Dorman A/C Service Valve Cap

Dorman A/C Service Valve Caps: Small Part, Big Protection

It's easy to overlook an A/C service valve cap — until a missing or damaged one lets refrigerant seep out, contaminants work their way in, and your vehicle's climate control system starts losing performance. A/C service valve caps are the first line of defense for your air conditioning system's high- and low-side service ports, and getting the right replacement matters more than most drivers realize.

Dorman has been engineering aftermarket automotive solutions since 1918, and that century-plus of experience shows even in something as focused as a service valve cap. Since 1918, Dorman has been the automotive aftermarket's pioneering problem solvers, releasing thousands of parts and components that people could once only buy from original equipment manufacturers. That philosophy extends directly to their A/C service valve cap lineup.

OE Solutions Line: Engineered to Match, Built to Last

Dorman's A/C service valve caps fall under their respected OE Solutions line, reflecting a commitment to direct-fit replacement. Each A/C service valve cap is designed to match the fit and function of the original cap on specified applications, and is engineered for reliable performance.

Dorman offers caps in both brass and plastic constructions to suit different vehicle makes, model years, and refrigerant systems. The brass cap (part 902-025) features a threaded attachment type, yellow color, and is compatible with R134a refrigerant systems, with a thread diameter of 0.313 in. On the other side of the spectrum, part 54374 is a practical replacement for damaged, missing, or worn service port caps on R1234yf and R134a systems, with threaded attachment fitting M10 x 7.5 and M8 x 1.0 thread diameters.

Wide Vehicle Coverage

One of Dorman's core strengths is the breadth of its application coverage. The Dorman 54374 fits various model years of vehicles including Alfa Romeo, Buick, Cadillac, Chevrolet, Chrysler, Dodge, Fiat, Ford, GMC, Hummer, Jeep, Lincoln, Mercury, Mitsubishi, Oldsmobile, Pontiac, Ram, and Saturn. Whether you're servicing a late-model Ford F-150 or maintaining an older GM truck, there's a Dorman cap engineered to the correct thread spec for that service port.

Why the Right Cap Matters

Designed to be an exact match for the original equipment part, Dorman's service valve caps ensure a secure seal on specified applications, preventing refrigerant leaks and maintaining system pressure — delivering exceptional durability and reliable performance. A properly seated cap protects the Schrader valve inside the service port from dirt, moisture, and debris that can degrade seals over time and lead to costly refrigerant loss.

Dorman backs these caps with a limited lifetime warranty , reflecting their confidence in the materials and engineering behind even this essential small component. Dorman has built a reputation for engineering parts that meet or exceed OEM specifications , and their A/C service valve caps are no exception — a simple, affordable safeguard that keeps your climate control system sealed and fully functional season after season.