The following information is from the Railcar Association website:
The first four sets were delivered in April (2) and May 57 (2) to Longsight, the first of two batches of 3-car sets for the LMR. They entered service on the Buxton line on the 17th June 1957. The second batch of 52 sets were also delivered in 1957.
An early sighting was 50420/4 & 59132, with B1 on the route indicator, working from Longsight on the 20th April '57.
Noted at Longsight on the 19th May '57 were 50421/59133/50425 & 50423/59135/50427.
Noted working the Manchester - Buxton - Crewe services on the 17th June '57 were 50423/59135/50427, 50428/59136/50480, 50430/59138/50482 and 50431/59139/50483.
On Monday 16th September 1957 sets were introduced on an improved service between Crewe and Derby via Stoke. There were some half dozen more trains in each direction on weekdays, and three more on Sundays. Timings were based on an even-timed hourly service on weekdays and two-hourly on Sundays, with timings cut by some 27 mins compared with previous steam schedules. The 51 miles, stopping at all 23 stations between Crewe and Derby was covered in 87 mins.
Noted in use in the first days were 50435/59143/50487 and 50428/59136/50480. The only criticism they got was the noisy vibration of the luggage racks when in low gear.
At the same time a new fast diesel service was introduced to Llandudno Jct. The journey from Chester took one hour, and was advertised as being the fastest timing ever to operate between those points. The service was also advertised locally under the name 'The Diesel Rapide'. It left Crewe at 11:15, all stations to Chester, then leaving at 11:55 for Prestatyn (26 mins), Rhyl, Colwyn Bay (46 mins), Llan. Jct & Llandudno. It returned on the previously steam 13:45 through to Derby, to greatly accelerated timings. On the first day it was worked by 50480/59136/50248. Not having Llandudno on the indicators, they simply carried a 'B', arriving exactly on time. It was packed leaving Crewe, with standing in the van, and a steam releif had to be provided to cope with the Chester passengers. The service was scheduled for 2x3-car sets, but Crewe was short of stock.
DMUs had worked the Sunday service on the Millers Dale - Buxton branch for some months before taking over the weekday operations on the 7th Oct. '57.
On a Sunday excursion working from Manchester to Newcastle on the 3rd Nov. '57 were 50449/59157/50501 & 50437/59145/50489.
The Manchester - Hayfield/Macclesfield services saw 198,303 passengers for a sample month in '57, compared with 136,768 for the same month in '56, an increase of 61,535. On the Crewe - Stoke - Derby service at was 84,248 ('57) compared with 60,154 ('56), an increase of 24,094.
The through DMU working on Sundays from Stoke (dep. 16:00) to Rugby (arr 18:38 and return 18:50) was worked by 3-car sets, and on the 26th Jan. '58 it was the turn of 50437/59145/50489.
At the end of Jan. '58 the LMR preliminarily announced an extension of DMU services from Manchester (London Rd) to take in Stoke, with an hourly service between the two centres. The new workings were due to begin on the 3rd Feb., but were called off due to a mechanical fault found with the Class 104 bogies, just 48 hours before they were due to begin. About 40 sets were taken out of service, and the remedial work was expected to take five weeks and it was hoped the new services would begin in early March. Met-Camm sets were borrowed from the NER, and ten 2-6-4s obtained from Willesden.
They did start on the 3rd March '58. It made it possible to travel from Wolverhampton (High Level) at 09:06 and 18:23 to Birmingham New Street., via Bescot and Aston by trains which stopped at all stations, although there was not a similar service in the opposite direction.
The first four 3-car sets were re-allocated to the then new Buxton diesel depot on Feb 3, 1958 from Longsight, with more sets yet to come. They replaced the Derby Lightweights which could not cope with the demanding gradients and conditions of the 'Spa Line'. The 104s worked the line for almost 32 years, 31 years of which Buxton constantly had its own allocation of 104s. Buxton allocated driving cars were instantly recognisable with their painted white cab roofs, which complemented the green (and later blue) livery well.
Mid-58 saw 15 power-trailer sets delivered, 10 to the LMR at Stoke and 5 to the ER & NER at Bradford.
1958 also saw the 4-car sets delivered, a batch of 21 and a batch of 5, both to the NER, the first ones going to Darlington.
Four-car sets based at Darlington were introduced to York-Harrogate services on the 18th Aug. '58 to previous steam timings.
In service, the 104s worked over many routes on the BR network, covering most, if not all the DMU diagrams of their home depots. Throughout their lives being allocated to: Ayr, Bletchley, Buxton, Cambridge, Carlisle Kingmoor, Chester, Crewe North, Crewe South, Cricklewood, Darlington, Derby Etches Park, Eastfield, Hull Botanic Gardens, Hull Springfield, Leeds Neville Hill, Llandudno Junction, Longsight, Newton Heath, Norwich, Old Oak Common, Ryecroft, South Gosforth, Stoke, Stratford, Toton, Tyseley, York and Walsall Monument Lane. Of the routes worked by the class, the one they became synonymous with is the Buxton to Manchester Piccadilly 'Spa Line'.
They were also known to work to Skegness, on summer Saturday services from Manchester Piccadilly, as well as the occasional excursion.
Saturday May 6, 1989 saw the last official booked run of a 104 on the 'Spa Line' when N669 M53454 + M59187 + M53528 worked the 'Buxton 104 Farewell', an express run from Manchester Piccadilly to Buxton and return. Even after 'Sprinterisation' of the line on May 15, 1989, 104s still managed to work to Buxton on odd occasions - deputising for non available 'Sprinters'. The last occasion was on May 4, 1990 when CH610 M53447 + M53531 worked the 16:07 Manchester Piccadilly - Buxton and the 17:08 return to Bolton.
There were ten NSE liveried vehicles (eight DMBSs 53429/437/455/470/477/479/539/540 and two trailers 59163/206) The DMBSs were paired into four sets (L701 to L704). They emerged in NSE livery following overhaul at Doncaster Works in late 1988 and early 1989 (the last of the class to be treated) to work Barking to Gospel Oak services, until displaced by Class 115 sets, when they moved to the Thames Line. The two trailers were allocated to Bletchley and worked in various DMU sets.
One of the most unusual workings was the 'Mexican Bean' (53424 + 53434), which although allocated to Eastfield, Glasgow was stabled at Oban. It worked summer services from there to Crainlarich giving connections with Fort William trains. About once a week (normally Friday afternoons?) would see the set attached to the back of a loco-hauled service train to Glasgow for refuelling.