Hello, I have a Case SR200 that works great, until I hook up my CAT snowblower and get into heavy snow. As soon as she loads up pretty good I lose fan speed on the blower and I can hear oil being diverted down by the valve body. Any idea where? Is there a specific relief valve for the auxillary circuit or would it be the acutal solenoid valve for the auxillary? Any help would be appreciated, all the shops are at least two weeks out from being able to flow test and tell me where my issue it. Case SR200 Mechanical hand controls and EH auxillary
sounds like the snowblower is not match well to the machine. There's probably an internal relief valve in the control block on the blower. Do you know the flow of the machine and the size of the motor on the snowblower?
Don't believe that is the issue. Snowblower worked fine before and I can hear oil being bypassed underneath the operator's seat when it starts acting up. The snowblower is rated for optimal flow of 21.1 gpm and my machine is rated at 22 gpm. Thanks for initiating some discussion on this.
My mistake, for some reason I thought this was a new blower. If it worked before, then it should work now too. I'd start by looking at the hydraulic control block on the blower. I'm fairly sure there is a bypass valve in there, so the aux flow will bypass if the blower gets jammed with snow/ice. I'm guessing that valve might be partially stuck open. If you can figure out which one it is, try pulling it and cleaning it.
The blower was brand new last year, used I think three times. Hooked it up this year and it works find until you get in heavy snow and then I can first hear the oil bypassing below me through the control valve and then you can see the fan on the blower slow down and the snow starts building up and pushing in front of it. I don't believe it is related to the blower. As soon as you either slow down your speed or back up the oil bypassing sound goes away and the fan speeds back up and clears the blower. I would think if it was on the blower I wouldn't be able to hear anything as the oil would just be running straight back through the return line to the skid steer. I just ordered some fittings and I am making a pressure testing hose that I will put in line in the supply hose to the blower. That will allow me to see if I am losing pressure when the snowblower slows down.
Yeah, I got what you are say now. Pressure test will hopefully tell you something. Sounds like you're on the right track now.
Curious, what type and model of blower did you buy? It does sound like a flow issue to me also.
To me it sounds like maybe the pressure relief is not correctly set. Loading up the blower will require more pressure to drive it (pressure is a factor of resistance to flow). You mentioned you can hear it running over relief so its a good place to start. In my experience, 9 times out of 10 when an attachment is not functioning correctly its because the machine itself is not properly set up. My first point of attack is always to get a flow meter on the machine to find out if its producing what's required for the attachment.
What pressure is the snowblower designed for? GPM is only 1 part of the equation. Also what kind of snow? Packed driven on snow with some ice can be hard for all but the heaviest duty blowers.