A camshaft phaser (12, 212) for use with an internal combustion engine (10, 210) for controllably varying the phase relationship between a crankshaft and a camshaft (14, 214) in said internal combustion engine (10, 210), said camshaft phaser (12, 212) comprising: an input member (18, 218) connectable to said crankshaft of said internal combustion engine (10, 210) to provide a fixed ratio of rotation between said input member (18, 218) and said crankshaft; an output member (20, 220) connectable to said camshaft (14, 214) of said internal combustion engine (10, 210) and defining an advance chamber (42, 242) and a retard chamber (44, 244) with said input member (18, 218); a valve spool (28, 228) coaxially disposed within said output member (20, 220) such that said valve spool (28, 228) is rotatable about an axis (16, 210) relative to said output member (20, 220) and said input member (18, 218), said valve spool (28, 228) defining a supply chamber (98, 298) and a vent chamber (100, 300) with said output member (20, 220); an actuator (118, 318) which rotates said valve spool (28, 228) in order to change the position of said output member (20, 220) relative to said input member (18, 218) by 1) supplying oil from said supply chamber (98, 298) to said advance chamber (42, 242) and venting oil from said retard chamber (44, 244) to said vent chamber (100, 300) when retarding the phase relationship of said camshaft (14, 214) relative to said crankshaft is desired and 2) supplying oil from said supply chamber (98, 298) to said retard chamber (44, 244) and venting oil from said advance chamber (42, 242) to said vent chamber (100, 300) when advancing the phase relationship between said camshaft (14, 214) relative to said crankshaft is desired; and a recirculation check valve (78, 278) which is displaceable axially between 1) an open position which allows oil to flow from said vent chamber (100, 300) to said supply chamber (98, 298) and 2) a closed position which prevents oil from flowing from said supply chamber (98, 298) to said vent chamber (100, 300) and, wherein the recirculation check valve opens into said supply chamber. an input member (18, 218) connectable to said crankshaft of said internal combustion engine (10, 210) to provide a fixed ratio of rotation between said input member (18, 218) and said crankshaft; an output member (20, 220) connectable to said camshaft (14, 214) of said internal combustion engine (10, 210) and defining an advance chamber (42, 242) and a retard chamber (44, 244) with said input member (18, 218); a valve spool (28, 228) coaxially disposed within said output member (20, 220) such that said valve spool (28, 228) is rotatable about an axis (16, 210) relative to said output member (20, 220) and said input member (18, 218), said valve spool (28, 228) defining a supply chamber (98, 298) and a vent chamber (100, 300) with said output member (20, 220); an actuator (118, 318) which rotates said valve spool (28, 228) in order to change the position of said output member (20, 220) relative to said input member (18, 218) by 1) supplying oil from said supply chamber (98, 298) to said advance chamber (42, 242) and venting oil from said retard chamber (44, 244) to said vent chamber (100, 300) when retarding the phase relationship of said camshaft (14, 214) relative to said crankshaft is desired and 2) supplying oil from said supply chamber (98, 298) to said retard chamber (44, 244) and venting oil from said advance chamber (42, 242) to said vent chamber (100, 300) when advancing the phase relationship between said camshaft (14, 214) relative to said crankshaft is desired; and a recirculation check valve (78, 278) which is displaceable axially between 1) an open position which allows oil to flow from said vent chamber (100, 300) to said supply chamber (98, 298) and 2) a closed position which prevents oil from flowing from said supply chamber (98, 298) to said vent chamber (100, 300) and, wherein the recirculation check valve opens into said supply chamber.