Pump stack is leaking.
There are several areas to look at if a pump stack appears to be leaking. The first step is to verify that there actually is a fluid leak. Sometimes fluid spilled onto the top of the enclosure while refilling the reservoir can slowly drip down the pump stack and leave fluid in the bottom of the enclosure and give the appearance that it originated at the pump stack. Begin, by cleaning the pump stack from top to bottom as well as the enclosure.
A leak between two pumps or a pump and a manifold block is often incorrectly diagnosed and is extremely rare. Fluid can collect in the seam between two blocks and it can be very difficult to clean all of the fluid out without disassembling the pump stack. It may look like the source of the leak, but it often originates elsewhere.
Fluid spraying from the breather on an MV pump is relatively easy to observe as the breather is located on the front of the pump and is visible while the pump is assembled inside of an enclosure. The breather on a standard pump is located on the back of the pump and usually cannot be seen if the pump is installed in an enclosure. This type of leak is often observed as fluid in the bottom of the reservoir and a trail of fluid down the bracket that the pump stack mounts to. To properly diagnose a pump breather leak on a standard pump, the pump stack may have to be removed from its mounting bracket and the pump(s) cycled while observing the breather port for signs of fluid.
Fluid spraying from a breather port on a pump will normally spray out of the breather as a fine mist and may take multiple pump strokes before enough fluid gathers on/in the pump. If there is water or oil in the pressurized air supply then fluid spraying from the breather doesn’t necessarily indicate a problem with the pump. However, if fluid from the reservoir sprays from the breather port there may be an internal pump seal issue that must be addressed.
