Hair line cracks in radiator capgasket

[Snowtiger]

After close examination of my cooling system and allot of reading the manual, I had pulled my water pump and changed my thermostat due to having no pressure in my cooling system. Exhausted all possibilities I did what should have been done first, I inspected my radiator cap and discovered three hair line cracks in the brass disc just under the cap, will this allow pressure to escape or does the rubber gasket seal everything at the bottom.

 

[M543A2]

The rubber gasket on the spring loaded part of the cap seals the pressure. Look for damage to it or to the surface down in the neck of the radiator it seals to.

 

[Snowtiger]

After changing the radiator cap with the correct replacement it appears that my water pressure is back up and I discovered I was placing a gauge on the wrong part of my cooling system to get the desired reading (lesson learned).

 

[someoldmoose]

Just requesting confirmation . . . You installed a coolant system PRESSURE GAUGE ? And if so, why? No disrespect, just curious.