well I went out today and Stant caps are rare here. I got 2 from Oreilly's and asked to use a pressure checker. I was told I needed the truck to make it work, anyhow the store I was at did not have one. Went to another about 2 miles away with the 2 caps. The girl there said the same as the 1st guy, but she did have the checker AND the screw on adaptors. Well got the thing all put together, 1st held the 16psi, the 2d did not. She had a cap and it was worse than the one I was having problems with. She told me to go to another store who had 4 caps and the tester and the adaptors. Stopped by Pep Boys, they carry stant, tried to find the 10238 cap, they didnt have any, but another store had the 11238 (the new number). Got one but they didn't have a tester and the guy was like the 1st 2 said he didnt think you could check just caps! Finally went to the 3d Oreilly's got the same runa round about the testers but they had 1. It didn't work, got another, then told them I needed the adaptors (no pictures on the tool mat so they were lost) told them it was in a plastic boax about so big, guy found it. Hooked it up and went through 2 more caps and they also did not hold the 16psi.

So will take back 1 tomorrow (BTW same cap for an F150 5.4, sons truck). Bottom line is test your caps before leaving the store. 5 caps checked 1 held pressure in my case. BTW I have the original cap on mine so I know its probably one of the suspect ones in the video, but I have no leaks from it, but whats $5 for a potential problem solver?

The murray caps from Oreilly are made in Israel, the guys told me most of the others come from china, stant says USA?

 

Stant is USA, Assembled in Mexico

 

OK there is a problem with the caps! We are agreed on that; RIGHT?

The clerks in the parts stores are just that, Clerks. They are not Mechanics.
The parts stores around me ( Advance, O'Reillys' and the Zone) all have cooling system pressure testing sets for loan.
The problems Hank had testing caps may have been as simple as the test set was malfunctioning.

I agree that a test of a new cap should be done to ensure that it functions correctly.
When you get a new cap GO TO A REAL MECHANIC AND HAVE IT CHECKED.
If you have any doubt go to a radiator shop.
THEY WILL KNOW HOW AND CAN CHECK THE CAP.

I do not have a test set but my best friend does.
In fact he and I are changing the front calipers on my van at 9am today.

I will be checking out three of my old caps and some new caps then.
The only reason I'm not checking the cap on my F-150 is that it is at my FIL house and not here with me.
I will have a good new cap for the next time I do get that truck here however.

I'm not making any assessment of anyone's skill level that is posting here.
I have made a living as a mechanic and do the work on my own vehicles.
I also maintain the F-650 (Cummins engine) and F-450 (7.3L) tow trucks that I drive.

When in doubt seek professional help.

As to the knowledge of the video mechanic I could care less.
The theory that has been put forth rings true to me and that is enough for me to investigate it.

 

What I got out of the video was to inspect my cap. It made me look and see if there is a chance of an issue. I never really looked before. It did have an issue, so from there I can say that the guy did give us a heads up on a potential threat to our engines. All I can say is faulty pressure on the rad cap is a problem especially here in Texas where it heats up trememndouly. The physics actually tells the story by itself. Less pressure, lower boiling point.... If the cap is bad, replace it, we used to do it on older vehicles, why would now be any different?

 

It seems to me that it would be relatively easy to install a pressure gauge off the degas bottle, that way you can monitor it all the time.....

 

don't get wrapped around axle over this. It if does not leak, leave it alone.

 

Personally I think the caps are probably made from the same manufacturer. The old design was found to be weak and was changed or decided to make a new design for newer 2009 and up. I bet they still use the old caps for other vehicles from ford.

I think ford as usual kept hush on this to save their A** or techs did not know these caps were failing and diagnosed as something else when the motor blew.

 

FWIW, the cap on my Feb '09 build has a fairly large diameter spring, 3/4" at least and the cap is marked "Made in India" so I don't think the caps are all from the same manufacturer. I didn't see any evidence of leaks, but I haven't been able to pressure test yet.

 

i picked up one yesterday...however the nearest part store was a AutoZone and they did not carry Stant they had CST(Cooling System Technologies) part #7038....hoping this is just as good.

on another note AutoZone sucks they dont carry any Motorcraft parts at all

 

I will cos mine is not leaking!

 

This is still great information, I'm going to go to Napa and Autozone and see what I can find.

 

I wonder if this degas cap issue could have any relation to the F-450s/550s having the cavitation issues eating through the front of the engine. Boiled coolant (steam) being pumped through the engine can't be good.

I guess I don't run mine hard enough, it always runs below 206DF, too cool to boil.

Having the cap checked as a preventative measure.

Tim

 

Cavitation of the front cover on those trucks has a better chance of being the fact that this cooling system is designed to FLOW a serious amount of coolant. That coupled with the rpm's the 4 and 550s turn are your problem with from cover issues.

 

I agree, the water pump is designed to flow a huge amount of COOLANT, not necessarily steam bubbles in boiling coolant. Was just a thought, I'm not a flow engineer or anything. Tim

 

Replaced the cap on the '08 F350. It had a residue on the underside of the cap and on the bottle, which seems to indicate condensation of lost steam. Also, the coolant was about a quart low. Truck has about 22k miles on it.

Same cap on my '07 Mustang GT. No residue. No coolant loss. This car has 23k miles.