If the grease has gotten too hot or been overfilled then it can liquify and leak.  Grease will always be thrown out and will look oily.

Thanks mate . Is it normal that there is oil leaking out of the split in the boot ? Or does does mean the cv joint is leaking also? 

Just the boot, and it's far easier to change by splitting the pot joint, taking the whole axle out and replacing the boot from the inboard end rather than knocking off the CV.

I'd recommend sticking to a paper element unless you have access to a rolling road and an experienced operator to retune the engine after fitting a K&N.

Hi Guys,

Just wondering if you could help me . I have just bought a 1977 leyland ,i have a split in the rubber boot would you guys just buy the boot or buy the joint aswel ? prity new to this stuff ! . 

Also i want to change my air filter , if i remove the original air filter and put lets say a K&N one on ,what do i do with the pipe that runs to the current air filter as the new ones done seem to have this ? 

Hope this isnt a stupid question haha