What was found
AFTER TAKEOFF, SMELLED A PETROLEUM TYPE ODOR. CLIMB OUT DURING DEPARTURE, TRIED BLEED AIR FUNCTIONS TO ISOLATE THE ODOR. TURNED ON HEAT IN CABIN AND SAW SMOKE COMING FROM VENTS. RETURNED TO AIRPORT. TURNED OFF HEAT AND SMOKE STOPPED. NO INDICATION OR IMMEDIATE THREAT OF FIRE. LANDED WITHOUT INCIDENT AND TAXIED INTO THE RAMP. DETERMINED HYDRAULIC REGULATOR TO BE LEAKING. REPLACED HYDRAULIC REGULATOR. VERIFIED NO LEAKS AND NO SMOKE ON POST MX OPS CHECKS.