03-04 S/C Cobra “Do it yourself” Engine Coolant Flush
I’m not a professional mechanic by no means, use these instructions for informational purposes only and feel free to post any corrections or additional information as needed. Remember to follow common sense and use all safety precautions when working on your vehicle. I’m not responsible for any damage and or injuries that may occur due to you following these procedures. You perform them at your own risk!
1) Drive the car up onto a ramp/lift or jack it up so that the front of the car is higher then the rear. Having the car lifted so that you have plenty of room to move around and work is a must.
2) Let the engine cool off completely.
3) Remove the de-gasser/coolant reservoir cap.
4) Remove the crossover pipe cap at the bung located near the S/C snout. You’ll need a 1/8” square socket adapter, this will fit in the square opening in the middle of the cap. Make sure you thoroughly clean the threads from the cap and bung without damaging the rubber o-ring gasket that is built into the cap.
5) Use a wide flat head screwdriver to open the radiator peacock. Smaller flat head screwdrivers might damage the soft plastic peacock. Make sure you have placed a drain pan under the peacock and let the radiator completely drain.
6) Once the radiator has drained, remove the hose that runs from the upper cross over pipe to the lower thermostat housing. Remove the clamp at the t-stat side only and pull the hose off the t-stat housing. Again, make sure you have a drain pan located under the hose until it drains completely.
7) Now remove the hose that runs from the lower radiator to the thermostat housing. Remove the clamp at the t-stat side only and pull the hose of the t-stat housing. Only a small amount of coolant will drain from this side because most of the coolant has already drained out of the radiator peacock and the hose from step #6. This may be a good time to change to a new or lower temp t-stat?
8) The S/C Cobra uses 6 gallons of coolant. Only half of this has been removed so far. The rest of it is located in the engine block and heater core. To get most of the old coolant out before the flush begins, you must locate and remove the engine block coolant plug located on the driver’s side. Please note that there are two engine block plugs but the one on the passenger side is hard to get to because of the position of the starter and passenger side engine mount. You’ll need a 17-mm socket and extension to reach the driver’s side plug. It’s best to look for it by crawling under the car behind the driver’s side front tire, look up at the side of the block in the direction of where the mid-pipe meets the exhaust manifold. You’ll see a brass fitting near some freeze plugs. Note that the brass plug is not flush to the block and a few threads and sealant are exposed. Once you remove this plug and drain this side of the block, make sure you thoroughly clean the threads and re-apply high temp sealant. Put the plug back in and tighten it up snuggly without over-tightening. Remember that the plug is brass and the block is iron, the last thing you want is that fitting to strip or crack and possibly leak.
9) Now that most of the coolant has drained (4 to 5 gallons), it’s time to flush the system. Make sure the radiator peacock has been closed and re-clamp the hose from step #6 to the thermostat housing. Keep the other hose from step # 7 off; this will allow water that is still in the system to cycle through the radiator and escape while the engine is being flushed.
10) Turn a water hose on a low pressure setting and start to fill the crossover pipe bung. Once it starts to over flow, start the car, turn on the heater full blast and monitor the water temperature and the color of the fluid that flows out of the lower radiator house. As long as you keep filling the system with water, the water temp should never get up to normal operating temperature. After about 10-15 minutes of flushing the system, catch and inspect the water that is escaping out of the lower radiator. If the water is clear, the system is thoroughly flushed, if it’s not clear and still has debris in it, continue the flushing procedure until the water is clear.
11) When the system is clear, open the peacock and remove the hose from step #6 again, all of the water from the front cooling system should now drain out. Any left over water (approx. 3 gallons) will be located in the engine block and heater core.
12) Close the peacock and re-clamp all the hoses that lead to the t-stat housing. The cooling system should now be all buttoned up with the exception of the de-gasser and crossover caps.
13) Fill the system with the appropriate amount of coolant and water. Personally, at this point I added 3 gallons of coolant for a 50/50 mix but this is personal preference and depends on your driving style and geographical location. First, fill up the de-gasser reservoir and the crossover bung until full, then start the car, turn on the heater full blast and bring the system up to normal operating temperature. While the car is running, the system will automatically burp out any air bubbles and may require additional coolant and water to be poured in. Once the system has leveled out and up to normal operating temperatures for about 10 minutes or so replace the de-gasser cap and replace the crossover cap. Do not over tighten the cap, if snugged up correctly, the built in o-ring on the cap does a great job of sealing the system.
14) Check for leaks and take the car for a nice 10-15 minute spin while monitoring the temperatures. Once you get back, check for leaks again and shut off the car. After it has cooled off again, re-check the fluid level in the de-gasser, chances are that you’ll need to add more coolant or water at this point.
15) Please note that the 03-04 Cobra cooling system holds a total of 6 gallons, approx. 3 gallons in the front radiator, hoses, housings, etc. and approx. 3 gallons in the block passages and heater core. Keep this in mind when trying to figure out the amount of water, coolant and additives you would like to run in your particular system. In addition, distilled water is better suited for your cooling system but the above procedures will utilize mostly tap water since approx. 3 gallons will stay in your system during the flush. In addition, I highly recommend additives like “40 Below” or “Water Wetter”. In order for these additives to work to their full potential, make sure you follow the directions of these additives in regards to your Water to Coolant mix. When it comes to choosing the proper type of coolant for your Cobra, go with your personal preference or follow Ford’s recommendations if you’re unsure!
Now go and enjoy your cool running Terminator!!!
Later…Dave(SCT2003)
I’m not a professional mechanic by no means, use these instructions for informational purposes only and feel free to post any corrections or additional information as needed. Remember to follow common sense and use all safety precautions when working on your vehicle. I’m not responsible for any damage and or injuries that may occur due to you following these procedures. You perform them at your own risk!
1) Drive the car up onto a ramp/lift or jack it up so that the front of the car is higher then the rear. Having the car lifted so that you have plenty of room to move around and work is a must.
2) Let the engine cool off completely.
3) Remove the de-gasser/coolant reservoir cap.
4) Remove the crossover pipe cap at the bung located near the S/C snout. You’ll need a 1/8” square socket adapter, this will fit in the square opening in the middle of the cap. Make sure you thoroughly clean the threads from the cap and bung without damaging the rubber o-ring gasket that is built into the cap.
5) Use a wide flat head screwdriver to open the radiator peacock. Smaller flat head screwdrivers might damage the soft plastic peacock. Make sure you have placed a drain pan under the peacock and let the radiator completely drain.
6) Once the radiator has drained, remove the hose that runs from the upper cross over pipe to the lower thermostat housing. Remove the clamp at the t-stat side only and pull the hose off the t-stat housing. Again, make sure you have a drain pan located under the hose until it drains completely.
7) Now remove the hose that runs from the lower radiator to the thermostat housing. Remove the clamp at the t-stat side only and pull the hose of the t-stat housing. Only a small amount of coolant will drain from this side because most of the coolant has already drained out of the radiator peacock and the hose from step #6. This may be a good time to change to a new or lower temp t-stat?
8) The S/C Cobra uses 6 gallons of coolant. Only half of this has been removed so far. The rest of it is located in the engine block and heater core. To get most of the old coolant out before the flush begins, you must locate and remove the engine block coolant plug located on the driver’s side. Please note that there are two engine block plugs but the one on the passenger side is hard to get to because of the position of the starter and passenger side engine mount. You’ll need a 17-mm socket and extension to reach the driver’s side plug. It’s best to look for it by crawling under the car behind the driver’s side front tire, look up at the side of the block in the direction of where the mid-pipe meets the exhaust manifold. You’ll see a brass fitting near some freeze plugs. Note that the brass plug is not flush to the block and a few threads and sealant are exposed. Once you remove this plug and drain this side of the block, make sure you thoroughly clean the threads and re-apply high temp sealant. Put the plug back in and tighten it up snuggly without over-tightening. Remember that the plug is brass and the block is iron, the last thing you want is that fitting to strip or crack and possibly leak.
9) Now that most of the coolant has drained (4 to 5 gallons), it’s time to flush the system. Make sure the radiator peacock has been closed and re-clamp the hose from step #6 to the thermostat housing. Keep the other hose from step # 7 off; this will allow water that is still in the system to cycle through the radiator and escape while the engine is being flushed.
10) Turn a water hose on a low pressure setting and start to fill the crossover pipe bung. Once it starts to over flow, start the car, turn on the heater full blast and monitor the water temperature and the color of the fluid that flows out of the lower radiator house. As long as you keep filling the system with water, the water temp should never get up to normal operating temperature. After about 10-15 minutes of flushing the system, catch and inspect the water that is escaping out of the lower radiator. If the water is clear, the system is thoroughly flushed, if it’s not clear and still has debris in it, continue the flushing procedure until the water is clear.
11) When the system is clear, open the peacock and remove the hose from step #6 again, all of the water from the front cooling system should now drain out. Any left over water (approx. 3 gallons) will be located in the engine block and heater core.
12) Close the peacock and re-clamp all the hoses that lead to the t-stat housing. The cooling system should now be all buttoned up with the exception of the de-gasser and crossover caps.
13) Fill the system with the appropriate amount of coolant and water. Personally, at this point I added 3 gallons of coolant for a 50/50 mix but this is personal preference and depends on your driving style and geographical location. First, fill up the de-gasser reservoir and the crossover bung until full, then start the car, turn on the heater full blast and bring the system up to normal operating temperature. While the car is running, the system will automatically burp out any air bubbles and may require additional coolant and water to be poured in. Once the system has leveled out and up to normal operating temperatures for about 10 minutes or so replace the de-gasser cap and replace the crossover cap. Do not over tighten the cap, if snugged up correctly, the built in o-ring on the cap does a great job of sealing the system.
14) Check for leaks and take the car for a nice 10-15 minute spin while monitoring the temperatures. Once you get back, check for leaks again and shut off the car. After it has cooled off again, re-check the fluid level in the de-gasser, chances are that you’ll need to add more coolant or water at this point.
15) Please note that the 03-04 Cobra cooling system holds a total of 6 gallons, approx. 3 gallons in the front radiator, hoses, housings, etc. and approx. 3 gallons in the block passages and heater core. Keep this in mind when trying to figure out the amount of water, coolant and additives you would like to run in your particular system. In addition, distilled water is better suited for your cooling system but the above procedures will utilize mostly tap water since approx. 3 gallons will stay in your system during the flush. In addition, I highly recommend additives like “40 Below” or “Water Wetter”. In order for these additives to work to their full potential, make sure you follow the directions of these additives in regards to your Water to Coolant mix. When it comes to choosing the proper type of coolant for your Cobra, go with your personal preference or follow Ford’s recommendations if you’re unsure!
Now go and enjoy your cool running Terminator!!!
Later…Dave(SCT2003)
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