bvcu, If I remember correctly, one problem was the bonded seals on the hydraulic component unions situated in the jet pipe areas, due to age and heat these would fail, producing a very high pressure hydraulic oil mist that ignited, causing fires in the jet pipe areas, also the tailplane gearbox was mag alloy.
One of the remedial actions we carried out was to wrap tape around the unions and secure with locking wire, so when the seals failed the oil merely dripped instead of spraying.
A Mk 53 landed at Tabuk with all gears up, the fuselage tanks absorbed the impact and the aircraft sustained minimal damage.