Thermostat - Low Gauge Reading/Poor Heater Output
NO: 07-02-95GROUP: Cooling System
DATE: Aug. 18, 1995
SUBJECT:
Low Heater Output
Poor Driveability
Low Temperature Gauge
Reading
MODELS:
1994 - 1995 (BR) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A V-10 (8.0L) ENGINE.
SYMPTOM/CONDITION:
Low heater performance, low temperature gauge reading or poor driveability due to engine not reaching operating temperature.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS) or the Scan Tool (DRB III) with the appropriate Diagnostic Procedure Manual, verify all engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin.
If the Powertrain Control Module (PCM) detects low engine coolant temperature, it will record a Diagnostic Trouble Code (DTC) in the PCM memory. If DTC 17 (Low Coolant Temperature) has been set, clear the code before performing the Repair Procedure
below.
PARTS REQUIRED:
1 53041078 Thermostat, 8.0L Engine
1 53005868 Gasket, Thermostat Housing (1994 Model Year Only)
REPAIR PROCEDURE:
This bulletin involves the replacement of the existing thermostat with a new thermostat.
1. Disconnect the negative battery cable at battery.
WARNING:
DO NOT LOOSEN THE RADIATOR DRAINCOCK WITH THE SYSTEM HOT AND PRESSURIZED. SERIOUS BURNS FROM THE COOLANT CAN OCCUR. ALLOW TIME FOR SYSTEM TO COOL AFTER COMPLETING DIAGNOSTICS PROCEDURES.
2. Drain cooling system until coolant level is below thermostat.
3. Remove the two support rod mounting bolts and remove support rod (intake manifold-to-generator mount). Figure 1
WARNING:
CONSTANT TENSION HOSE CLAMPS ARE USED ON MOST COOLING SYSTEM HOSES. WHEN REMOVING OR INSTALLING USE ONLY TOOLS DESIGNED FOR SERVICING THIS TYPE OF CLAMP, SUCH AS SPECIAL CLAMP TOOL NUMBER 6094. ALWAYS WERE SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS. A NUMBER OR LETTER IS STAMPED INTO THE TONGUE OF CONSTANT TENSION CLAMPS. IF REPLACEMENT IS NECESSARY, USE ONLY AN ORIGINAL EQUIPMENT CLAMP WITH A MATCHING NUMBER OR LETTER.
4. Remove upper radiator hose clamp and remove upper radiator hose at thermostat housing.
5. Disconnect the wiring connectors at both of the sensors located on thermostat housing. Figure 2
1994 M.Y Figure 2:
1995 M.Y Figure 3:
6. Remove six thermostat housing mounting bolts, thermostat housing, gasket and thermostat. Discard old gasket for 1994 M.Y. only. The 1995 M.Y. gasket is an integral part of the housing and is reusable. Discard old thermostat. Figures 2 & 3.
7. Clean mating areas of intake manifold and thermostat housing.
8. Check condition of the rubber thermostat seal located in the intake manifold. The thermostat should fit snugly in the rubber seal. If seal replacement is necessary, coat the outer (metal) portion of the seal with Mopar Gasket Maker (P/N 4318083). Install the seal into the manifold using special Seal Tool number C3995-A with Handle Tool number C-4171.
9. Install new thermostat (P/N 53041078) into recessed machined groove on intake manifold.
10. Install gasket (P/N 53005868) on intake manifold and over thermostat for 1994 Model Years only, Figure 2
11. Install housing-to-intake manifold bolts and torque to 25 N.m (220 in.lbs.).
CAUTION:
HOUSING BOLTS SHOULD BE TIGHTENED EVENLY TO PREVENT DAMAGE TO HOUSING AND TO PREVENT LEAKS.
12. Connect the wiring to both sensors.
13. Install the upper radiator hose and hose clamp to thermostat housing.
14. Install support rod.
15. Fill cooling system. Refer to refilling cooling system in the Ram Truck Service Manual (Publication Number 81-370-5108) page 7-38.
16. Connect negative battery cable to battery.
17. Start and warm engine. Check for leaks.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 07-40-05-91 0.9 Hrs.
Thermostat - Replace 1994-1995 (BR) with 8.0L Engines
FAILURE CODE: P8 - New Part