Muzzys Heater Core Coolant Hose Connectors - Set of 2, 3/4" Inlet 5/8" Hose, Upgraded Nylon with Clamps

Muzzys upgraded nylon heater core connectors — a set of two with clamps designed to replace cracked or leaky OEM fittings on many 1998–2014 Chevrolet, GMC and Cadillac models.

If your vehicle is showing coolant leaks at the firewall or you’re replacing a failing heater core, these Muzzys 800-409 connectors provide a direct-fit, reinforced replacement built to resist cracking and heat-related deterioration better than many stock parts. Supplied as a matched pair with two stainless-style clamps, the kit is sized for 3/4" inlets/outlets and 5/8" heater hoses and replaces a range of GM part numbers for a straightforward swap.

How do these connectors improve on the original equipment?

Muzzys engineered these fittings in upgraded nylon that offers higher tensile strength and improved resistance to heat and coolant exposure versus many OEM plastics. That makes them less likely to fracture during removal, installation, or under thermal cycling in older vehicles. They are molded to OEM dimensions so they fit the same firewall tubes and hose sizes for a true direct swap.

• Upgraded nylon composition for better durability and crack resistance.
• Formed to match OEM 3/4" inlet/outlet and 5/8" hose dimensions.
• Includes clamps sized for secure hose retention.
• Replaces multiple GM part numbers for broad compatibility.

Which vehicles and part numbers does this set fit?

This set is made to fit many GM trucks and SUVs produced between 1998 and 2014, including Silverado, Sierra, Tahoe, Suburban, Yukon, Avalanche, Express and Savana lines, plus Cadillac Escalade models. It replaces several commonly referenced OEM numbers so you can cross-check fitment quickly. If your original part number matches one listed, these should be a direct replacement.

• Fits 1998–2014 Chevrolet Silverado, Tahoe, Suburban, Avalanche, Express/Savana, and more.
• Fits 1998–2014 GMC Sierra, Yukon, and larger truck variants.
• Compatible with Cadillac Escalade models in the same years.
• Replaces part numbers: 15032062, 15151873, 15151875, 15792820, 15792821, 15792822, 15834772, 15834773, 800409.

What is involved in installation and what tools help?

Installation is straightforward for anyone comfortable with basic cooling-system work. Removing the old connector is easiest with a heater hose disconnect tool, and the new fitting is designed to be a tight, secure fit on the heater core tube. Use soapy water to ease the new connector onto the tube, push until you hear or feel a secure "click," then fasten the supplied clamp to hold the hose.

• Use a heater hose disconnect tool to remove the old fitting cleanly.
• Clean corrosion and deposits from heater core tubes before installing.
• Apply soapy water to help slide the new connector into place; listen for a "click."
• Secure hose with the included clamp; recheck for leaks after refill and bleed.

Who is this for: This Muzzys connector kit is intended for DIY mechanics, independent shops and fleet maintenance teams working on late‑90s to mid‑2010s GM trucks and SUVs who need a durable, OEM-form replacement for brittle or leaking heater-core fittings. It’s particularly useful for vehicles undergoing heater core service, firewall hose replacement, or coolant leak repair where an upgraded material and included clamps reduce rework and recurrence of leaks.