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How To Flush F-150 Lightning Cooling System (1993-1995)

Posted 10/24/2019 by Cristian Coronado

Learn how to flush your F-150 Lightning Cooling System (1993-1995) with our step-by-step article!

FOLLOW: ford lightning , 93 95 lightning , cooling system , how to

How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)

  1. Support the front of the truck with jack stands or the entire truck with a lift.


  2. Open the radiator cap to vent the system, then position the drain pan under the drain plug.

  3. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  4. Attach the appropriate size hose, open the drain plug and allow the coolant to begin draining.

  5. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  6. Locate the heater return hose, this will be the hose above the alternator. Squeeze the clamp and move the clamp. Then slide the hose off the tube to attach a piece of scrap hose.

  7. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  8. Use a 5/8 barbed fitting with a female connection, then attach the garden hose coming from the hose bin.

  9. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  10. Use the 5/8 barbed fitting with male garden hose thread and install it into the heater return hose. Then screw on a short garden hose to the fitting and ensure it’s tight (be sure to reinstall the radiator cap).

  11. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  12. Place the short garden hose into another bucket then turn the water on, but do not run it wide open. You will want to verify nothing in the cooling system is clogged or stopped up. (if there is not a blockage you can skip to step 11)

  13. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  14. A common issue with the lightnings is a stopped-up heater core. Remove the fitting while it is still connected to the short garden hose.

  15. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  16. Locate the heater supply hose and remove the hose (this will be the hose connected to the tube coming from the intake manifold).

  17. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  18. Use a second 5/8 scrap hose to connect to the tube, then insert the barbed fitting into the hose.

  19. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  20. With the water running and the drain plug open, start the truck and allow It to get up to operating temperature. Let the truck run until the water is clear(keep an eye on your temp gauge and be mindful of how full your buckets/drain pans are as well).

  21. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  22. Once the water is clear, turn the truck off followed by the water. Allow all the water in the radiator to drain out. Once it slows to a drip remove the hose and close the drain plug.

  23. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  24. Wipe up any mess and remove the water supply hose and the drain hose from the truck. Leave the heater core bypassed if it was stopped-up.

  25. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  26. Loop your scrap hose and connect the tubes together and reposition the clamps. If the heater core was not backed up, reconnect the heater hoses to the respective tubes.

  27. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  28. To flush the overflow tank, remove the overflow hose from the nipple on the radiator.

  29. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  30. Loosen and remove the retaining hardware from the overflow tank, then bring the tank up and remove the electrical connection for the windshield washer fluid, and remove the hose and cap the nipple.

  31. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  32. Thoroughly clean the coolant reservoir with an all-purpose cleaner degreaser and then rinse. You have to repeat this step a few times in order to break down any stuck-on gunk.

  33. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  34. Once clean reposition the overflow tank and connect all the hoses and electrical connections along with the retaining hardware.

  35. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


  36. Fill the overflow tank with fresh coolant to the indicated fill line, also top off the windshield washer reservoir. You can also go ahead and install a new radiator or fill the one that is in the truck with fresh coolant. If using concentrate always dilute with distilled water.

  37. How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)


    How To Flush F-150 Lightning Cooling System (1993-1995) - How To Flush F-150 Lightning Cooling System (1993-1995)




About the Video

How To Flush F-150 Lightning Cooling System (1993-1995)

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Transcript
What’s up everybody! Landan with lmr.com! In this video, I’ll be showing you the easy steps on how to perform a clean water flush to the cooling system on your first generation Ford Lightning.

A complete coolant flush is typically only needed after several thousand miles and is usually often forgot about because of the fact that you don’t have to religiously do it.

This process is very easy to do and only requires a few supplies to get the job done.

Those include, several buckets or drain pans, a source of free-flowing water, a long water hose for the supply of water, a short water hose to act as a drain, two scrap pieces of five-eighths heater hose that are approximately a foot long, a small hose to attach to the drain nipple on the radiator, a five-eighths barbed fitting to male garden hose adapter, several rags or towels, an assortment of hand tools and of course fresh coolant.

Full disclosure here guys! Be ready to wipe up some coolant! This process can and will be messy.

To begin, support the entire truck via a lift or just the front with jack stands.

Open the radiator cap to vent the system.

Position a drain pan underneath the drain plug.

Attach an appropriate size hose over the drain nipple.

Open the drain plug and allow the coolant to begin draining.

Leave this drain plug during the flushing process.

Locate the heater return hose… this is the hose above the alternator.

Squeeze the clamp it and move it.

Slide the hose off of the tube.

Take a piece of scrap hose and slide it over the tube.

Insert the five-eighths barbed fitting with female garden hose connection.

Connect the garden hose coming from the hose bib.

Take the five-eighths barbed fitting with mail garden hose thread and install it into the heater return hose.

Screw on a short garden hose to the fitting and ensure that it’s tight.

Reposition the clamp if you’d like… since the water won’t be wide open, the system won’t be under much pressure.

Place the short garden hose into another bucket.

Be sure to reinstall the radiator cap.

Turn the water on, but do not run it wide open.

You want to first verify that nothing in the cooling system is clogged or stopped up.

If you notice the inconsistence flow of water coming from our drain hose, there is an apparent blockage somewhere.

If this happens, turn off the water… if it doesn’t disregard the next few steps.

A common problem on these trucks is a stopped up heater core… so we’re going to bypass it.

Have some rags ready so you don’t get coolant all over the engine.

Move the hose clamp back on the heater return hose and then remove the fitting while it’s still connected to the short garden hose.

Locate the heater supply hose… this is the hose that is connected to the tube coming from the intake manifold.

Slide a piece of scrap five-eighths hose over the tube.

Insert the barbed fitting into the scrap hose.

The heater core is now bypassed and you can resume the full system flush.

Turn the water back on… remember, you don’t have to have the water full blast!

Checkout the consistent flow water?! Also notice how murky the water is.

With the water running, and the drain plug open, start the truck and allow it to get to operating temperature.

Let the truck run until the water is clear.

Of course, be mindful of how full your buckets or drain pans are getting and of course keep an eye on the temperature gauge just in case.

Once the water is clear, turn the water off.

Allow all of the water in the radiator to drain out.

Once it slows to a drip, remove the hose and close the drain plug.

Wipe up any mess.

Remove the water supply hose and drain hose from the truck.

Leave the heater core bypassed if yours was stopped up.

Loop your scrap hose and connect the tubes together.

Reconnect each heater hoses to the correct tubes if yours wasn’t backed up.

Now we’re going to flush the overflow tank.

Remove the overflow hose from the nipple on the radiator.

Loose and remove the retaining hardware.

Bring the tank up and then disconnect the electrical connection for the windshield washer fluid.

Remove the hose and cap the nipple… If a little windshield washer fluid runs out, it’s okay… it isn’t the end of the world.

Drain the fluids from the tank.

Thoroughly clean the coolant the reservoir with an all-purpose cleaner/degreaser and then rinse.

You may have to repeat this a few times in order to completely breakdown any stuck on gunk.

Once clean, reposition the overflow tank and reconnect all of the hoses and electrical connection.

Reinstall the retaining hardware.

Fill the overflow tank with fresh coolant to the indicated fill line.

Also, go ahead and top off the windshield washer reservoir.

At this time, you can install a new radiator or fill the one that’s in the truck with fresh coolant.

If you buy concentrate, always dilute with distilled water!

Clean up your mess and be sure to properly dispose of your coolant.

After that, you’re good to go!

If this is your first time to ever do something like this, allow yourself a few hours to get it done.

A clean water flush of the cooling system is good to do whenever your owner’s manual instructs you to do so.

It’s also very important that you do this BEFORE you replace or upgrade the radiator or heater core in your truck!

To see more how-to and review videos covering industry leading products, be sure and subscribe to our YouTube channel, like this video, and turn on notifications. While you’re at it, checkout our other videos and shop LMR.com for all things 1979 to present Mustang and SVT Lightning!