REVISED INSTRUCTIONS HALF FILLED CATALYTIC CONV.

A new instruction sheet for half filled catalytic converters has been released for use with Cadillac 4.1L V-8 engine applications. This instruction sheet, part number 25100411, dated January 16, 1985 applies to half-filled catalytic converter kits, service part numbers 25057007 and 25056984 when used on a vehicle with a 4.1L V-8 engine (VIN engine code "8".) A copy of this new instruction sheet is attached and supersedes previously dated instruction sheets.

Half-filled catalytic converter kit part number 25057007 supersedes half-filled converter kit part number 25056984 and the factory filled catalytic converter, part number 25056623. The converter kit contains a half-filled (upper bed filled) converter, a fill hole plug, and an instruction sheet(s). The kit part number was changed to allow a number of Cadillac, Oldsmobile, and Buick applications to share a common half-filled catalytic converter. The lower bed catalyst and instructions for the Cadillac 4.1L V-8 application differs, however, from Oldsmobile and Buick applications. The lower bed catalyst and instructions for the Cadillac 4.1L V-8 also differ from the lower bed catalyst and instructions for catalytic converter replacement on a Cadillac with a 4.1L V-6 engine manufactured at a GM plant operated by Buick Motor Division.

Some early production converters, kit part numbers 25056994, and 25057007 may not include the new instruction sheet. The attached copy of the new instruction sheet should be duplicated and used in these cases.

Converter kits with part numbers 25056994 and 25057007 may also contain an instruction sheet, part number 25057962, which applies only to 4.3L V-6, 5.0L V-8, and 4.1L V-6 engines. Instruction sheet 25057962 should not be used with converter kits 25056984 and 25057007.

When replacing a catalytic converter, use the appropriate instruction sheet as listed below. Instruction Application Sheet Part No. ----------- -------------- 1982-1985 Cadillacs with 4.1L V-8 Engine 25100411 (VIN code "8")

1981-1982 Cadillacs with 4.1L V-6 Engine 25057962 (VIN code "4")

INSTRUCTIONS FOR CADILLAC 4.1L V=8 ENGINE VIN ENGINE CODE 8

CAUTION

-------- Allow catalytic converter to cool before handling.

Lower bed catalyst beads contain platinum and palladium and, additionally, may be finely coated with lead compounds. Therefore, suitable precautions should be taken to minimize dust generation during replacement procedure.

A. Applicable OSHA standards should be reviewed.

B. Prior to bead removal, pour water into the catalytic converter as described in Step Two.

C. Use of suitable dust mask, rubber gloves and safety glasses is recommended when handling catalyst beads.

Important - Determine which procedure to use as follows:

All 1983-1984 Vehicles use Procedure B. 1982 Vehicles use procedure B if: -------------------------------------- 1. Converter is expanded (greater than four and one-half inches thick), or

2. Converter is externally damaged, or

3. Converter catalyst is contaminated (by lead, silcone, etc.), and causes emission test failure or,

4. Converter is restricted as diagnosed in Bulletin 85-35 section 6E, or

5. Converter had part number 25056623 or 25056894 stamped on underside of the flange near the outlet end.

1982 Vehicles which meet none of the five conditions listed above use Procedure A.

Procedure A

1. Remove catalytic converter from vehicle using procedure described in appropriate service manual.

2. Stand old converter upright on inlet and pour (2) two 8 ounce cups of water in outlet to control dust.

3. Remove lower bed fill plug and pour catalyst beads into Pan J-34155-2. Pound converter belt flange if necessary to dislodge beads.

4. Using sifting pan J-34155-1, sift out usable, broken beads (smaller than half size). Return remaining, reusable beads (half size and larger) to pan J-34155-2 and save for step 6.

5. Prop new converter at a 45 DEG angle with lower bed fill hole up. Insert funnel J-34155 securely into fill hole (tap gently with hammer if necessary.)

6. Pour reusable lower bed beads (reference step 4) into new converter, tapping converter belt flange with rubber mallet while filling so beads will settle. If lower bed is not full, top off using catalyst beads in catalyst package P/N 25100011.

7. Lay converter on a flat surface and insert fill plug into lower bed fill hole. If outer rim of fill plug does not seat flat against converter cover, remove enough beads so it does.

8. Insert fill plug expander tool J-34118 into fill plug and tighten to a torque of 35 Lb.ft. Making sure plug outer rim remains seated against converter cover.

9. Install new converter on vehicle using procedures described in appropriate service manual.

Procedure B

1. Remove catalytic converter from vehicle using procedures described in appropriate service manual.

2. Prop new converter at a 45 DEG angle with lower bed fill hole up. Insert funnel J-34155 securely into fill hole (tap gently with hammer if necessary)

3. Pour catalyst in lower service kit P/N 25057558 into lower bed of new converter. Tapping converter belt flange with rubber mallet while filling so beads will settle.

4. Lay converter on flat surface and insert fill plug into lower bed fill hole. If outer rim of plug does not seat flat against converter cover remove enough beads so does.

5. Insert fill plug expander tool J-34118 into fill plug and tighten to a torque of 35 Lb-Ft. Making sure plug outer rim remains seated against coverter cover.

6. Install new converter on vehicle using procedures described in appropriate service manual.

Parts Information

Removed parts are to be retained in accordance with the current Service Policies and Procedures Manual.

Catalyst packages (lower bed beads) are to be obtained from GMWDD using the following part numbers:

Catalyst Package

(Lower Bed Top-off Catalyst) 25100011

Lower Service Kit Package (Lower Bed Catalyst) 25057758

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.