If you have a 140 then they are not a bad job to do. If you have a 180 then the front of the van has to come off and make sure that they order the whole unit as they will never get the two parts to seperate. WIll take anywhere between 6 and 8 hours to replace on a 180.
I just don't understand why they didn't look at the lack of power fault first before carrying out the service? Including the test plan it is probably quicker to carry out that diagnosis first than doing the service.
cheers