It should be making the same sound going up and down. I just sold my Volvo DP and it sounded same up and down. I would rather not buy a new pump. I would like it to operate correctly. I wonder if there is something in the pump and needs to be drained? I just bought it not long ago. So I don't know the history of it.
Nope,.... Not really,.... When goin' Up, 'n the pump hits it's limit, it crowds the pump, stallin' the motor,....
That's the Hi-pressure side,.....
The low-pressure side, the Down stroke, when it hit's it's limit, or is near it's limit, will unload, 'n whine like yer hearin',....
You can check the fluid for water,... If it's creamy, change it,....
I'd sooner think yer hearin' it start to unload because of,....
A,... the pivots need more grease,....
Or,...
B,.... The glands are gettin' built up crud, causin' the rods to drag in the gland nuts,....
I agree with ya, that the excess screamin' should only be heard when the drive hits Full Down,....
