Hello. Long time lurker, first time poster here. I have a question about substituting Mobil 424 hydraulic oil for NAPA hydraulic oil (NHF85401 “Premium Heavy Duty Tractor Hydraulic and Transmission Fluid”). I have found the Mobil 424 to be rather hard to come by and quite expensive. I am trying to find an oil compatible with a Peerless 2000 series hydrostatic transaxle. The manufacturer specifies Mobil 424 for the hydrostatic unit (which is a variable displacement rotary piston pump ).
While attempting to cross-reference, I have determined that both the Mobil 424 and the NAPA 85401 oils are API GL-4 and John Deere J20C compliant. I have tried to determine if the ISO or SAE weights are the same or similar, but haven’t been able to find this information.
So in the end, my question is this: Are there any thoughts as to whether the NAPA 85401 H/D hydraulic oil is a suitable replacment for the Mobil 424 in my application?
Possibly worth mentioning, this is for a riding mower located in Cleveland, OH where it may be subjected to cold starts and operation, and definitely will be used for mowing in the heat of the summer. The owner complained that the mower would work for about 10 minutes or so until it would begin to lose power even up the slightest of grades. The transaxle itself was caked with grass which inhibited cooling, and I suspect broke down the integrity of the oil and/or damaged the pump or motor. I want to try replacing the fluid first before attempting further repair.
While attempting to cross-reference, I have determined that both the Mobil 424 and the NAPA 85401 oils are API GL-4 and John Deere J20C compliant. I have tried to determine if the ISO or SAE weights are the same or similar, but haven’t been able to find this information.
So in the end, my question is this: Are there any thoughts as to whether the NAPA 85401 H/D hydraulic oil is a suitable replacment for the Mobil 424 in my application?
Possibly worth mentioning, this is for a riding mower located in Cleveland, OH where it may be subjected to cold starts and operation, and definitely will be used for mowing in the heat of the summer. The owner complained that the mower would work for about 10 minutes or so until it would begin to lose power even up the slightest of grades. The transaxle itself was caked with grass which inhibited cooling, and I suspect broke down the integrity of the oil and/or damaged the pump or motor. I want to try replacing the fluid first before attempting further repair.