My MH 44 has a 6.3 GPM capacity hydraulic pump (if in good shape), I used a 3 GPM priority valve for the steering. It steers real crappy at low RPMs, so I did the math.
The pump gear turns at 110% of the tractor RPMs. The tractor must be running 725 RPM before the minimum supply flow for the steering is met. I would be concerned if running a priority valve on an older tractor with low flows, like I did.
I looked into upgrading pumps, and have some info from that. I am lucky, the pump on my MH is a standard SAE A flange, so it is easily replaced. The current pump calculates out to .975 cu. per revolution. Pumps are sold by the cu in per revolution. I found a prince pump for about $200 that fits the flange and will supply 10.5 GPM, or about the same output as my tractor before the power steering was added. I can bore the old gear out to match this, press it on and good to go.
Bottom line, I think an engine driven power steering pump is best option on older tractor.
The pump gear turns at 110% of the tractor RPMs. The tractor must be running 725 RPM before the minimum supply flow for the steering is met. I would be concerned if running a priority valve on an older tractor with low flows, like I did.
I looked into upgrading pumps, and have some info from that. I am lucky, the pump on my MH is a standard SAE A flange, so it is easily replaced. The current pump calculates out to .975 cu. per revolution. Pumps are sold by the cu in per revolution. I found a prince pump for about $200 that fits the flange and will supply 10.5 GPM, or about the same output as my tractor before the power steering was added. I can bore the old gear out to match this, press it on and good to go.
Bottom line, I think an engine driven power steering pump is best option on older tractor.
