Difficulty was experienced in carrying any large quantity of parcels and prams which rural customers were accustomed to taking with them. Despite the fact that in the first year of operation, the railbuses reduced operating costs by £66,000 only one branch was proving a profitable venture and the services as a whole were still losing about £4,000 a year. Traffic on the Braintree branch soon proved too much for the railbus, which was replaced by a two-car set. The story was not so good on the other branches. The Colne Valley line closed on the 1st Jan 1962 and the Mildenhall branch from the 18th June 1962. At the time there were thoughts about transferring some of the vehicles to Parkeston Quay for workman's trains. Services on the Audley End - Saffron Walden - Bartlow and Witham - Maldon branches survived another two years until the 7th September 1964.

In May 1965 79964 was sent to the NER for trials on the Haltwhistle - Alston branch, and was joined by 79963 three months later. It returned south soon after but 79964 remained until early '66, the trials unsuccessful. Fuelling could only be done at South Gosforth, it could not haul parcels vans, and the winter brought more trouble including with it's heating. After a period in store 79961/4 were transferred to Buxton (LMR) in July '66 where they replaced the Park Royal Railbuses on the Millers Dale services. They were withdrawn one year later.

79960 W 11/66. To Preservation
79961 W 8/67. Scrapped at Rotherham in 1968. Some spares were salvaged for K&WVR vehicles.
79962 W 11/66. To Preservation.
79963 W 11/66. To Preservation
79964 W 4/67. To Preservation