ENGINE DIAGNOSTIC TEST PROCEDURES Section 6 • CRANKCASE PRESSURE 400 Series On-Highway (with Robert Bosch MW Pumps) FROM FORM NO. CGED-365 CRANKCASE PRESSURE* 11 A. LATE MODEL TURBO WITH VALVE COVER MOUNTED BREATHER: 1.Measure @ breather tube with orifice restrictor tool, SE-4039. 2.Measure - High idle (no load) RPM. INSTRUMENT GUIDELINE DATA‚ 1st CHECK 2nd CHECK WATER MANOMETER OR MAGNAHELIC GAUGE *Engine must be at normal operating temperature. p Refer to "Performance Data Guidelines", in this Section. 1. Measure crankcase pressure, using breather restrictor tool SE-4039, as follows:  (See Figure 24). a. Park vehicle on level ground. b. Insure  breather  tube  and  element  are  free  of dirt. c. Insure engine oil level is not above full mark. d. Connect a line from the restrictor tool to a water manometer or magnehelic gauge (SE2239). e. Run engine at high idle (no load) RPM. f. Test  must  be  made  with  engine  specified  oil and    water    temperatures    as    shown    in    the PERFORMANCE   DATA   GUIDELINES,   at   the end of this section. g. Record crankcase pressure in 1st check box on Form CGED-365. h. Crankcase pressure guidelines are as follows: •T/DTI-466C  .  .  .  .  .5.5 in. H20 (max.) IMPORTANT DO     NOT     PLUG     THE     BREATHER     TUBE DURING THE CRANKCASE PRESSURE TEST AS   RESTRICTING   THE   TUBE   CAN   CAUSE CRANKSHAFT AND TURBOCHARGER SEALS TO LEAK. 2. Excessive  crankcase  pressure  with  oil  consumption trend data indicates: a. Badly worn or broken rings and/or b. Badly worn or scored cylinder sleeves. 3. Review    the    recorded    results    of    the    crankcase pressure test.  If there is any difference between the guideline  data  and  the  1st  check  box,  correct  as necessary and repeat the test. 4. If results obtained during the above tests are  within guidelines, engine operation is satisfactory. Figure 24.  Crankcase Pressure Test CG ES-240-4 Printed in United States of America Page 32