We had three separate P40 pumps crack in the exact same spot in one day of 35° weather. One brand new, one a few months old, one after its first job. Different trailers, same failure point above the inlet tube on the new-style manifold.
Comet will not warranty cold weather failures. They made that clear. These are reinforced plastic pumps originally designed for pest control — not the same as traditional pressure washer pumps. When pressure has nowhere to go, it finds the weakest point.
Common causes that lead to cracks:
- Running full RPM
- Cranking the regulator for maximum pressure
- Staying off the trigger too long
- Cold temperatures (wind chill matters)
If you see a leak — stop immediately and fix it. Soft wash systems can and will freeze. Blow out lines, run antifreeze, or shut down when it gets too cold.
How to replace the manifold/collector:
Tools needed:
- 1/2" socket
- Torque wrench
- #6 Allen wrench
Steps:
- Relieve all pressure from the system.
- Remove the bypass/unloader assembly.
- Remove the bolts holding the collector.
- Note the different lengths: longer bolts go on the outside, shorter ones in the middle. Keep them organized.
- Lift the old collector off. Check that the seats and O-rings came with it.
- Lightly grease the O-rings on the new manifold for a clean seal.
- Align the new collector carefully and hand-thread the bolts.
- Tighten in a cross/star pattern.
- Torque in two stages:
- First to 8 Newton meters
- Final torque to 11 Newton meters
- Reinstall the bypass assembly with the Allen bolts.
Take your time on the torque sequence. These are plastic threads — overtightening or uneven tightening will create new problems.
Full video walkthrough: https://youtu.be/RkYfQfz0R2Y
P40s can be solid tools when treated correctly, but they have limits. Know them before the cold weather (or a closed valve) teaches you the expensive way.