Frequently Asked Questions About International 9300/9370 Heat & AC Parts
Will these heater cores and AC components fit my specific International 9300 or 9370 model year?
Most heat and AC parts for International 9300 and 9370 models are compatible across years 1987-2003, but there are important variations. Early models (1987-1994) often use different heater core dimensions and mounting brackets than later models (1995-2003). Always verify your OEM and check if your truck has the standard HVAC system or the optional heavy-duty climate control package, as this affects part compatibility. When ordering, have your truck's model year, OEM, and current part numbers ready to ensure proper fitment.
What are the most common signs that my heater core needs replacement, and how difficult is the installation?
Key indicators include sweet coolant smell in the cab, foggy windshield that won't clear, wet passenger floor mat, or low coolant levels without visible leaks. Heater core replacement typically requires 4-6 hours of labor and involves removing the entire HVAC box from under the dash. You'll need to drain the cooling system, disconnect heater hoses from the firewall, remove the glove box and lower dash panels, and carefully extract the HVAC housing. Having a second person helps significantly when maneuvering the box out. Most mechanics rate this job as moderately difficult due to tight spaces and multiple electrical connections.
Are aftermarket AC compressors and condensers as reliable as OEM parts for these trucks?
Quality aftermarket AC components from established manufacturers like Sanden, Denso, and Four Seasons typically match OEM performance and often carry similar warranties. The key is ensuring you get the correct compressor type - most 9300/9370 models use either Sanden SD7H15 or SD709 compressors. Aftermarket condensers should match OEM specifications for cooling capacity (BTU rating) and physical dimensions. Many drivers report good results with aftermarket parts when properly installed with new O-rings, proper oil charge, and correct refrigerant amount.
What's included in a complete HVAC repair kit, and what additional parts might I need?
Complete HVAC kits typically include the heater core, evaporator core, expansion valve, and basic mounting hardware. However, you'll likely need additional items not included: heater hoses (5/8" and 3/4" diameter), fresh coolant, AC O-ring kit, refrigerant oil, foam insulation tape for the evaporator housing, and new cabin air filter if equipped. Many technicians also recommend replacing the blower motor resistor and temperature control cable while the dash is apart, as these commonly fail and are difficult to access later.
How can I identify which blower motor assembly I need - are there different styles?
International 9300/9370 trucks use two main blower motor configurations: single-wheel and dual-wheel assemblies. Single-wheel units are more common in base models and sleeper cabs, while dual-wheel setups are found in trucks with rear sleeper HVAC systems. Check your motor's amp rating on the label - standard motors draw 15-20 amps, while heavy-duty versions pull 25-30 amps. The mounting cage style also varies - some use a 3-bolt pattern while others have a 4-bolt configuration. Measure your existing motor's diameter and shaft length before ordering, as even same-year trucks might have different specifications based on HVAC options.
