Here is my take. The hydraulic pumps are super powerful, however it comes down to difficulty of repacking the leathers and availability of parts. With an air diaphragm, you can get parts or pumps nearly everywhere. Ive seen guys with hydraulic pumps dead in the water waiting for parts. As far as power, like I said hydro pumps are powerful, and will move any sand load with ease, but so can diaphragm pumps, you just need the right size of pump. If you went to a 2 pump, you'll see the power. As far as surging, if you have the right setup, that too can be prevented. Most common its seen in undersized surge bottles and shorter hoses being the problem. We have a Seal-Rite 700 with a 2 pump and it is super powerful. We run an 8 tip spray bar with ease all season. I personally would go with a diaphragm just for parts convenience.

Our 700 is still going strong at 3 years old. We intend to repack the pump this winter for the intention of making a video on how to do it, but if it weren’t for that, no reason it’s running great. We have a 2010 Equipt and it’s still running strong, no issues. We also have a 2” wilden on our buggy, and it is 5 years, and strong, I think the key is keeping the air dry, but honestly they are workhorse pumps. It may not be a fair comparison, those piston pumps are also super heavy duty...it just came down to parts. If I lose a pump, I can almost certainly find one locally.

Asphaltman, How often do you have to service your Seal Rite 700 Pump? I have the same pump on my Seal Rite 550. I have had it for two seasons now and am wondering when to expect some maintenance on it.