Motorad T178 Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap for Honda and Acura

The Motorad Standard T178 engine coolant reservoir cap is a threaded replacement cap built to meet OEM specifications for cooling system service. It is designed for the Honda Pilot and Acura RLX applications listed below, with a white plastic construction and the correct relief and vacuum valve setup for standard reservoir use.

Motorad’s Standard line focuses on direct-fit cooling system service parts that match OE requirements for everyday repair work. The T178 is a standard-style coolant reservoir cap for open and closed coolant recovery systems.

Key Features

• Fits 2014-2015 Acura RLX, N/A
• Fits 2009-2015 Honda Pilot, N/A
• Threaded attachment for secure reservoir fitment
• Plastic construction with round, white design
• Standard cap type for open and closed coolant recovery systems
• Built with proper relief and vacuum valves
• Filler neck inside diameter: 1.22 in; outside diameter: 1.34 in
• Motorad part number T178

Detailed Description

The Motorad T178 engine coolant reservoir cap is made for drivers and technicians replacing a worn or damaged coolant tank cap on select Honda and Acura vehicles. It is a standard, threaded cap with a round profile and plastic body, sized for a 1.22 in filler neck inside diameter and a 1.34 in filler neck outside diameter. This part number is also referenced as Gates T178 and cross-references 703-1971 and 19102RN0A00 for the same application.

Use this cap when servicing a 2009-2015 Honda Pilot or a 2014-2015 Acura RLX that calls for the listed reservoir cap specification. The Motorad Standard T178 helps maintain proper coolant recovery system function by using the correct relief and vacuum valve design for OE-style cooling system service.

What It Helps Address

• Cracked or worn coolant reservoir cap
• Loss of proper reservoir sealing
• Incorrect pressure or vacuum control at the cap
• Coolant overflow or recovery system irregularities
• Service replacement for a damaged threaded cap

Installation Notes and Tips

Confirm the filler neck dimensions before installation and match the cap to the vehicle’s coolant recovery system type. Install the cap by threading it on until it seats securely, and inspect the reservoir neck and sealing surfaces for damage before reuse. For fitment, this part is listed for 2014-2015 Acura RLX and 2009-2015 Honda Pilot applications.

Quality Assurance

Motorad manufactures this Standard coolant reservoir cap to meet OEM specifications and quality tests it for use in demanding automotive cooling systems. The cap is built from high-quality components and is designed for consistent relief and vacuum valve operation.