BlueOvalTech Logo

How-To: Change your coolant

This tech article was originally posted at It is primarily intended for Ford trucks but most likely also applies to other Ford models.

NOTE: Follow these instructions at your own risk.

Tools needed for the job:

Parts needed:

Time required to complete:

Note: wear safety glasses while under the vehicle for eye protection as there's lots of dirt and grime under there just waiting to drop into your eyes.


  1. Wait until the vehicle has cooled off for at least 1/2hr if you've just driven it to avoid getting a "hot coolant treatment"... burns hurt!
  2. Place your drain pan under the passenger side front wheel well.
  3. Open the coolant expansion tank to allow air in to help drain the system.

Remove the coolant cap

  1. Locate the drain spigot, bottom of radiator, inside engine compartment, passenger side.
  2. Fasten your 1/2inch hose (about 6-12 inches long) on the spigot's spout which points to the passenger side. Use the 19mm open wrench to loosen the white drain bolt. Make sure your drain container catches the coolant as some will leak from the spigot drain bolt as well. Left arrow shows hose on spigot, right arrow shows spigot drain bolt. Bottom picture shows 19mm wrench loosening the spigot bolt.

Photo of spigot and drain bolt


Drain hose connected

Let it drain.

Coolant draining

Coolant draining

Coolant draining

  1. Take your garden hose and flush out the expansion tank, then let that drain also.
  2. When it's finished draining, pull the hose off the spigot and tighten the bolt. Don't over tighten it... it's plastic so 1/16 of a turn max.
  3. Locate the drain plug on the block. On my 98' 4x4 I found the plug just below the rear-most frost plug in the block on the driver's side accessible. Use a 17mm socket & wrench. They use loctite so you'll have to reef on there like a #%[email protected]&!!#@ so watch your knuckles. Wear leather gloves for safety. My engine block heater is also in that frost plug so it's a tight socket fit.

Coolant drain plug

The arrow shows the plug, pic taken from front of truck underneath looking up and rear-ward on driver's side of the motor. Closeup shown:

Close-up of coolant drain plug

  1. Make sure you have your drain pan underneath the motor before fully removing the plug in the block. Haynes manual shows a different picture, they say drain plugs are 1 inch above oil pan. Sort of accurate but their picture isn't accurate. There are too many brackets and the starter, etc in the way on the passenger side. If you have all day you might want to attempt it, I didn't.
  2. Let it drain. Now put some loctite on the drain plug threads after cleaning them off/drying them. Make sure the drain hole in the block is dry with paper towel. Then re-insert the plug. Put it in good and tight.

Be sure to apply Loctite

  1. Start filling in the coolant using your funnel. First the two jugs of antifreeze, then follow until full with distilled water. Let the engine come up to temperature and then check it again.

Photo of coolant and distilled water

  1. If the engine doesn't heat up fast enough you can always do a drive around the block or to the corner store. Then check the level again. Be very careful with opening the expansion chamber coolant cap while the engine is at operating temperature. This is very dangerous. If you have to then use a couple of rags to cover the cap, and open it slowly just a notch to let the pressure escape. If coolant comes rushing out close it immediately. Otherwise you can open it once the pressure is released.



This article has been generously donated by Peter Ferlow from