The 180s weren't running a full schedule the week just past. I usually catch them both ways to work in Manchester and only one of the services Tue-Fri was operated by a 180. They were replaced by either a single 156 (mornings) and a single 142 on Friday evening.
The 156 was standing room only by Adlington on the way in to Manchester and was not able to pick up a lot of passengers from Blackrod onwards. The evening trains back (19:28 ex Man Vic) can cope with a single 156, but was pretty busy. The 142 was standing room only until Bolton though.
Not sure what the problem was last week and whether it will drag on to this week as well, but if you are looking out for them this week, they may not be on full schedule again, although as a passenger I hope they are.