All Parts Radiators Charge Air Coolers A/C Compressors A/C Condensers Evaporators A/C Dryers A/C Lines Coolant Tanks Expansion Valves A/C Switches O-Rings

O-Rings and Seals

O-ring seal kits for A/C system connections prevent refrigerant leaks and maintain system pressure. Replace whenever any A/C component is removed.

-
Parts Listed
-
Makes Covered
Semi truck A/C O-ring and seal kit on shop workbench showing multiple sizes — replacement for Class 8 heavy-duty truck air conditioning fittings

Filter by Vehicle

Part # Makes Years

Have a part number? Know your truck?

Use the filter above or give us a call.

📞 (437) 868-4875

Semi Truck A/C O-Rings & Seal Kits — Refrigerant Leak Repair Parts

A/C O-rings and seals are the most overlooked cause of refrigerant leaks on semi trucks. Every connection in the A/C system — compressor fittings, condenser connections, line couplings, service valves — uses O-rings to seal refrigerant under pressure. Over time, these rubber O-rings harden, crack, and develop micro-leaks. Replacing O-rings when servicing A/C components is inexpensive insurance against refrigerant loss and compressor damage.

At True Truck Parts, we carry OEM-spec A/C O-ring and seal kits for major semi truck makes. Serving fleets in Mississauga, Brampton, Vaughan, Milton, Oakville, Burlington, and across the GTA. Always replace O-rings when disconnecting any A/C fitting. Same-day quoting, Canada-wide delivery.

Frequently Asked Questions — A/C O-Rings & Seals

How do I find an A/C refrigerant leak from O-rings on a semi truck?

Use UV leak detection dye in the system — add dye, run the A/C for 10–15 minutes, then inspect all fittings and connections with a UV light. Any oily residue at fittings is a sign of O-ring failure even without dye. An electronic refrigerant leak detector can also pinpoint small leaks at individual O-ring connections.

Should you replace O-rings when changing A/C components?

Always. Any time you disconnect an A/C fitting — compressor, condenser, dryer, expansion valve, or line — replace the O-ring before reassembling. O-rings are inexpensive, and reusing old O-rings after disconnection almost always results in a leak. Use the correct O-ring size and lubricate lightly with refrigerant-compatible oil before installation.

What type of O-rings are used in semi truck A/C systems?

Most modern semi trucks using R-134a refrigerant use green HNBR (Hydrogenated Nitrile Butadiene Rubber) O-rings, compatible with PAG oil. Older systems using R-12 used neoprene O-rings. For systems using R-1234yf refrigerant, specific fluoroelastomer (FKM) O-rings are required. Using the wrong material causes premature O-ring failure and refrigerant leaks.

Get a Quote for Your Truck

Enter your truck details and last 9 VIN digits — we'll call you back with the right part and price.

Found on door jamb or dashboard.

No spam. We only call with your part information.