valve cap seal

[1131dolphins]

my valve cap had a circle imprint in it maybe i put it on too tight
i ordered a new one it will be here in a few days
any tips

[tbirdtbird]

Those plastic caps are the final seal, of course not the schrader underneath. There should be a rubber gasket deep inside the cap. I would not be surprised if there were a bit of an indentation on the rubber. They need to be snug but not so tight as to crack the plastic

[JohnHere]

Is the refrigerant leaking out, is that why you tightened the cap excessively?

[1131dolphins]

I just did a evac and charge with a 30lb drum
the first charge was with cans 2 which is 24oz not the 27oz required plus disnt purge the lines
this charge is better now
it cools better and the vent temps are consistant now
i put the caps tight because i worried it will leak out but obvious put it too tight

[JohnHere]

Incidentally, what vehicle and year are we discussing here?

[1131dolphins]

its a 08 mercury grand marquis
i just got the motorcraft caps in the mail
i installed them as snug as possible not as tight as possible
i took the old caps ring out and it had a new inpression than the first time
it was deffinitly too tight the impression was almost through the ring

[1131dolphins]

i guess i could put the leak detector on the caps to see if there snug enough
when i removed the low side no pressure under the cap
the high side cap had a little pressure in the cap

[JohnHere]

I just did a evac and charge with a 30lb drum
the first charge was with cans 2 which is 24oz not the 27oz required plus disnt purge the lines
this charge is better now
it cools better and the vent temps are consistant now

Did you weigh-in the charge of 27 ounces or guesstimate it?

What are the center-vent temperatures, HS and LS pressures at 1,800 RPM engine speed, and the ambient temperature when you recorded those readings?

With the caps on securely, you should detect no leakage.

[1131dolphins]

i used a scale and weighed in the freon
the vent temp gets close to the 40 degree mark and stays pretty close to that while driving around
the pressure is about 50 and 150 i didnt really pay attention too much to that

[JohnHere]

i used a scale and weighed in the freon

Excellent.

the vent temp gets close to the 40 degree mark and stays pretty close to that while driving around
the pressure is about 50 and 150 i didnt really pay attention too much to that

The vent temps are very good, but I can't reconcile them with the pressures you posted. However, if you're satisfied that it's cooling well and the new caps aren't leaking, I would leave it alone.