Hello - noobie here in need of GM brake expertise

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  #1  
Old 04-11-08, 02:21 PM
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Hello - noobie here in need of GM brake expertise

Greetings everyone. I'm a bit confused on GM's brake repair procedures for my 1995 and 1996 Suburbans. Both originally came with the composite rotors. The dealer replaced the rotors on my 1995 in the 90k range with non-composite ACDelco replacements (noise abatement) but cut the rotors on the 1996 (third cut) about 95k. Right front rotor on the 1996 then separated into two (hub and disc) while I was braking on the highway about 20k miles later.

Dealer says it happened because of heavy corrosion where the hub is joined to the disc. Wouldn't that be a normal area to check on the composites when replacing the pads during a routine state inspection? But, how would you quantify 'badly corroded'? I can't think of any tool that would let you know. I still have my original service manuals but they don't address corrosion at all.

I ask because in digging around on the net, the 88-92 Suburbans were recalled because of corrosion at that hub/disc joint. Same part numbers on the 1995 and 1996 as earlier models. Anyone know what changed between 1992 and 1996 in either maintenance procedures, manufacturing, or design? I can't find any TSBs or other documentation relating to the 1995-6 models.
 
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  #2  
Old 04-11-08, 05:00 PM
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Did you get to keep the bad parts and/or inspect them? You suspicious that when they cut the third down, 20k earlier, that that allowed weakness and then splitting?
 
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Old 04-11-08, 05:14 PM
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Originally Posted by ecman51` View Post
Did you get to keep the bad parts and/or inspect them? You suspicious that when they cut the third down, 20k earlier, that that allowed weakness and then splitting?
Kept the rotor. It is wafer thin where the hub and disc used to meet - makes a good knife. Where it separated isn't part of the disc surface so I don't think cutting it would even touch it. Just don't see how it could get that thin. Dunno. I've read some other opinions that say cutting is bad because it reduces the disc's ability to get rid of heat which then can compromise the joint though. Opinions still seem to vary.
 
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Old 04-11-08, 05:29 PM
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We'll have to let some of the pros weigh in on this one. I just thought I'd be the catalyst, as no responses. Friday can be bad here sometimes. I think people go out for a fish fry maybe.
 
  #5  
Old 04-11-08, 07:57 PM
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Just to give you an idea on Composite Brake Rotors, unclear if related to 96

#92C34: CAMPAIGN: COMPOSITE BRAKE ROTOR CORROSION SEPARATION - (Sep 1, 1993)


Subject: PRODUCT SAFETY CAMPAIGN 92C34 COMPOSITE BRAKE ROTOR SEPARATION

Model and Year: 1988-92 K1500 & K2500 TRUCKS AND 1990-92 L VANS (VEHICLES CURRENTLY REGISTERED IN SEVERE CORROSION STATES ONLY)

To: All Chevrolet Dealers

The National Traffic and Motor Vehicle Safety Act, as amended, provides that each vehicle which is subject to a recall campaign of this type must be adequately repaired within a reasonable time after the owner has tendered it for repair. A failure to repair within sixty (60) days after tender of a vehicle is prima facie evidence of failure to repair within a reasonable time.

If the condition is not adequately repaired within a reasonable time, the owner may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation.

To avoid having to provide these burdensome solutions, every effort must be made to promptly schedule an appointment with each owner and to repair their vehicle as soon as possible. As you will see in reading the attached copy of the letter that is being sent to owners, the owners are being instructed to contact the Chevrolet Customer Assistance Center if their dealer does not remedy the condition within five (5) days of the mutually agreed upon service date. I f the condition is not remedied within a reasonable time, they are instructed on how to contact the National Highway Traffic Safety Administration.

DEFECT INVOLVED

General Motors has determined that a defect which relates to motor vehicle safety exists in certain 1988-92 Chevrolet K1500 and K2500 series trucks and 1990-92 All-Wheel-Drive Astro van model vehicles located in severe corrosion states (see Vehicles Involved section). These vehicles have composite front brake rotors. If severe corrosion were present, the stamped-steel center section of the composite front brake rotor could separate from the cast outer rotor resulting in a total loss of braking capability of the affected wheel. Partial loss of front braking at a time when stopping distance is at a minimum could result in a vehicle crash without prior warning.

Severe corrosion of this type is time related not mileage related, therefore, 1988 owners involved in this campaign will be notified first, then additional model year vehicle owners will be notified sequentially as parts become available.

Since this potential failure is time related, there will be no requirement for visual inspection prior to the owner receiving his owner notification nor any reason to reimburse for previous repairs related to normal maintenance.

To prevent this condition from occurring, dealers are to replace both front brake rotors with rotors having a corrosion protective coating. Replacement of the brake linings is considered a normal maintenance item. Due to normal wear, it is possible that the brake linings will need to be replaced. Replacement of the brake linings, if necessary, should be done at the owner's expense.

VEHICLES INVOLVED

Involved are 1988-92 Chevrolet K1500 models, 1988-92 K2500 models with C5Z GVW rating option, and 1990-92 All-Wheel-Drive Astro van models which operate in severe corrosion states and were built within the following VIN breakpoints:

PLANT YEAR MODEL PLANT CODE FROM THROUGH ------------------------------------------------------------------------ 1988-91 K1500 & Pontiac East "E" SOP EOP K2500 W/C5Z

1988-91 K1500 & Fort Wayne "Z" SOP EOP K2500 W/C5Z

1988-91 K1500 & Oshawa "1" SOP EOP K2500 W/C5Z

1992 K1500 & Pontiac East "E" SOP NE159588 K2500 W/C5Z

1992 K1500 & Fort Wayne "Z" SOP NZ128562 K2500 W/C5Z

1992 K1500 & Oshawa "1" SOP N1166649 K2500 W/C5Z

1992 K1500 & Janesville "J" SOP NJ302199 K2500 W/C5Z

1990 L Van Baltimore "B" SOP EOP

1991 L Van Baltimore "B" SOP EOP

1992 L Van Baltimore "B" SOP NB128944

Severe corrosion states are as follows:

Connecticut Michigan Pennsylvania Illinois New Hampshire Rhode Island Indiana New Jersey Vermont Maine New York Wisconsin Massachusetts Ohio

Involved vehicles have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle Identification Number, owner name and address data, and will be furnished to involved dealers at a later date (see special cover letter). Owner name and address data furnished will enable dealers to follow-up with owners involved in this campaign.

These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.

OWNER NOTIFICATION

Owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of owner letter included with this bulletin). Owner mailings will be phased starting with 1988 model year vehicles beginning November 8, 1993.

DEALER CAMPAIGN RESPONSIBILITY

All unsold new vehicles in dealers' possession and subject to this campaign must be held and inspected/repaired per the service procedure of this campaign bulletin before owners take possession of these vehicles.

Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.

Owners of vehicles recently sold from your new vehicle inventory with no owner information indicated on the dealer listing, are to be contacted by the dealer, and arrangements made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owners letter accompanying this bulletin. Campaign follow-up cards should not be used f or this purpose, since the owner may not as yet have received the notification letter.

In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

PARTS INFORMATION:

Following the initial preshipments (see cover letter), parts required to complete this campaign may be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a "C.I.O." order with no special instruction code, but on a advise code (2).

Part Number Description Quantity/ Vehicle ------------------------------------------------------------------------ 15984034 Front Brake Rotor Kit (Contains 2 Rotors) 1 - For 1988-91 K1500 WITHOUT C5G GVW Rating, All 1992 K1500, And 1988-91 K2500 WITH C5Z GVW Rating

15984033 Front Brake Rotor Kit (Contains 2 Rotors) 1 - For 1988-01 K1500 WITH C5G GVW Rating

01052542 Delco Supreme II Brake Fluid As Needed (4 Gallon Can)

SERVICE PROCEDURE

1. Drain 2/3 of brake fluid from master cylinder.

2. Raise vehicle.

3. Remove both front wheel assemblies.

4. Remove and support BOTH front brake calipers.

5. Remove both front brake rotors.

6. Install NEW front brake rotors.

7. Reinstall both front calipers torquing bolts to 51 Nm (35 lb. ft.)

8. Reinstall front wheels torquing nuts to 160 Nm (120 lb. ft.) for K trucks or 140 Nm (100 lb. ft.) for L Vans.

9. Lower vehicle.

10. Refill master cylinder with new brake fluid (using Delco Supreme II brake fluid or equivalent DOT-3 brake fluid).

11. Install Campaign Identification Label.

NOTICE: Due to normal wear, it is possible that the brake linings will need to be replaced. Replacement of linings, if necessary should be done at the owner's expense.

CAMPAIGN IDENTIFICATION LABEL

Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner. Additional "Campaign Identification Labels" can be obtained from DAC.

Apply "Campaign Identification Label" only on a clean, dry surface.

CLAIM INFORMATION

Submit a Product Campaign Claim with the information indicated below:

* FAILED PARTS CC-FC LABOR LAB OTH REPAIR PERFORMED PC PART NO. ALLOW OP HRS HRS -----------------------------------------------------------------------

Replace Both Front Brake Rotor - 2 15984034 ** SK-00 V8160 0.6 0.1 K 1500-2500 Trucks

Replace Both Front Brake Rotors 2 15984036 ** SK-00 V8161 0.6 0.1 L Van

* Campaign Administrative Allowance.

** The "Parts Allowance" should be the sum total of the current GMSPO Dealer Net price plus 30% of all parts required for the repair.

Dealers will automatically receive the correct labor and material allowance based on the labor operation performed.

Refer to the Chevrolet Claims Processing Manual for details on Product Campaign Claim Submission.

Dear Chevrolet Truck Owner:

This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act.

REASON FOR THIS RECALL

General Motors has determined that a defect which relates to motor vehicle safety exists in 1988-92 Chevrolet K1500 and K2500 series Full Size Pickups, Blazers and Suburbans, and 1990-92 Chevrolet All- Wheel-Drive Astro vans registered in severe corrosion states.

These vehicles have composite front brake rotors. If severe corrosion were present, the stamped-steel center section of the composite front brake rotor could separate from the cast outer rotor resulting in a total loss of braking capability of the affected wheel. Partial loss of front braking at a time when stopping distance is at a minimum could result in a vehicle crash without prior warning.

WHAT WILL BE DONE

To prevent this condition from occurring, your dealer will replace both front brake rotors with rotors having a corrosion protective coating. This service will be performed for you at no charge.

During brake rotor replacement, it may be determined that due to normal wear your vehicles brake linings require replacement. However, replacement of brake linings is considered a normal maintenance item. Replacement of the brake linings, if necessary, will be performed at your expense.

WHAT YOU SHOULD DO

Please contact your Chevrolet dealer as soon as possible to arrange a service date and so the dealer may order the necessary parts for the repair. Instructions for making this correction have been sent to your dealer and parts are available. The labor time necessary to perform this service correction is approximately 30 minutes. Please ask your dealer if you wish to know how much additional time will be needed to schedule and process your vehicle.

Your Chevrolet dealer is best equipped to obtain parts and provide service to ensure that your vehicle is corrected as promptly as possible. If, however, you take your vehicle to your dealer on the agreed service date, and they do not remedy this condition on that date or within five (5) days, we recommend you contact the Chevrolet Customer Assistance Center by calling 1-800-222-1020.

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.
 
  #6  
Old 04-14-08, 05:30 PM
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Can't find anything that talks about the 96 (or my older 95 for that matter). How could one "measure" let alone detect corrosion at the hat/disc joint?
 
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