Refrigerant Type: R-134A
Country of Origin: United States
Can anyone point me to a good source of R-134A service valve caps? A metal cap with an o-ring would be ideal. Any recommendations appreciated. I don't need a large quantity of these, just want to replace my own.
I've never seen a metal 134a cap-- they don''t exist, as far as I know. Plastic works fine as long as trhe rubber seal is present-- besides you wouldn't want that galvanic corrosion between two metals (aluminum and whatever you choose) to build up in the cap area and then you would not be able to remove the cap without pulling off the threads..
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......
Thanks. I will take a look at some local stores then.
Go to about any car dealer's parts counter. Any that they have will probably be better than what you find on the aftermarket.
I kept breaking my service valve caps while off working around them with tools. Many places only sell the caps along with the conversion adapters...too expensive, and not necessarily any better quality.
I found a relatively cheap source at a large NAPA store (the central depot for my area) for $1.89 a pair. So far, I haven't broken them off, but then I've learned to be careful around them. Still, at that price I bought a spare pair.
Those NAPA service caps will be fine if they are like the ones I get at my local NAPA store. They are very close to the OEM caps. The plastic is a bit flexible and will take a bump or slight overtightening.
The caps available at the "chain" parts stores are brittle and break with a good hard stare.
I looked at the low side cap on my '01 Grand Marquis recently. No o-ring at all, but it seems to seal. I got the car when it was 2 years old, so I think I am the only one who has ever removed the cap.
There looks to be a small leak inside the schrader valve, I first noticed this after I topped it off. It was bone dry before. I guess you all have now guessed why I want the best sealing caps.
Edited: Mon August 25, 2008 at 10:27 PM by Mattb
On a another note, as far as getting nice replacements, it looks like '01 Ford caps have a much longer thread than the standard caps. I've found some nice replacements with o-rings, but the threads are just too short.
Maybe I will just drop a correct size o-ring in the OEM caps and leave it at that.
Edited: Sat August 30, 2008 at 8:29 PM by Mattb
Whats up with the useless and flimbsy aftermarket caps? You cant tighten them down w/o them pulling the plastic threads out of the cap and others will depress the schrader when tightened.
I just got my money back yesterday ($3.99) for a set of "Qwest" caps from AutoZone, both were broken within two months (broke on the vehicle while running, threaded part broke off), and I did NOT overtighten them, just lightly hand tightened them. I bought replacements from CarQuest total $1.92 yesterday as well; those new ones were also color-coded blue and red plastic, Qwest's were black.
The CoolPro caps I got were very nice, here is a link:
Thick plastic and beefy o-rings. They probably fit everything else besides my Ford.
Edited: Sun August 31, 2008 at 11:48 AM by Mattb
We use and sell the Coolpro caps. No issues with breakage in our shop or complaints from customers.
TRB and others: I was under the impression that the Schraeder and other types of AC valves typically leak, and that a good quality cap has a major function to help hold in refrigerant: is that correct? My local mechanic told me otherwise, and he's pretty good at AC, and I didn't want to contradict him. Please reply.
You most likely have some seepage through the valve core, but it's still the primary seal. The cap and o-ring are the secondary seal and is why it is suggested to have a good cap/o-ring.
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