Fix Your Transfer Pump – Before You Replace It

PMC GHO, IPM OP series, Graco T2 Transfer Air motor performance

Rebuilding the entire transfer pump can get expensive and may not be required. After much use, the transfer pump air motor starts operating sluggish and leaks air. This is generally due to deforming (wear) of the upper reversing spring and the upper air valve gasket. The spring shows this wear generally in two ways. The first being the pump fails to return to the down stroke and secondly the pump will pause momentarily when reversing to the down stroke which appears as a cavitation type action. Changing the spring is the best solution, but when in a pinch, stretching the spring to its near original length can get you through the day.

The upper air valve gasket is pressed between two plates and is smashed every time the pump reverses. Wear of this seal is noticed by the slight to severe leaking that starts when the pump is in the stall position or when stroking down. To replace the upper air valve while the pump is in the drum, remove the air cap and cylinder, then loosen the three allen screws. Before completely removing the allen screws, wedge a rag or paper between the lower plate and the air piston housing. This will ensure the holes and tubes remain in position when the screws are removed. Lift off the upper air plate and the seal is located under the plate. Flip the plate over in a pinch or replace if available.

Recommended Spare Parts

SPRINGUPPER VALVE GASKET
IPM OP series500005500015
PMC GHOPU-04000-72PU-04000-15
Graco T215763015J539

*Call 330-587-41411 to order the above parts.

Remove Upper Reversing Spring from Air Cap

STEP 1: Remove Upper Reversing Spring from Air Cap

 

 

 

 

 

 

 

STEP 2: Slightly loosen the Allen Screws (do not remove the screws)

STEP 2: Slightly loosen the Allen Screws (do not remove the screws)

 

 

 

 

 

 

 

 

 

 

STEP 3: Wedge a rag or paper between the Lower Plate and Air Piston Housing

STEP 3: Wedge a rag or paper between the Lower Plate and Air Piston Housing

 

 

 

 

 

 

 

 

 

 

STEP 4: Location of Upper Air Valve

STEP 4: Location of Upper Air Valve

 

Posted in Tips from the Experts, Transfer Pump and tagged , .
John Davidson

John Davidson

John Davidson is the VP of Operations at SprayWorks Equipment Group and is an SPFA PCP Certified Roofing and Insulation Installer. With over 25 years of experience in the spray foam and polyurea industry, John brings a wealth of knowledge and hands-on experience. He has worked on commercial and residential buildings, bridges and infrastructure.