Your cart is empty
Browse our catalog to find the parts you need.
These images are illustrative and may not match the product exactly. Always verify by part number — or confirm instantly with the assistant using a photo or VIN.
Meritor · Air System
3218401A
In stock · ships from Knoxville
This Meritor genuine press plug kit seals the open end of a 2.75-inch axle tube on Meritor and Hendrickson axles that use a central tire inflation system (CTIS).
Confirm the part fits before you buy. Applications and interchange numbers are researched and audited per part.
Verified fitment for 7 applications
Add your truck to see whether it's one of them
All confirmed applications for this part number.
Other applications
Other applications
Requires a 2.75-inch axle tube end. Kit includes adhesive and O-ring. Used with Meritor Tire Inflation Systems (MTIS). Not for Dana P22 or pre‑2002 Hendrickson HP axles.
Part data verified against 5 catalog sources
Numbers this part supersedes or interchanges with. Showing 2 of 2.
Different year, make, or config? Get a confirmation against your truck in under a minute.
It provides an airtight plug to maintain proper air pressure in the axle tube, which feeds air to the tire valves. The kit includes a press plug, O-ring, and adhesive for a secure, leak‑free installation. It is typically replaced when the original plug begins to leak, causing a slow loss of tire pressure, or during axle rebuilds and CTIS service.
Part Number: 3218401A
PSI PRESS PLUG KIT
Unit: ea
Dealer: Knox Trailers
Compatibility, alternatives, and more
Parts commonly needed alongside air system
