Rusty swivels, MOT failure or not?

Are rusty swivels an MOT failure, or are they only a failure if they are rusty and actually leaking oil?

I intend to change the offending one but it would be nice to know in the meantime. Also, the Haynes manual talks about Land Rover now substituting oil with grease, is this any better, and due to viscosity is it likely to leak less?

Thanks!!

PS Just bought a cheap older Disco, you might see me in here a fair bit!

spray em with wd40 to get rid o the rust then fill em with grease to stop em leaking, mind you, thinking about it, if they are rusty they aint leakin

only if they are leaking is it a fail and even then only if the oil can get onto the brake discs or brake pads.

My disco manual says that a grease has been substituted instead of oil in the swivels and there are stickers under the bonnet saying its been done. This mod has been in operation since 1998