Product Description
MAHLE C33756 is an OE-style coolant pipe O-ring for the 2017–2020 GM 6.6L Duramax L5P. It restores a reliable seal at the water pump outlet/coolant pipe connection to help prevent leaks and maintain proper cooling system pressure.
- Direct-fit OE-style replacement
- Meets factory specifications for material and dimensions
- Ideal for routine service or leak repair
Fitment
- 2017, 2018, 2019, 2020 Chevrolet/GMC 2500HD & 3500HD with 6.6L Duramax L5P
Cross Reference Numbers
- GM / ACDelco: 12644927
- GTIN/UPC: 639789314482
What’s Included
One (1) MAHLE C33756 coolant pipe O-ring.
FAQ
Will this fit my L5P?
Yes—this O-ring is listed for 2017–2020 GM 6.6L Duramax L5P applications.
Where does it install?
At the water pump outlet/coolant pipe interface on the L5P cooling system.
Do I need sealant?
No sealant is typically required—install the O-ring lubricated with clean coolant; always follow GM service procedures.
Any parts to pair with it?
Consider fresh coolant and inspect adjoining hoses/pipes; replace any worn components while you’re in there.
