Don't wanna blow coolant system! 23 psi for Pressure Leak Test?

windnsalsawindnsalsa Member Posts: 3
edited March 29 in Nissan
I don't want to blow the coolant system! Is much higher 23 psi rating true? [1998 Nissan Quest or Mercury Villager]

Please help! My pressure leak testing is delayed only because I found differing PSI numbers for the radiator SYSTEM. I will be using the Powerbuilt tester loaned from Autozone. I found the following numbers from various sources below:

...Leakage Test Pressure 157 kPa (23 psi), Cap Relief Pressure 81-109 kPa (11.8-15.8 psi) from sources:
+Villager [Chilton online via public library]
+Quest: [Chilton online via public library: can't seem to find spec]
+Quest: [FSM [factory service manual]

...16 psi???
+Haynes book for Quest/Villager, which didn't see mention of 23 psi:
page/section 3-1 "radiator pressure CAP rating" = 11.8-15.8 psi
page/section 1-2 "radiator CAP pressure rating" = 16 psi

Printed psi on cap itself:
+current on van: no spec. I don't know if OEM or 3rd party
+Oreilly, Autozone: 13 psi
+dealer: cap no longer available and no spec


  • docjdocj Member Posts: 6
    Do not do 23 PSI...never seen one that high
    I would pressure it to 13 PSI- that should be sufficient to find any leak
    Most vehicles are in the 13-16 Psi Range
  • windnsalsawindnsalsa Member Posts: 3
    Hi, thanks for your feedback. I've no experience with coolant system leak test. 23 seems higher than many others. From various forums, people have mentioned various psi numbers.,,ignificant discrepancies among the various documentations including your feedback (13, 16, 18, 23). I don't know what to do. I guess i'll try 13 initially, then 16. If leak, then that's solved; if none, then I wouldn't know if I should go further.
  • docjdocj Member Posts: 6
    Do not go any higher. system pressure is 13Psi .I wouldnt go higher than 15. Don't be surprised if you dont find a leak. some leaks can be difficult to find, even under system pressure. We sometimes have to add a leak dye to the system and then use special glasses to spot the dye . Dye and glasses can be bought at Autozone.
    Some leaks can be internal and slow. We sometimes have to leave the tester on over night and then look into the cylinders for coolant in the morning. Remember , as an engine heats up, things expand and leaks can seal up. small leaks can all dry up and evaporate with engine heat and wont be spotted.
    Also dont forget to pressure test the cap, Some caps can not hold system pressure and fail a pressure test.

    Fyi been at this game since the 60's
  • windnsalsawindnsalsa Member Posts: 3
    Did you come with the numbers 13-15 psi specifically for Mercury Villager / Nissan Quest or for across all makes/models? Any thought for the reason the 23 psi is stated in the factory service manual and in the online Chilton website?
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