🧪 ACDelco GM RC107 Radiator Surge Tank Cap - Original Equipment, 16 PSI Review

Stops a mysterious coolant leak on my 2011 DTS. The pressure was released via the cap O-ring and the coolant drained from the tanks while driving. If you slowly remove the cap after a long ride and don't hear any pressure relief, it's time for a new cap. This is actually an 18psi cap, not the 16psi cap as advertised.

My 2008 Corvette upper radiator hose kept breaking due to improper pressure. The radiator cap must not relieve pressure, it MUST vent. My hose collapsed because of the vacuum. This cap is the exact same part that came with the C6 Corvette from the factory. Works great and no more problems with my hose.

If you want to know if your cap needs replacing, remove the old cap and check the O-ring. If the o-ring is flush with the stem in the cap, you will need to replace it. When I compared the old and new baseball caps, the alignment in the new baseball cap is well rounded and billowy. This is of great importance to maintain the correct pressure in the system.