppets were OK. I replaced the steel pipe to the main spool valves and the steel bypass from there to the secondary spool valves, with rubber hyd hose. It has made a big difference