New head gaskets won't seal

[89Ru]

1 hour ago, GeneralDisorder said:

...pressure test rig might have experienced pressure drop simply from the compressed air falling in temperature (and therefore pressure). GD

Good thought.  That's engineering talk.  If I ever do this again I'll try to remember that.  PV = nRT and all that.  

I used to use only Subaru rad hoses.  I've gone cheaper, these are probably Gates.  They don't fit quite right and the old style OEM wire-bolt clamps don't work as nicely anymore.  Those new compression band clamps seem to have too small ID.  Wonder if they fit better with Subaru hoses.  Thinner wall and therefore reduced outer diameter?  

[GeneralDisorder]

Correct the wire clamps only fit the OEM hoses due to their reduced wall thickness. Personally I like the OEM wire clamps. They have very even clamping force. We use the embossed worm clamps with rolled edges and a thinner band if the wire clamps are not reusable. We use exclusively OEM hoses or silicone hoses (bulk or fitted) for performance applications. For anything around 1.25" and smaller we use exclusively tongue and groove Oetiker clamps. 

GD