Mercedes Actros

Whilst we’re on the subject of Mercs, we had 3 turn up last June, 3 days apart. All have similar mileage (95-110k) and pull similar weight over days/nights. Couple of weeks back, I pulled out the yard, bit more gutless than normal, struggled to make ground on M4 e/b from j11 up the hill, got to 1st depot (I do 2 on a Tuesday…get me on the multidrop eh!!) and weren’t much better for the rest of the night. Following morning, text comes in, day driver broke down in yard… Exhaust brake stuck on, temp fix carried out by dealer, went in last week for repair. FF to y’day, the 2nd one that arrived broke down in the yard, same problem. Dealer has already been booked to be in the yard for 4:30am in a fortnight to fix the other! Any others had this problem with a brand new Actros? Incidentally, this is the exact same fault my old 52plate 2553 suffered from, which is what made it cut out if the revs dropped below 900-1100rpm and the retarder was in use along with the brakes