ILLUSTRATED STEERING SYSTEM BLEED PROCEDURE. GMC Truck Jimmy

********************************************************************** REVISION 12/09/93

THIS BULLETIN IS BEING REVISED TO ADD THE 1994 MODEL YEAR AND CHANGE THE ARTWORK. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE:

BUICK 93-3-5 4/04/93 CADILLAC T-93-76 5/12/93 CHEVROLET 93-146-3B 3/29/93 GM OF CANADA 93-3-102 5/05/93 OLDSMOBILE 2-93-59 5/14/93 **********************************************************************

SUBJECT: ILLUSTRATED STEERING SYSTEM BLEED PROCEDURE

MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS

THIS BULLETIN SUPERSEDES THE STEERING SYSTEM BLEED PROCEDURE IN CORPORATE BULLETIN 803201R.

THE STEERING SYSTEM IN 1994 AND PRIOR MODEL YEAR CARS AND LIGHT DUTY TRUCKS SHOULD BE BLED AFTER ANY OF THE FOLLOWING:

- A POWER STEERING COMPONENT IS REPLACED. - A FLUID LINE IS DISCONNECTED. - A CUSTOMER COMMENTS ON STEERING SYSTEM NOISE.

BLEEDING AIR FROM THE STEERING SYSTEM SHOULD BE DONE IN ORDER TO PREVENT PUMP DAMAGE, ENSURE PROPER OPERATION, AND TO ELIMINATE STEERING SYSTEM NOISE.

THE ATTACHED ILLUSTRATION PRESENTS A PICTORIAL ILLUSTRATION OF THE BLEED PROCEDURE. THIS NEW PROCEDURE REPLACES PREVIOUS STEERING SYSTEM BLEED PROCEDURES.

(NOTE TO TAS REVIEWER: BULLETIN CONTENT IS PRIMARILY PICTORIAL. THE FOLLOWING IS THE TEXT-ONLY PORTION.)

WHEN TO BLEED * AFTER ANY COMPONENT REPLACEMENT * AFTER DISCONNECTING FLUID LINE * IN CASE OF STEERING SYSTEM NOISE

WHY BLEED? * TO PREVENT PUMP DAMAGE * TO ENSURE PROPER SYSTEM OPERATION * TO STOP STEERING SYSTEM NOISE

BEFORE BLEEDING:

INSPECT STEERING SYSTEM. CHECK AND CORRECT AS NEEDED: * HOSES MUST NOT TOUCH ANY OTHER PART OF VEHICLE (STEERING SYSTEM NOISE COULD BE CAUSED BY HOSE TOUCHING FRAME, BODY OR ENGINE) * ALL HOSE CONNECTIONS MUST BE TIGHT (LOOSE CONNECTIONS MIGHT NOT LEAK BUT COULD ALLOW AIR INTO SYSTEM)

HOW TO BLEED: 1. SWITCH IGNITION OFF. 2. TURN STEERING WHEEL FULL LEFT. 3. FILL FLUID RESERVOIR TO "FULL COLD" LEVEL. LEAVE CAP OFF. 4. RAISE FRONT WHEELS OFF GROUND. 5. WITH ASSISTANT CHECKING FLUID LEVEL AND CONDITION, TURN STEERING WHEEL LOCK TO LOCK AT LEAST 20 TIMES. ENGINE REMAINS OFF. * ON SYSTEMS WITH LONG RETURN LINES OR FLUID COOLERS, TURN STEERING WHEEL LOCK TO LOCK AT LEAST 40 TIMES. * TRAPPED AIR MAY CAUSE FLUID TO OVERFLOW. THOROUGHLY CLEAN ANY SPILLED FLUID TO ALLOW FOR LEAK CHECK. * KEEP FLUID LEVEL AT "FULL COLD". 6. WHILE TURNING WHEEL, CHECK FLUID CONSTANTLY * NO AIR BUBBLES ARE ALLOWED. * FOR ANY SIGN OF BUBBLES, RECHECK CONNECTIONS. REPEAT STEP 5. 7. START ENGINE. WITH ENGINE IDLING, MAINTAIN FLUID LEVEL. REINSTALL CAP. 8. RETURN WHEELS TO CENTER. LOWER FRONT WHEELS TO GROUND. 9. KEEP ENGINE RUNNING FOR TWO MINUTES. 10.TURN STEERING WHEEL IN BOTH DIRECTIONS. VERIFY: * SMOOTH POWER ASSIST. * NOISELESS OPERATION. * PROPER FLUID LEVEL. * NO SYSTEM LEAKS. * PROPER FLUID CONDITION (NO BUBBLES, NO FOAM, NO DISCOLORATION) 11.IF ALL PROPER CONDITIONS APPLY, PROCEDURE IS COMPLETE. 12.IF ANY PROBLEM REMAINS, SEE "SPECIAL CONDITIONS".

SPECIAL CONDITIONS * FLUID - FOAM OR BUBBLES IN FLUID FLUID MUST BE COMPLETELY FREE OF BUBBLES. IN STEP 5, BE ALERT TO PERIODIC BUBBLES THAT COULD INDICATE A LOOSE CONNECTION OR LEAKY O-RING SEAL. - DISCOLORED FLUID (MILKY, OPAQUE OR LIGHT TAN COLOR) SWITCH IGNITION OFF. WAIT TWO MINUTES. RECHECK LOSE CONNECTIONS. REPEAT STEPS 7-10. IF CONDITION STILL EXISTS, REPLACE O-RING SEALS AND HOSECLAMPS. FILL SYSTEM AND REPEAT BLEED PROCEDURE.

* NOISE - PUMP WHINE OR GROAN

WITH ENGINE RUNNING, RECHECK HOSES FOR POSSIBLE CONTACT WITH FRAME, BODY OR ENGINE. IF NO CONTACT IS FOUND, FOLLOW EITHER METHOD BELOW TO COOL DOWN FLUID AND REPRESSURIZE SYSTEM.

METHOD 1: NORMAL COOL DOWN SWITCH ENGINE OFF. WAIT FOR SYSTEM TO COOL.

METHOD 2: PARTIAL FLUID REPLACEMENT SWITCH ENGINE OFF. USE A SUCTION DEVICE TO REMOVE FLUID FROM RESERVOIR. REFILL WITH COOL, CLEAN FLUID. INSTALL RESERVOIR CAP.

AFTER EITHER METHOD OF COOLING, START ENGINE AND ALLOW ENGINE TO COME UP TO OPERATING TEMPERATURE. IF NOISE PERSISTS, REMOVE AND REPLACE POWER STEERING PUMP. REPEAT BLEED PROCEDURE FOLLOWING PUMP REPLACEMENT.

SERVICE PARTS INFORMATION

P/N DESCRIPTION SIZE 1052884 POWER STEERING FLUID 16 OZ. 1050017 POWER STEERING FLUID 32 OZ.

12345866 COLD CLIMATE POWER STEERING FLUID 16 OZ. 12345867 COLD CLIMATE POWER STEERING FLUID 32 OZ.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

FIGURES: 1

Object Number: 75639 Size: FS

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.