Gear box

Hello Ladies and Gents,

While checking the levels the other week I noticed the cap on the filler tube had popped up on the gear box filler I duly push fully in and a wekk later while checking again the cap had been push out not fully but almost.
I assume some sort of pressure build up? I have not refilled it with any oil since it's last service, is there a breather tube anywhere that i can check?

The breather tube rises (flimsy black plastic tube with a u-bend on the top) into the engine bay. Note that there was a recall to get these re-routed on some early disco models... They're about a metre long, and should be near the top of the engine bay to allow the wading depth. Check there's no kinks or blockages which could cause pressure build-up...

That pipe with the u bend nearly got connected to the spare union on the no4 injector. I mistook it for the tank return (yes I know it comes from the pump but I am fairly new to oil burners)

Thankyou for that.... I shall be checking it out over the weekend...unfortunately I have a few tasks on the landy. The proverbial sunroof leak i'm trying to fit these chores around the Six Nations ......

Have you checked that the two tabs that hold it down are not broken?