T25 Thermostat “Which way up”?

[Xenolith05]

Hi all,
I have a 1985 2.1DJ WBX. The thermostat housing is the type shown here in this Thermostat Bundle
I took the old thermostat out a while ago while doing other maintenance, and now being an idiot, I can’t remember which way it goes in with the O ring!
So I looked in the Haynes manual, the VW workshop manual (pdf online), and Heritage Car Parts, but Heritage have it the reverse way round:

Heritage (scroll down) - Heritage Top Cover
Workshop PDF / Haynes - Workshop page 19-9 (same as Haynes)

Can anyone tell me 100% which way it should be / a picture would be great if you have one!

Thanks

[silverbullet]

Stat first, O ring on top as ut seals the cover bonnet.

[Xenolith05]

Thanks ‘Silver Bullet’ As per Haynes and the VW workshop manual then.

[maxstu]

I wonder how many owners' will lift their thermostat cap to check? And does it matter? I will check soon.
I can't recall which way round l fitted my recent seal and thermostat. Not leaking though.

[silverbullet]

Its intuitive if you are an engineer. The stat doesn't need sealing as it has a bleed hole and is a bypass device so is wet both sides.
The bonnet has a taper spigot which compresses the O-ring down onto the stat flange and out into the housing counterbore to seal.
Get it wrong and it will leak instantly.

PS the VW manual will always be correct and Haynes lifted their diagrams from the works manuals.
Heritage...maybe not so much.