By now we’re sure that you’ve all heard of a piston pump. The piston-style pump has been around for years and was the industry’s best-kept secret until they allowed it at our hydraulic competition a few years back. The first versions of this style pump were crude because the home-made designs had to be concealed in the 18-gauge oil tank. Once the hydraulic judges realized that safety was being compromised, the ban was lifted to allow the industry to grow and reinvent itself.

This style of gate pump could be compared to a supercharger because it uses force air feed technology to feed fluid to the hydraulic pump head. For all you drinkers, it’s like drinking a beer through a beer funnel or beer bong. With air or nitrogen in the system it could be considered a dangerous pump–and nobody has ever wanted to do an article on the gate pump. With that said, we caught up with the team at AH-2 in Santa Fe Springs, California, who were going to change out a blown pump head on a piston-style pump. We took advantage of the situation to document the teardown and hopefully give you some safety pointers to help avoid any mishaps.

Some of the advantages of owning a single-piston pump is that they create the same amount of pressure as two traditional pumps to the front of any car. This will eliminate wasted space in the trunk and allow you to fill it with more batteries since some of these pumps need more power to make them work properly. The average setup consists of six batteries. Piston-equipped setups require a minimum of eight batteries to allow the pump to spin properly.

One of the downsides of having a piston-style pump is the fact that you need to be careful because it could be compared to carrying a nitrogen bottle in your trunk. Since the piston pump’s been made public, we’ve heard stories of guys trying to tear down pumps on the car, and the tanks or the piston shoots into the quarter panels of the car because they forgot to release the air pressure. Even though there is no specific amount of air that is recommended, most people don’t run more than 100 psi of air pressure in their tank. There have been rumors of some people running tanks with 300 psi in them–this is not recommended–which is like a ticking time bomb waiting to go off. If a piston can take out a quarter panel with its force, just imagine what it will do to a human.

Follow along as we show you some of the dos and don’ts when working on a piston-style pump, as the men over at AH-2 show us how to replace the pump head on this style hydraulic pump.