What was found
CLT FLT 1729 EN ROUTE PHL TO CLT. C AUTOPILOT COMMANDED AN ABRUPT INCREASE IN PITCH APPROACHING 30 DEGREES & RESULTING RAPID LOSS OF AIRSPEED AT 1400 FT AFTER TAKEOFF, IMMEDIATELY AFTER ENGAGING. MX PERFORMED FAULT ISOLATION PROCEDURES, NO TROUBLE FOUND. REPLACED CTR FCC, GND TESTED OK. SHOP FINDINGS, UNIT FUNCTIONALLY TESTED GOOD. HOWEVER, FOUND A23A1C25 CRACKED & LEAKING. REPLACED A23A1C25. AS A PRECAUTION, ALSO REPLACED A23A1C22, A23A1C23, A23A1C24, A1AC125, A1A1K1, A1A1K2, A1A1K3 & A1A1K4.