BANGOR — Insufficient brake fluid in the antique braking system on the 1930 McCann Pumper failed to stop the firetruck during the annual Fourth of July parade and is being blamed for a fatal collision that took the life of a Holden man.

“This inspection and testing of the fire truck concluded that there was a total loss of pressure at the master cylinder of the hydraulic braking system … due to insufficient amount of brake fluid and poor quality brake fluid which introduced air into the brake system,” the report released by Bangor Police Department on Thursday states.

The 83-year-old water pumper, driven by off-duty Bangor firefighter Patrick Heathcote, 29, of Levant, failed to stop on Water Street after the parade route was diverted because of a standoff on Park Street about four blocks away.

Heathcote could not stop the heavy fire apparatus that struck a vintage 1941 John Deere tractor driven by antique vehicle lover Wallace Fenlason, 63, of Holden, who fell into the path of the firetruck and was killed, the report states.

A four-member team from the Maine State Police crash analysis unit based in Augusta, led by Sgt. Darren Foster, conducted the “vehicle autopsy” two weeks ago on the 1930 McCann Pumper that is kept at the Hose 5 Museum on State Street.

“It was a challenge because of its age,” Foster said last week.

He later added the hydraulic braking system on the 83-year-old pumper has the same mechanics as those used today.

The crash analysis unit inspection was conducted on July 19 at Eastern Maine Community College, with Bangor police Officer Jim Dearing in attendance.

Dearing did the crash reconstruction report and is leading the investigation. A supplemental report by Detective Cliff Worcester also was filed.

The historic fire apparatus is owned by the city and, according to a 1984 agreement, is leased to a group called the McCann Committee, made up of firemen who were on the force at the time.