ARMY TM 9-2815-252-24 AIR FORCE TO 38G1-92-2 c. Start engine and record reading on manometer. d. Stop engine, disconnect manometer and install oil dipstick. e. If water manometer is not available, place a piece of thick paper over the oil fill opening.  If crankcase vacuum retains paper, vacuum is good. FIGURE 3-1.  Locally Manufactured Water Manometer Section IV.  INTAKE AND EXHAUST SYSTEM MAINTENANCE 3-6.   INTAKE MANIFOLD. 3-6.1. Removal. a. Remove air intake piping.  Refer to end item maintenance manual. b. Tag and disconnect electrical leads from heater plugs (1, FIGURE 3-2). c. If damaged or defective, remove heater plugs (1) from manifold. d. Remove four bolts (2), four washers (3), intake manifold (4), and two gaskets (5).  Discard gaskets (5). e. Cover all openings. 3-6.2. Inspect and Measure. a. Inspect manifold for cracks, corrosion, or other damage.  Replace if damaged. b. Inspect attaching hardware for damage.  Replace if damaged. c. Inspect heater plugs for damage. d. Set multimeter for ohms and test heater plugs.  Normal reading is 4 to 5 ohms.  Zero resistance indicates a shorted heater and a high reading indicates an open heater. 3-6.3. Installation. a. Remove all covers installed during removal. b. Install new or tested heater plugs (1, FIGURE 3-2) in manifold (4). c. Clean intake manifold (4) and cylinder head mating surfaces of any traces of old gasket. d. Position two new gaskets (5) and intake manifold (4) on cylinder head. e. Install four washers (3) and four bolts (2).  Tighten bolts to 78 in-lbs (8.8 Nm). f. Connect electrical leads to heater plugs.  Refer to end item maintenance manual.  Remove tags. g. Install air intake piping.  Refer to end item maintenance manual. Change 3 3-15