The one went out in my car and I installed a Spectra Premium from CarId that leaked all over my floor. The limited lifetime warranty advertised did not apply to the item advertised, so I ordered the same one from AutoZone, which just says "Limited lifetime," without three paragraphs that end with "Spectra Premium Radiators, Condensers, Heater Cores and Ignition Distributors have no warranty."
I just want to make sure that it is good before I install it, I don't want to be doing this a third time [and potentially fourth and fifth]!
I trimmed down a Schrader valve to fit in one hole, clamped it in-place, inserted a rubber plug into the other hole, and used a bike pump to pressurize the heater core to 16 PSI, which is the cooling system's rating. The air leaked out within a few minutes, although I never heard any hissing.
Is the problem with the heater core or my rig?
Oh! How do I remove a rubber stopper from a hole?! My rig pushed it almost all of the way in! I don't want to put a hole in it!

  • Welcome to Motor Vehicle Maintenance & Repair! Jul 9, 2020 at 11:11

1 Answer 1


Once you have pressurized it, immerse it in the bath to see where any leaks are, just like doing a bicycle inner tube repair.

I would also keep the air supply connected so you get a constant stream of bubbles if there is a leak.

Make a handle for the stopper before you get it stuck, now you need to drill a hole deep enough to put as screw in it, without going all the way through.

  • The heater core fins trap a great deal of air and I would be unable to distinguish leaking air from bubbles just trapped by the fins.
    – Menlo Part
    Jul 9, 2020 at 16:27
  • @MenloPart just too challenging sometimes.
    – Solar Mike
    Jul 9, 2020 at 16:39

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