Somebody really cranked down on those bolts.
The 4 corner bolts are to keep A/C Unit attached to roof and apply enough force to make roof gasket seal.
Over tightening can warp roof, crush gasket and damage A/C pan.
As you have found out. Wide washers will help keep already damaged area from more damage. New gasket as it has been crushed with hold down bolts that tight.
Roof gasket should only be compressed to 1/2 of thickness. Hold down bolts are to be 'snug'....finger tighten then just slight snug up with wrench.
If you have an 'Pound-INCH' torque wrench they are torqued to 20 pounds-inch
Not 20 pounds-foot -----that would be like how tight you would tighten a 1/4" standard bolt using a box end wrench and hand cranking it tight.
20 pound-inch is just a slight tweak after finger tight.
NOW don't confuse the 'terminology'
Pounds-Foot (pounds-inch) are measurements of 'torque'
Foot-Pounds are a measurement of 'energy'
Lots of folks will use 'foot-pounds' when talking about torque just like 'tank vs cylinder' for propane and think they are the same.......but they aren't.
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31