Under the bonnet of a V70 5d

[Maurice Mynah]

I hope by now most of you have recognised me as a complete imbecile on mechanics. but I am trying to improve.
Under the bonnet of my car (details on signature) just to the left of the power steering fluid reservoir, there is a cap on the top of a tube. It is just under an inch in diameter, and has on it a warning saying something like "Max 8 N.m"
on my car it is neither undone nor done up, I would guess it to be half way between.
Can anyone tell me what it is, and whether it should be done up or left loose. All I've managed to work out for myself is that if it should be done up, it shouldn't be done very tightly.
please advise :-)

[Stu B]

Without going outside to look under the bonnet of mine, if I remember correctly that’ll be the pipe where the AC gas is refilled. The cap will just be a dust cap as it’ll cover a valve so doesn’t need to be tight hence the low torque rating shown.

I’ll pop and look at mine tomorrow to confirm if no one else seconds that

[Tatsfield]

I'm sure that is the AC regassing port but surely the limit given on it is the maximum gas pressure to be applied to the system not the torque on the dust cap!

[Maurice Mynah]

Thank you both. Given that information I undid the cap and looked inside. It is indeed covering a valve, and looks to be something I need not touch.
This car is so complicated I am terrified to touch anything I can't identify.
Haynes is only of use if you know what it is you want to do, much the same as the on-line handbook.

[XC70Virgin]

It's the high pressure a/c connection point. The torque figure is the max for the connector being used. The lid is just a glorified dust cap.

[V70greg]

Originally Posted by Tatsfield

I'm sure that is the AC regassing port but surely the limit given on it is the maximum gas pressure to be applied to the system not the torque on the dust cap!

AC works on very high pressure, even the low pressure can be relatively high (30-40 psi as a rough guess, could be wrong though) compared to atmospheric pressures.

8 N/m is a measurement of force not pressure so I would guess it is the tightening force of the dust cap which would match the units and the energy referred to.

Maurice Mynah from memory that is the dust cap for the A/C just make sure it is not loose or falls off, over tightening with break the plastic. So long as it is there you are good.

[Maurice Mynah]

Thanks Greg, I tighten it to 'finger tight'