Abstract: A normally closed check valve has an ephemeral seal on the entry side thereof which blocks fluid flow through the check valve at pressure differentials acting across the check valve which would normally open the check valve and cause fluid flow to occur through the check valve. The ephemeral seal is a high viscosity material which when heated to a temperature well above the normally encountered ambient temperature will become of sufficiently low viscosity to flow from the check valve entry and be removed from blocking the opening of the check valve. The ephemeral seal is usually so heated by operation of the mechanism in which the check valve and ephemeral seal are installed, such operation normally creating sufficient heat to heat the ephemeral seal to that temperature which causes it to be of sufficiently low viscosity to flow away from the check valve entry. The mechanism disclosed which uses the check valve and a preferred embodiment of the ephemeral seal is a disc brake caliper assembly.