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TSB 24-16-96

Vacuum System Contaminated By Engine Oil

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See also Recall #720, Extended Warranty Bulletin D-97-10

Date: Oct. 11, 1996

Models: 1995 - 1996 (BR) Ram Trucks

NOTE: THIS TECHNICAL SERVICE BULLETIN APPLIES TO VEHICLES EQUIPPED WITH THE 5.9L CUMMINS DIESEL ENGINE WITH ENGINE SERIAL NUMBERS (ESN) 56230585 THROUGH 56293178 OR 45232867 THROUGH 45360437. THESE ENGINES WERE INSTALLED IN VEHICLES BUILT BEFORE JUNE 1, 1996 (MDH 06-OI-XX).

Symptoms:

When the vacuum supply is contaminated by engine oil, any or all of the following may be customer concerns.

• Inoperative HVAC controls (i.e. airflow through defroster ducts only)
• Oil dripping from HVAC control head or the actuators onto the floor mat or carpet
• Speed control inoperative, slow to engage, or will not remain at a constant speed
• Unable to engageldisengage four wheel drive

Discussion:

Some Ram Trucks equipped with the 5.9L Cummins Diesel engine were produced without a check valve on the vacuum pump. Without the check valve, oil may enter the vehicle's vacuum system during extended engine idling conditions, accumulating in areas of the vacuum harness that are lower than the suction port on the vacuum pump. With the engine OFF, this accumulation of oil can be pulled through the vehicle's vacuum system, contaminate vacuum actuated devices, and eventually cause the device to malfunction.  

Diagnosis:

Any customer concern related to the previous Symptoms/Conditions should have the ESN inspected to verify whether or not the engine is within the suspect range. The ESN can be found on the Engine Data Plate, located on the left side of the timing cover housing, next to the oil fill tube (Figure 1). The ESN ( also known as the Engine No) is located to the right of the Timing TDC Specification.

If the ESN is within the suspect range, perform the following Repair Procedure. Also, a complete visual inspection of the vacuum system should be performed. Visually inspect the following vacuum actuated systems for contamination of engine oil at each vacuum port.

• HVAC Control Head
• HVAC Vacuum Harness
• Floor Duct Door Actuator
• Vent/Defrost Door Actuator
• Fresh Air Door Actuator
• Engine Vacuum Harness
• Speed Control Servo
• Speed Control Servo
• Vacuum Reservoir
• Speed Control Servo
• Vacuum Harness
• Four Wheel Drive Mode Switch
• Four Wheel Drive Axle Disconnect Motor
• Axle Disconnect Motor
• Vacuum Harness

Any portion of the vacuum system contaminated by engine oil should be repaired or replaced. Refer to the 1996 Ram Truck Service Manual (Publication No. 81-377-6108), Group 24 for servicing of the HVAC vacuum system, Group SH for servicing of the speed control system, and Group 3 for servicing of the front axle motor disconnect.

NOTE: ALL VACUUM ACTUATED COMPONENTS MUST BE INSPECTED FOR CONTAMINATION FROM ENGINE OIL AND PROPERLY SERVICED PRIOR TO RETURNING THE VEHICLE TO THE CUSTOMER.

Parts:

1    04883793AA   Check Valve Package

Repair:

This bulletin involves installing an external check valve onto the vacuum pump and replacing the main vacuum harness.

1.    Disconnect the 118 in. diameter HVAC vacuum supply hose from the in-line vacuum "T" connector on the main vacuum supply hose.

2.    Remove and discard the 318 in. main vacuum supply hose.

3.    Remove the vacuum nipple at the vacuum pump and discard the nipple.

4.    Install the check valve onto the vacuum pump. Tighten the check valve to 38 ft. lbs (52 Nm) of torque.

5.    Install hose clamp onto main vacuum supply hose. Install main vacuum supply hose onto the vacuum pump external check valve. Properly position and tighten the hose clamp.

NOTE: POSITION IN-LINE "T" CONNECTOR SO THAT THE HVAC PORT IS POINTING UPWARD BEFORE TIGHTENING THE CLAMP.

6.    Route the main vacuum supply hose over the top of the power steering hoses and tie strap the vacuum harness to the engine wiring harness located near the rear of the fuel injection pump.

7.    Install a hose clamp onto the main vacuum harness and connect the main vacuum harness to the power brake booster check valve. Tighten the hose clamp.

8.    Connect the 1/8 in. diameter HVAC vacuum supply hose to the in-line vacuum "T" connector on the main vacuum harness.

notes:

POLICY: Reimbursable within the provisions of the warranty. **

TIME ALLOWANCE:
Labor Operation No: 24-50-47-92 ................................. 0.5 Hrs
FAILURE CODE: PS - New Part

Subject:      CC TSB and Recall re: vacuum
Date:          Wed, 21 Jan 1998 15:18:46 -0500
From:         bob bergevin <bergevin@SLIC.COM>
To: .           cummins

-- Clarence Patton makes several comments that do need some further  relevant information.  It appears that his '96 Cummins 3/4 was recalled  for a "...vacuum check valve recall".  For everyone's information this  was Chry Co recall # 720, and is on file in every Dodge dealer's recall  file folder.  In addition a CC TSB (technical Service Bulletin) was  issued on October 11, 1996, and carries TSB # 24-16-96 with much of the  same information of recall 720, and the recall notice made reference to  the TSB that preceded it.  The TSB identified the series of vehicles  involved, (those with engine serial #'s 56230585 thru 56293178 or from  45232867 thru 45360437 [2 groups as there are 2 Cummins assembly plants  for the 5.9L model] some 190,000 engines) installed in vehicles built  BEFORE June 1, 1996 (or 0601xx as displayed on the driver door jamb  decal listed MDH, or month day and hour of final assembly).

On page three of the TSB in caps, "...ALL VACUUM ACTUATED COMPONENTS  MUST BE INSPECTED FOR CONTAMINATION FROM ENGINE OIL AND PROPERLY  SERVICED PRIOR TO RETURNING THE VEHICLE TO THE CUSTOMER."

The TSB was published first, and the recall to inspect and install the  check valve was made during the summer /fall of 1997 almost 1 year AFTER  the TSB.  List member Patten writes, "...the dealership finally  concluded that all the vacuum hose connections were contaminated...and  had to be replaced.  As the service department explained, CC did the  check valve recall, but did not make provisions to check other rubber  components throughout the vacuum system."

NOT TRUE - both the TSB and the Recall notice CLEARLY and IN CAPS, stated  to "...be inspected and ...properly serviced prior to returning...to the  customer."  Find your dealer, find his Recall notice file, and read  #720, and find the TSB #24-16-96 and read that one.  Your service  department did not read the TSB and probably didn't read much of the  Recall notice.  If you spent your $30,000 +/- with him for your Ram,  find another dealer who cares how he supports his customers.  Mine took  mine in and spent almost 10 hours replacing all the vacuum servos in the  vehicle as they were all contaminated.  No easy task as they are mostly  behind the dash for the HVAC system.

Owners of a used Cummins/Dodge built prior to June 1, 1996  (MDH 0601xx  on the drivers door jamb decal, look for it carefully it also has the  recommended tire pressures and other loading info on it as well) can  check to see if their vehicle has had any or all the recalls done and  who did them by going to their Chrysler dealer with their VIN and asking  the service department to run their VIN through function 14 on the DIAL  System to Chrysler.  The resulting summary will give a wealth of  information regarding warranty info remaining, and recall history  according to the CC records.  If it ain't on there, it was never done.

Remember, a recall is done to correct a safety aspect of the vehicle and  requires notification of all affected in the group.  A TSB is issued to  correct a technical problem in a vehicle or procedure that has been  found that may affect the operation and satisfaction of a vehicle by its  operator. TSB's are not usually used to locate every model that MAY have  that problem.  Each is handled on a need-to-find-out basis. TSB's are  located by making an inquiry from the VIN for a specific problem.  They  are also sent to the service departments and printed in a bound volume  the dealer has somewhere in backfile form.

 Bob Bergevin