Manchester Evening News revealed the time lost in handovers - the period between the ambulance arriving at the hospital and the patient's care being transferred to medics so the crew can leave - is the equivalent to two paramedics waiting for nine full 12-hour shifts.
The 104 hours, lost at Manchester Royal Infirmary, North Manchester General and Wythenshawe Hospital, account for the excess outside the 15-minute target that handovers should take.
It represents time that could be spent responding to other 999 calls. The Manchester Evening News had previously asked all the hospital trusts and NWAS for these figures but were told by the ambulance service to submit a Freedom of Information request - which could take up to three months.
Read more on manchestereveningnews.co.uk