Frequently Asked Questions About Mack CX Truck Coolant Reservoirs

Will these coolant reservoirs fit my specific Mack CX model year?

Our coolant reservoirs are designed to fit Mack CX models from 2008-2015. However, there are variations between early and late production years. Early models (2008-2010) typically use a different mounting bracket configuration than later models (2011-2015). Check your existing reservoir's part number or contact us with your VIN to ensure proper fitment. Most reservoirs will have the OEM part number stamped on the bottom or side.

What material are these reservoirs made from, and how long do they typically last?

Most replacement reservoirs are manufactured from high-density polyethylene (HDPE) plastic, which is resistant to coolant chemicals and temperature extremes. Quality aftermarket units typically last 5-7 years under normal operating conditions. Look for reservoirs with UV-resistant materials if your truck spends significant time in direct sunlight. Avoid cheaper polypropylene units as they tend to crack at the mounting points after 2-3 years.

Do I need special tools or experience to install a new coolant reservoir?

Installation typically takes 30-45 minutes and requires basic hand tools including a socket set, pliers, and a drain pan. You'll need to drain approximately 2-3 gallons of coolant before removal. The main challenges are accessing the lower mounting bolts (a wobble extension helps) and properly bleeding air from the system after installation. Make sure to transfer the coolant level sensor from your old reservoir if your replacement doesn't include one.

What's the difference between OEM and aftermarket coolant reservoirs?

OEM reservoirs feature thicker wall construction (typically 4-5mm vs 3-4mm for aftermarket) and come with all mounting hardware and sensors. Quality aftermarket options offer 70-80% of OEM durability at about half the cost. Key differences to check: sensor port threading (some aftermarket use metric threads), cap pressure rating (should be 15-16 PSI), and whether the overflow fitting matches your truck's hose diameter (usually 5/8" or 3/4").

Why is my new reservoir leaking or showing coolant stains after installation?

Common causes include over-tightening the mounting bolts (which can crack the plastic), using the wrong coolant cap pressure rating, or improper sensor installation. Ensure all rubber gaskets and O-rings from your old reservoir are replaced - don't reuse old seals. White residue around the cap area often indicates the system is over-pressurizing due to a faulty radiator cap rather than a reservoir problem. Always pressure test the cooling system after installation to verify proper sealing.