185s have one of the most reliable fleets in the country, therefore i see that maintenance is easily adequate and is currently adequate despite the out of course events you refer to.
Look below the cab window of the 185, you'll see a golden spanner
Forgot maintenance may be an issue for 170s on the "Scunthorpe shuttle", could do with a daily swap (there are times in the system for the 5T90/5T99 service I mentioned above on Monday to Saturday) with 1 Class 170 being swapped daily, this could see the 170s only spending 1-2 nights at Cleethorpes
Thanks, Sam