B737-700
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 466; Flight Crew Type 8500
Time Pressure
ATC Issue All Types; Deviation - Altitude Undershoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance
Human Factors; Procedure
On descent into SJC we were given a late clearance for the RNAV Z 12R. We were just of few miles from the first waypoint. After reprogramming the approach we found ourselves high. Then ATC asked us to slow as much as practical and shortly slow to approach speed way early. We were simply unable to meet all their requests and meet our altitude restriction. We should have said unable; but in the thick of things we just threw out all drag devices and did the best we could.
B737-700 Captain reported being high on a crossing restriction on the RNAV Z Runway 12R approach into SJC after receiving a late ATC clearance.