Black-Tooth
Tony Natoli
What I thought I knew and what I learned...
I am still having some cooling issues with my Vette when I thought they were all fixed. One area I hadn't been able to prove or disprove was my cap... because my Chinese Pressure Tester from HF could test every system known to man, but none of the traditional caps.
I now see that the Stant Testers on EBAY can be had for 30 to 80 bucks and they may not be able to test every system in the world, but they do not have a "gender-bender" adapter to test my cap.
A friend loaned me his and I got started testing my NEW 16 pound cap and found it would not hold but 13 pounds and still slowly dropped. I looked for leaks and submerged the entire thing in a sink under water and still no leaks!
I then took out my Chinese tester and used the Stant adapter with it and WHAA-LA... the exact same readings! I tested my OLD 16 pound cap and it was identical to the NEW one! I took the 13 pound cap off the FIAT and it was rock solid at 12 pounds and holding using BOTH testers...
My trip to Pep Boys resulted in the same findings. I was able to test several NEW caps still on their "hang-cards" with their "bottoms" exposed... and got the exact same readings! I purchased an 18 pound cap for the Vette and I'll see how that works as it indicates it will hold 16 pounds.
BTW...The 18 and 20 pound caps are $2 dollars LESS than the 13 and 16 pound caps... Supply and Demand at its finest!
Sooooo... I found the higher pressure caps were all 2 - 3 pounds LESS than their stated ratings... and their 13 pound cap just 1 pound less, which I've never had a problem with on the Fiat.
('74 X1/9s had about 7 pound caps and I3 pound caps work well on the others...)
I now wonder about what OEM caps actually worked at or work at... regardless of what was/is stamped on their covers. Do they too actually release pressure at 2 or 3 pounds LESS than what they are rated at?
I no longer have any OEM caps that I can test... Does anyone happen to know???
I am still having some cooling issues with my Vette when I thought they were all fixed. One area I hadn't been able to prove or disprove was my cap... because my Chinese Pressure Tester from HF could test every system known to man, but none of the traditional caps.
I now see that the Stant Testers on EBAY can be had for 30 to 80 bucks and they may not be able to test every system in the world, but they do not have a "gender-bender" adapter to test my cap.
A friend loaned me his and I got started testing my NEW 16 pound cap and found it would not hold but 13 pounds and still slowly dropped. I looked for leaks and submerged the entire thing in a sink under water and still no leaks!
I then took out my Chinese tester and used the Stant adapter with it and WHAA-LA... the exact same readings! I tested my OLD 16 pound cap and it was identical to the NEW one! I took the 13 pound cap off the FIAT and it was rock solid at 12 pounds and holding using BOTH testers...
My trip to Pep Boys resulted in the same findings. I was able to test several NEW caps still on their "hang-cards" with their "bottoms" exposed... and got the exact same readings! I purchased an 18 pound cap for the Vette and I'll see how that works as it indicates it will hold 16 pounds.
BTW...The 18 and 20 pound caps are $2 dollars LESS than the 13 and 16 pound caps... Supply and Demand at its finest!
Sooooo... I found the higher pressure caps were all 2 - 3 pounds LESS than their stated ratings... and their 13 pound cap just 1 pound less, which I've never had a problem with on the Fiat.
('74 X1/9s had about 7 pound caps and I3 pound caps work well on the others...)
I now wonder about what OEM caps actually worked at or work at... regardless of what was/is stamped on their covers. Do they too actually release pressure at 2 or 3 pounds LESS than what they are rated at?
I no longer have any OEM caps that I can test... Does anyone happen to know???