Esoteric question of the evening.

[Napes]

What is the O.D. of the the inlet and outlet pipes on an OEM radiator? I want to get some plumbers rubber caps to seal the radiator so I can imersion-test it for a probable leak. TIA

Bob Napier

[Mike Self]

you go down to a hardware or plumbing supply shop and buy a couple of properly sized plumbers internal expanding plugs. They're black rubber disks with a bolt and wingnut thru the center. Tighten the wingnut and it expands the plug. They're used to cap a waste line if you have to remove a pluming fixture like a kitchen sink or toilet--keeps sewer gas from leaking into the house (ugh!)

That's actually what radiator shops use...

cheers

mike

[Pinepig]

Take 2 condoms and place them over the inlet and outlet of the radiator.

Put your pressure relief radiator cap on and lift the relief handle, inflate the condoms a bit by blowing some air in the relief hole with a compressor or a tube and you mouth. Spray with soapy water or dip in a tank of water.

[ingraham]

If you test just below that, the normal radiator cap should not release. For a better test, use a plug (as Mike described) instead of the cap, and run the pressure up to 1.2 atm or so.

I doubt condoms will hold at 1 atm. Maybe Pinepig knows of a special variety?

[Pinepig]

If you test just below that, the normal radiator cap should not release. For a better test, use a plug (as Mike described) instead of the cap, and run the pressure up to 1.2 atm or so.

I doubt condoms will hold at 1 atm. Maybe Pinepig knows of a special variety?

That's how you test homebuilt aircraft fuel tanks. I wouldn't think if you have a leak it would take much pressure at all for it to blow air.