So my dads 6.0 randomly blew coolant out of the cap even though I replaced the cap again with a oem cap a few months ago. So I bought a $100 coolant cap tester kit with various cap styles, go figure it didn't come with one for a ford cap. For the life of me I cannot find a fitting for the ford 6.0 cap?? Anybody have a part number or link to one? I would prefer a test cap with a quick release fitting. I want to make sure it's the coolant cap going bad and not headgaskets. Thank you.

 

Put a pressure gauge on one of the small hoses that tie into the degas bottle. That is easily done and will tell you what you want to know - as it ALSO will show you the performance with the the cap that you have installed. Without it, you will always be guessing, at least a little.

Like all pressure relief devices, once you have a few "over-pressure" events with hot coolant going through the cap, it will tend to relieve at lower pressures going forward; but the first release events were almost always driven by a true force and not a weak cap from what I have seen anyway. I have had a lot of caps and have never had one OEM cap relieve early (during testing).

EDIT:
Just fabricate a small "add-on" hose piece with a tee. The new section from the tee can have a schrader valve installed so that you can add regulated air from a compressor, and then VERIFY the pressure with a tire gauge......VERY easy and cheap. It is easy enough to verify a tire gauge (stick) to be accurate, so once you get one that is accurate to within a psi or two, then you will be all set. I have never found this hard to do (but I do check every one that I have bought and only a couple have been bad). Pressure up the system with the shop air to 15 psi (or whatever) and see if it hold. We depend on these stick gauges for our tires, so it is more than adequate for this task, and it is easy.

 

I had not found the right adapter either. Therefore, I had made my own.


I recently had a truck here where the seat for the cap on the degas bottle was the problem.

 

A couple of years ago O’Rileys had a coolant pressure test kit. $160 plus $40 for two adapters in smaller, separate box. One of those extra ones fit my 2006 degas bottle. Wish I had noted the p/n but I didn’t. If you don’t want to keep it they return for 100% refund.

This is a picture of the one I rented, below is a pic of the one on the website. The one that fits our degas battle is in the adapter set.

 

https://www.ebay.com/itm/16567645719...3ABFBMlvKbgaFh

 

AutoZone also has the correct adaptor kit.
I don’t recall the number. But it was fairly
easy for them to find it.

 

Here is the one you are looking for.




Here is the part numbers.

 

I went to orielys and did a pressure check using their kit. So since I needed a new cap I did pressure check on 2-3 new caps before I found one that held pressure. Only cost was for new cap.

 

What brand were they?

 

Did a short video today. Only Motorcraft cap worked!

 

The kit I showed is one of the "Free" use ones.

 

totally agree!

 

Nice visual test.

On my 05 6.0PSD with 180k miles and 7 years it still had the original cap and my '12 6.7PSD with 250k miles still has the original cap.