Servicing Pump Lube Assembly with DOP

In this video, we break down the components of the Pump Lube Assembly for PMC, Gusmer, and Graco machines. The Pump Lube Assembly, or Lube Reservoir, is responsible for preventing moisture from coming in contact the packings. At times, the DOP may become discolored or contain a milky white consistency.

Alternatively, sediments may settle at the bottom of the lube reservoir, indicating that hardener or isocyanates are bypassing the seats of the seal. In these events, it is time to change the fluid with a quality DOP.

How to Replace Fluid in a Pump Lube Assembly

This video gives instructions on how to change the fluid in your Pump Lube Assembly. While your machine is still cool and depressurized, before startup, you should perform a daily inspection of the Lube Reservoir. If discoloration or sediments are discovered, remove the lube reservoir and discard the old DOP – replacing with new DOP.

Clean the Lube Reservoir

Cleaning the bottle thoroughly to ensure any deposits or debris are removed, will help to extend the life of your machine and ensure the check valves are not contaminated when the new liquid is added.

Prime your Pump Lube Assembly

Once you’ve replaced the DOP, depending on the type of machine you have, it may require priming. Slightly tilt the bottle and lightly squeeze. The fluid will start going up the larger line and into the smaller line – letting you know it is primed.


Get the parts you need for this replacement here…
DOP Pump Lube (phone orders only)
SW-5150 (1 gallon)
SW-5152 (5 gallons)

PMC: Lube Bottle Components KT-05004

Graco & Gusmer: Reservoir, Lube Hose Assembly 296731

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John Davidson is the VP of Operations at SprayWorks Equipment Group and is an SPFA PCP Certified Roofing and Insulation Installer, Roofing and Insulation Project Manager, and Supplier Rep. With over 30 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.

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