I’m no expert, but assume it happens when a big split occurs.
I like to give mine a bit of right foot on a regular basis to blow out any cobwebs. I have a theory that getting revs above 4000 is beneficial for the motor.
Another benefit is when a very small split occurs it shows up early. I gave mine a bit if right foot when the engine warning light came on. Fortunately with some more sedate driving I was able to get home and temporarily tape up the affected area.
Then I got some great silicone hoses from Roverlord Offroad Spares. Thanks Mario. [emoji106]

