can someone school me on the difference? i can't seem to figure it out. i went to the parts store today for a 16lb cap and there were two identical caps but one was marked "vented" and the other just said 16lb. i'm not talking about the ones with levers either. these caps appeared identical but upon closer inspection, i noticed that the bottom "plug" type piece would hang freely on one while the other was spring loaded up into the seal. it's my understanding that both types of radiator caps facilitate flow in both directions... perhaps one just does it with less vacuum?
for example, Stant part #'s
No. 11230: 16 lb. cap
No. 11231: 16 lb. cap-vented
from "rockauto"
STANT Part # 11230 {Standard Cap (Open or Closed System) - 16 psi (SAE Range 14-18 psi)
STANT Part # 11231 {Standard Vented Cap (Open or Closed System) - 16 psi (SAE Range 14-18 psi)
Thanks!
for example, Stant part #'s
No. 11230: 16 lb. cap
No. 11231: 16 lb. cap-vented
from "rockauto"
STANT Part # 11230 {Standard Cap (Open or Closed System) - 16 psi (SAE Range 14-18 psi)
STANT Part # 11231 {Standard Vented Cap (Open or Closed System) - 16 psi (SAE Range 14-18 psi)
Thanks!