Trouble description: MAC aftercooler water side gaskets rupturing frequently. Our vessel is fitted with MAC

Trouble description: MAC aftercooler water side gaskets rupturing frequently.

Our vessel is fitted with MAC (Yanmar C 370), having 2 pistons per compressor. Vessel is 20+ yrs old.

Our compressors have a history of aftercooler gasket rupture of air side. Lately its happening more frequently.

We are thinking of slightly over tightening the bolts but afraid of damaging the threads on body which has already happened on few bolts of other compressor.

Can there be a different problem than just tightness of cooler cover on gasket. Please share observations or ideas if anyone has faced similar issue.

Observations:

1. Intercoolers are pressure tested and ok.
2. For MAC 1 water side gasket ruptured a few times.
3. For MAC 2 till now only air side gasket ruptures with air leaking outside cover (without having water entering air side).
4. Present gaskets onboard seems to be thicker, not from original makers.

Parameters (Normal/Present): All operating parameters including pressures are same as before. Nothing abnormal.

Update1: For MAC 1 We doubted uneven tightness as some of the bolts were loose. We have made a jacking arrangement to provide even tensioning and now it's holding..

MAC 2 all threads are ok but still facing air side gasket rupture. (note gasket is not original make)