The Littlest Hobo: Series 6 (1985)

Hobo lends moral support to a boy in a new school who wants to try out for the track team but is rejected by his new peers...The Hobo discovers a senile veteran who is the custodian of an unexploded bomb. He is able to bring it to the attention of a nearby military base, but the stakes are raised when it's discovered that it is near an abandoned munitions dump...