I service my mtb brakes at least once a year and completely change the mineral oil. Its usually dirty.

I’ve been running my shimano road hydraulic brakes now for around 2 years and never touched them, they are spot on.

Does the road brake mineral oil get dirty like a mtb brake? Is it worth doing?

Thanks

yes and mineral oil deteriorates so yes you should change the oil yearly

I have Shimano brakes that are 8 years old and never been “serviced”. There’s simply no need to change the mineral oil. The dark colour is picked up from the seals and is not a result of external contamination.

My last mtb brake levers died after they stopped returning which I thought was caused by dirt.

I’m not convinced the seals stop 100% dirt getting in.