My hydraulic pump is making a buzzing noise, and when I put my hand on the pump case while running it feels as if I can feel a vibration. Also when I move the blade it gets louder. The more pressure on the blade lever the louder it is. It seems to dissipate with the warming up of the engine. I don't understand how the fluid path is from my manuel. It states that the transmission fluid flows from tank to magnetic strainer, to filter, then to clutches etc. I don't know where the fluid in the hydraulic tank at my right goes. Is the pump a 2 cavity pump, or is the fluid mixed in the trans and hydro tank. The machine is power shift, and seems to operate properly. It is a recent purchase, from a reputable guy, and had all fluids changed,w/ screens checked and filters changed. My first guess was a bypass valve from cold fluid causing the noise, however I don't want to ruin something in case it is cavitation, or something else with the pump itself. I did ask the PO what fluid was in the unit and he said cat 30 wt oil. I was under the impression that the hydraulic tank for the blade was a lighter oil. My manual states hydraulic fluid here and 30 weight in the transmission, and 50 weight in the finals but I am told that 30 wt in these old machines is OK as there might be some leakage into the trans from the clutch pacs. Any ideas ?? thanks in advance and happy turkey day. rick
Sure it is a D7E? Whats your serial?
Prob an old D7E, not the new D7E's
ser is 48A 11383, it is one of the old ones.
Bypass would be my guess. Straight 30 wt. is a little heavy for cold weather I would think, I always ran 10wt in my 8K's
I think I will drain and refill the thinner hydro fluid and see if this helps. Would this make the clutch release a bit sluggish? I notice the release gets better as it warms up.
Not sure what you mean, how would a hydraulic oil change affect the trans? they are seperate
As I understand it, the hydraulic pump uses hydraulic fluid (could be wrong) to disengage the clutches packs. Where does this fluid come from? The tank to my right or from the transmission sump? That is why I wondered if the "pump" is actually a duel cavity pump which pumps both transmission fluid , and also hydraulic fluid for the blade. As you can see I am not very clear on the fluid flows.
I am not familiar with these machines but I would check the suction hoses for deterioration . They can suck flat and hammer and also suck air and cause cavitation .
Thanks- You all have given me some things to check. I plan to feast and watch a bit of football. I have a family that is combined texas aggies, and university of texas grads , which makes this holiday a fun one.The game between them is always interesting.rick
If it is an older "E" 30 wt will be fine for the tranny. I ran into this with a loader and a 7E. Both were a suction problem on the charge system for the converter not the hyd pump. The first thing I would try is changing the suction line from the tranny and the "O" rings at the fitting ends. It is usually just the "O" ring but the suction hose can suck air in and not leak oil and fool you. The "E" we had problems with someone had lost the "O" ring at the tranny end and just made a gasket it took a while to figure it out.
Guess I'm lost, thought we were on the hydraulic system buzzing.
The blade and transmission have completley separate systems, independant of each other.
the transmission and steering clutches are on a common system. The blade operates out of a separate system. Oil for that system comes from the tank which is to the right of the operators seat. Sounds like maybe there is wear in the pump which operates the blade. This could be as simple as the bushings in the pump.
makes more sense, thanks