The cooling system on your Fox Body Mustang is extremely critical to maintaining its performance and longevity. With the Fox Body being 20+ years old, the factory components (if they are still in place) have seen their best days and should be replaced. We get a lot of questions about what cooling modifications are needed and when. Hopefully I will help get rid of some of the cooling system myths and legends within this article!
The following inspections and replacements should be done before ever moving onto major upgrades such as larger radiators, high flow water pump and electric fans. If these basic inspections and replacement parts aren’t taken care of in the beginning then those major upgrades will provide you will little or no gain!
STEP 1 – Coolant Flush: Step one is the easy one. Check your parking spot and look for coolant on the ground. Take a flashlight and inspect the radiator, hoses and engine block for coolant leaks. If you have a leak it is time to fix it. If you don’t find any leaks, inspect the coolant and see what condition it is in. If it is rust brown color it is time for a flush and fill. Try using some Purple Ice cooling system additive from Royal Purple to improve your coolants cooling ability. It also provides your with corrosion resistance above and beyond what is in your coolant as an added bonus!
STEP 2 – Radiator Hoses: Radiator Hoses tend to swell and wear out over time. Replacing these every 75,000-100,000 miles will help you avoid a ruptured hose. Splitting a radiator hose on your Fox Body Mustang always seems to happen at the worst possible time in my experience – at the race track or in traffic. Here at Late Model Restoration we carry a complete line of performance and factory replacement hoses for your Fox Body!
STEP 3 – Air Deflectors: The radiator air deflectors are often overlooked when it comes to Fox Body coolant system restoration. The lower air deflector is often torn off on speed bumps or curbs. The side air deflectors are often left off during radiator replacements or when replacing core supports. The radiator air deflectors are critical in helping force cool air through your radiator rather than around it. Check out our installation video below!
STEP 4 – Fans & Clutch: Broken radiator fans or worn out fan clutches can result in improper cooling. Broken or cracked fan blades not only lower your cooling ability but if they break under speed they can cause damage to your engine components. When your Mustang fan clutch fails normally it will stop engaging and will allow the fan to spin freely. This will cause your engine to overheat and for your air conditioning to stop cooling as well. Though not as common another symptom of fan clutch failure is when the fan clutch is locked up or always 100% engaged. If this happens during the winter months the heater will blow lukewarm air instead of hot air.
STEP 5 – Fan Shroud: This is yet another easy step. Make sure the cooling fan shroud is not missing or broken. The fan shroud helps funnel air and improves the efficiency of your fan and fan clutch assembly. If you are noticing any marks from the fan dragging, you should inspect your motor mounts. Severely worn motor mounts can cause the motor and cooling fan to drop onto the shroud.
Ensuring the 5 previous steps are followed will leave you with a solid cooling system that will handle any lightly modded Fox Body Mustang. If you are like most other Mustang enthusiasts out there, you can’t leave well enough alone. Simple bolt-on cold air intake and cat back exhaust just won’t cut it. That means it is time to upgrade your cooling system components accordingly.
Some may argue that upgrading your radiator should be at the top of any Fox Body owner’s mod list. I would have to say that is a fair assessment. The puny factory radiator holds little fluid and is a cooling nightmare for heavily modded Foxbodies. If you still have the factory radiator it is well past its prime and should be replaced.
Why not upgrade when you replace? Some of our customer favorites are the Fluidyne and SVE Radiators. These Mustang radiator upgrades feature direct fit design, full aluminum construction and maximum cooling capacity. All of these features equal cooler operating temperatures. They are available for both manual and automatic transmissions. Shop our complete list of Fox Body Mustang Radiators below!
Ditching the factory engine driven fan and clutch assembly in exchange for an electric fan reduces drag on the engine. This can help you pick up a little extra horsepower and if done properly will help increase air flow and cooling capabilities of your radiator. When it comes to installing an electric fan on your Fox Body Mustang there are several different options. Some of the most discussed ways of doing this are going and finding a junkyard electric fan off of a Mark VIII.
If searching for used parts isn’t quite your thing and you want a complete kit, you need to check out our electric fan kits in the link below! One of the most popular kits we offer is the Flex-A-Lite kits for the 79-93 Fox Body Mustangs. The Flex-A-Lite Black Magic Xtreme Electric Fan Kit comes with all everything you need to install an electric fan into your Stang.
NOTE: It is highly recommend that you upgrade your alternator when installing an electric fan in your Fox Body Mustang. Check out our 130 Amp Alternator Install video for help with this installation!