CheeMuii DOT brass quick-connect air line fittings 30PCS — CA360 brass, 1/4″·3/8″·1/2″ sizes

CheeMuii 30PCS DOT Brass DOT quick-connect straight unions provide a complete, corrosion-resistant assortment for DOT-compliant air brake and suspension lines.

This kit gathers 30 DOT-style quick-connect straight union fittings in three common bore sizes so you can repair or modify air brake and suspension tubing quickly. Each fitting combines CA360 brass bodies with durable plastic components and meets the DOT/SAE requirements for automotive air systems, making it suited for mobile and workshop applications where reliability and compatibility matter.

What sizes are included and why does that matter?

The set contains ten 1/4" unions, ten 3/8" unions and ten 1/2" unions to cover typical tubing diameters found on trucks, RVs, trailers and many air suspension systems. Having multiple sizes in one kit reduces downtime and ensures you have the right union for the line you’re working on.

• 10 × 1/4" DOT straight unions for smaller control lines
• 10 × 3/8" DOT straight unions for medium service lines
• 10 × 1/2" DOT straight unions for higher flow connections

How durable are these fittings under real-world conditions?

CheeMuii fittings use CA360 brass plus reinforced plastic parts to resist corrosion, tolerate temperature swings, and give long operational life in vehicle environments. They are engineered to the DOT and SAE air-brake guidance so they sustain repeated use and exposure to road and workshop conditions without rapid degradation.

• CA360 brass body resists corrosion from moisture and road salts
• Plastic components designed for impact resistance and reduced leakage
• Meets relevant DOT/SAE standards for air brake fittings

What pressure and temperature ranges do these unions support?

These straight unions function across a wide working window, handling pressures from vacuum up to 500 PSI and temperatures approximately from -30°F to +180°F (-34°C to +82°C). Always verify your tubing manufacturer's ratings and system specifications before installation to confirm safe operating limits.

• Vacuum to 500 PSI working capacity for common air systems
• Temperature tolerance suitable for most on-road and seasonal use
• Follow tubing maker guidance for maximum system stresses

How easy is installation and what applications are ideal?

The DOT quick-connect design is push-to-connect which simplifies fitting replacement and temporary connections during diagnosis or repair. These unions are commonly used in truck and trailer air brake repairs, RV air systems, air suspension hookups, and general fleet or industrial compressed-air lines.

• Push-to-connect action for fast, tool-free assembly in many cases
• Works with copper and approved DOT tubing types
• Useful for trucks, RVs, trailers, towing gear, and workshop air lines

Who is this for? Automotive technicians, fleet maintenance crews, RV owners, and DIY mechanics who need a reliable assortment of DOT-compatible straight union fittings will find this CheeMuii kit convenient. It’s aimed at people who want a ready supply of common sizes, corrosion-resistant construction and DOT/SAE-aligned components to keep air systems sealed and functioning during routine service or emergency repairs.