Hello all. This probably is a stupid question. Is there a secret trick to replacing the coolant temp sensor on my 2002 escape 3liter? Mine is leaking and pull the clip and easy to remove. However unable to push the new one in. Unfortunately not threaded and unable to push new one in and replace clip. Have struggled and struggled. Just a weakling??

 

If you have not slathered the O-ring with some lubricant, it will be difficult to get it to smush into the hole. You can use something as simple as Vaseline, or go to silicone grease, or even a thin coating of motor oil. Just enough lube to get the O-ring to squeeze and compress into the bore. Dry, it will hang, and attempt to cut the O-ring rather than slide and compress. I base this on the images from oogle showing a built-in O-ring on the sender.
tom

 

Have tried that, just cannot push it in. I figured there was some seceret trick.

 

Go the expense and get the proper lube when it comes to o-rings, especially around oil or any real form of pressure.

Being in the coolant system, you should be able to get away with just a small touch of dishwashing soap. Just enough to make it slippery. Never use soap around oil.

O-rings can degrade with the wrong lubricant and you'll likely end up doing it again sooner than you wanted to if the wrong lube is used. Also, remove and inspect the current o-ring for damage from pinching.

 

Your not supposed to use silicone grease on silicone "O" rings but you can if they are made of nitrile rubber sometimes called buna-n. Trying to find out what they are made of is probably a lost cause!

I use Dow Corning 55 Molykote Medium O-Ring Grease but it claims to cause a tiny bit of swelling but I've never seen that yet on anything I used it on. It's used in pneumatic systems in aircraft, automotive and general industrial applications.