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I have a 2002 GMC 6500 vin 1GDJ7H1E92J900204..I need some

Customer Question

i have a 2002 GMC 6500 vin 1GDJ7H1E92J900204..I need some info on how the parking brake works,,, basically the brake is working backwards,, you push the button in (to release), the hydraulic motor comes on pushing the cable forward, from what i read this should relase but instead it locks,,, tried every configuration of cable and linkage I can think of and nothing works,,, but I'm not sure the electrical or the hydraulic or the mechanical is what is the problem,,, I NEED HELP on where to start!!!!!!
Submitted: 25 days ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 25 days ago.

Hi my name is***** will be glad to try to help. Sounds like something is reversed electronically or the park brake switch has a problem. Has there been any changes done to the wiring? Check the harness for damage, modifications, or shorts from the switch to the actuator. Let me know

Customer: replied 25 days ago.
no there hasn't,, when you push the button to releaase the brake the daytime running lights comes on like that part is working correctly, from what I've read the hydraulic pump should come on and build pressure to override the spring in the actuator to release the brakes,, it does all that but instead of releasing it locks,,, if you turn the key off or pull the brake knob the sloenoid valve dumps and the brakes release when they should lock
Expert:  Daniel Wilson replied 25 days ago.

Thanks for the update. The brake should be locked anytime there is no pressure there. If the hydraulic actuator is putting pressure to release the brake but it wont release it meand either the pump is bad, there is a leak externally or internally such as a failed actuator. Try adapting a porta power and guage to see if it will hold pressure. you only need a low pressure to test such as around 250- 300 psi to see if the seals hold. Let me know

Customer: replied 25 days ago.
with you so far,,, have good pressure at the actuator, only it is locking the brake not releasing,, pulled the brake apart at the drum,, when the pressure is supplied the actuator pushes the cable forward, pulling down on actuator arm which is locking the brake not releasing, have tried every possible way of adjusting linkage and cannot get it to work properly
Expert:  Daniel Wilson replied 25 days ago.

I recommend pulling the drum off the parking brake ans see if the linings and drum is excessively worn or something damaged

Customer: replied 25 days ago.
i have the drum off watching the shoes,, it works smoothly,,, only in reverse,, pulled some codes off control module 03,04,09,01,13 and 08....
Expert:  Daniel Wilson replied 25 days ago.

00005: Product Safety - Auto-Apply Park Brake Performance - (Oct 18, 2000)

Subject: 00005 -- Auto-Apply Park Brake Performance

Models: 1994-1999 GMC C-Series Medium Duty Trucks
1997-1998 GMC T-Series Medium Duty Trucks

--------------------------------------------------------------------------------
Condition
Some 1994-1999 GMC C-Series and 1997-1998 T-Series Medium Duty Trucks equipped with the auto-apply park brake (RPO J71) and sold for use in Canada may exhibit certain malfunctions that generally may cause the park brake to operate in the as-designed failure mode. These malfunction conditions are as follows:
• An interruption of electrical power to the hydraulic pump due to a solenoid failure, or
• Water contamination of the DEXRON®III transmission fluid in the reservoir due to inadequate sealing.
The first condition can cause an unintended park brake apply at speed. By design, the auto-apply park brake will apply as a fail-safe mode if any power interruption or fluid pressure loss occurs. If this occurred, the Park Brake warning lamp would illuminate, and there would be a noticeable deceleration of the vehicle. There would be no loss of vehicle control and the driver could bring the vehicle to a safe stop at the side of the road. The second condition could cause a slow apply or release of the park brake. The general system requirement for apply or release is 3 to 5 seconds. Longer times (10 seconds) could occur if the reservoir fluid temperature is above 55°C (130°F) or below -18°C (0°F). There is a warning in the Owner's Manual that the driver should not exit the vehicle until the park brake has fully set and the red warning light indicating this has illuminated. Both conditions could cause a failure to release the park brake when the vehicle is parked. Failure to release is a warning feature to prevent damage and should be an indication to the operator to have the vehicle system checked for abnormalities.
As a result of these conditions and their consequences described above, Transport Canada has informed General Motors of Canada Limited that it believes a safety defect exists in these vehicles. General Motors of Canada Limited has agreed to rectify the conditions by conducting a safety campaign.
To help prevent the possibility of these conditions occurring, dealers are to seal the parking brake pump and the reservoir. Some C-Series vehicles are to also have a more durable solenoid installed (T-Series and some C-Series vehicles are already equipped with this solenoid). Included with their notification, owners will receive an updated maintenance schedule to insert into their Owner's Manual (see the copy at the end of this bulletin).
Vehicles Involved
Involved are certain 1994-1999 GMC C-Series and 1997-1998 T-Series Medium Duty Trucks equipped with auto-apply park brakes (J71) and sold for use in Canada and built within the following VIN breakpoints:
Year
Division
Model
Plant
From
Through
1994
GMC
C
Janesville
RJ502453
RJ524067
1995
GMC
C
Janesville
SJ500065
SJ526782
1996
GMC
C
Janesville
TJ500058
TJ517676
1997
GMC
C
Janesville
VJ500135
VJ514306
1998
GMC
C
Janesville
WJ500495
WJ512237
1999
GMC
C
Janesville
XJ506117
XJ519910
1997
GMC
T
Janesville
VJ506117
VJ510922
1998
GMC
T
Janesville
WJ500774
WJ503258
Important: Dealers should confirm vehicle eligibility through GM Access or VIN listing prior to beginning campaign repairs. (Not all vehicles within the above breakpoints may be involved.) Only affected VINs will be paid.

Involved vehicles have been identified by Vehicle Identification Number. Computer listings containing the complete Vehicle Identification Number, customer name and address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name and address data furnished will enable dealers to follow-up with customers involved in this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.
These dealer listings may contain customer names and addresses obtained from the Inter-Provincial Records. The use of such motor vehicle registration data for any other purpose is a violation of provincial laws. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign.
Parts Information
Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your Involved Vehicles Listing prior to ordering requirements.
Part Number
Description
Qty/ Vehicle
12388081
Solenoid Coil
1 (C-Series Only)
00993033
Optikleen Glass Cleaner
500 ml
12346286
RTV Silicone Rubber Sealant
1*
15156687
O-Ring Seal
1 (If Required)
10952624
DEXRON®III Trans Fluid
1 L
15753013
Maintenance Label
1
* -- One tube will service two vehicles.
Customer Notification
All customers of record at the time of campaign release are shown on the attached computer listing and have been notified by first class mail from General Motors (see copy of customer letter included with this bulletin).
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 customers take possession of these vehicles.
Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward.
Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer 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.
Service Procedure
•Remove the three bolts and the compartment box top.
•Remove the parking brake reservoir from the pump assembly.
•Drain the fluid from the reservoir.
•Clean the reservoir and the pump mating surfaces using residue-free Optikleen Glass Cleaner or the equivalent. Allow to dry completely.
•Apply a 1.6 mm (1/16 in) to 2.4 mm (3/32 in) bead of RTV Silicone Rubber Sealant, or the equivalent, around the diameter of the reservoir where the O-ring is positioned when installed.
Important: Allow the sealer to cure approximately 20 minutes. If the sealer is allowed to cure too long, it may not seal properly.
•Using a protected finger, smooth the sealant uniformly around the diameter of the reservoir.
•While the sealant is curing, loosen the metal pipe at the elbow in the pump inlet and drain the fluid from the pipe. The pipe is routed between the bottom of the solenoid and the pump inlet.
•Reconnect the pipe.
Tighten
Tighten the pipe nut to 16 N·m (12 lb ft).
•Loosen the metal pipe at the actuator inlet and at the tee connector.
•Rotate the pipe and drain it of all fluid. The pipe is routed between the solenoid and the actuator.
•Reconnect the pipe.
Tighten
Tighten the pipe nut to 16 N·m (12 lb ft).
•Remove the O-ring located between the pump and the reservoir. Wash the O-ring in hot, soapy water and dry it.
•Inspect the O-ring. Replace the O-ring if it is damaged.
Important: The locating pin on the reservoir should be in the hole of the adapter ear when properly oriented. The reservoir fill neck orientation should be inboard, toward the frame rail and toward the centre of the component box.
•Reinstall the O-ring on the pump assembly.
•Install the reservoir to the pump assembly.
•Install the reservoir attaching cap screws.
Tighten
Tighten the screws to 6 N·m (50 lb in).
•If the vehicle is a 1994, 1995 C-Series or is a 1996 C-Series with VIN 1GDG6H1M0TJ514115, 1GDJ6H2J6TJ514132 or 1GDl7H1MTJ514026, proceed to Step 17 as these vehicles do not have the durable solenoid installed.
For all other vehicles, proceed to Step 25 as those vehicles have the durable solenoid.
•Disconnect the negative battery cable.
•Disconnect the parking brake solenoid coil electrical connector.
•Remove the nut and the metal label that is retaining the solenoid coil to the parking brake solenoid valve assembly.
•Remove the solenoid from the valve assembly and discard it.
•Install the new 12-volt solenoid coil to the valve assembly.
•Install the metal label and the coil retaining nut.
Tighten
Tighten the nut to 8 N·m (6 lb ft).
•Connect the parking brake solenoid coil electrical connector.
•Connect the negative battery cable.
•Fill the reservoir between the minimum (MIN) and the maximum (MAX) lines with DEXRON®III transmission fluid.
•Apply and release the parking brake three or four times to ensure proper operation.
•Inspect for leaks and correct any leaks as required.
•Recheck the fluid level in the reservoir and add fluid if necessary.
•Install the component box top.

•Using a clean, dry cloth, wipe any dirt, oil, etc., from the upper right hand corner of the component box top. Install the maintenance label.
•Install the Campaign Identification Label.
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 by the customer for periodic servicing. Additional Campaign Identification Labels can be obtained from DGN by calling 1-***-***-**** (Monday-Friday, 8:00 am to 5:00 pm Eastern Standard Time). Ask for Item Number GMP 91 when ordering.
Apply the "Campaign Identification Label" only on a clean, dry surface.
Claim Information
Submit a Product Campaign Claim with the information indicated below.
Repair Performed
Part Count
Part No.
Parts Allow
CC-FC
Labour Op
Labor Hours*
Net Item
Seal Parking Brake Pump & Reservoir; Install Maintenance Label
0 or 1
--
**
MA-96
V0461
0.5 hr
***
Seal Parking Brake Pump & Reservoir and Install New Solenoid Coil & Maintenance Label
1 or 2
--
**
MA-96
V0462
0.7 hr
***
* -- For Campaign Administrative Allowance, add 0.1 hours to the "Labour Hours".
** -- The "Parts Allowance" should be the sum total of the current GMSPO Dealer Net price plus 40% for parts needed to complete the repair.
*** -- The amount identified in the "Net Item" column should represent the sum total of the Current GMSPO Dealer Net Price plus 40% for the actual amount of cleaner, sealant, and transmission fluid needed to perform the required repairs, not to exceed $20.00

Refer to the General Motors Claims Processing Manual for details on Product Campaign Claim Submission
Owner Manual Insert

February, 2000
Dear General Motors Customer:
Some 1994-1999 GMC C-Series and 1997-1998 T-Series Medium Duty Trucks equipped with the auto-apply park brake and sold for use in Canada may exhibit certain malfunctions that generally may cause the park brake to operate in the as-designed failure mode. These malfunction conditions are as follows:
• An interruption of electrical power to the hydraulic pump due to a solenoid failure, or
• Water contamination of the DEXRON®III transmission fluid in the reservoir due to inadequate sealing.
The first condition can cause an unintended park brake apply at speed. By design, the auto-apply park brake will apply as a fail-safe mode if any power interruption or fluid pressure loss occurs. If this occurred, the Park Brake warning lamp would illuminate, and there would be a noticeable deceleration of the vehicle. There would be no loss of vehicle control and the driver could bring the vehicle to a safe stop at the side of the road. The second condition could cause a slow apply or release of the park brake. The general system requirement for apply or release is 3 to 5 seconds. Longer times (10 seconds) could occur if the reservoir fluid temperature is above 55°C (130°F) or below -18°C (0°F). There is a warning in the Owner's Manual that the driver should not exit the vehicle until the park brake has fully set and the red warning light indicating this has illuminated. Both conditions could cause a failure to release the park brake when the vehicle is parked. Failure to release is a warning feature to prevent damage and should be an indication to the operator to have the vehicle system checked for abnormalities.
As a result of these conditions and their consequences described above, Transport Canada has informed General Motors of Canada Limited that it believes a safety defect exists in these vehicles. General Motors of Canada Limited has agreed to rectify the conditions by conducting a safety campaign.
To help prevent the possibility of these conditions occurring, dealers are to seal the parking brake pump and the reservoir. Some C-Series vehicles are to also have a more durable solenoid installed (T-Series and some C-Series vehicles are already equipped with this solenoid). In addition, included with this letter is an updated maintenance schedule for the solenoid. Please place this insert in the Section titled "Maintenance Schedule" of your Owner's Manual for future reference.
Please contact your GM dealer as soon as possible for details regarding their availability. If parts are not in stock, they can be ordered before scheduling your service date.
This letter identifies your vehicle. Presentation of this letter to your dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.
We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.
Customer Support Department
General Motors of Canada Limited
Enclosure
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.

Customer: replied 25 days ago.
I don't know if I'm explaining myself correctly... directly from Chevrolet C series service manualCircuit Description
in order to release the parking brake, the pump motor must supply fluid pressure to the actuator. when this pressure overcomes the spring tension inside the actuator, the actuator piston moves, releasing the parking brakethe motor supplies fluid pressure, it overcomes the spring tension inside the actuator,,, the piston moves,,, but that sets the brake... the more I dig the more it seems to be mechanical,, had a Chevy mechanic stop by and he's just as baffled as me... tried changing adjusters and position of linkage every way we can imagine and nothing changes
Expert:  Daniel Wilson replied 24 days ago.

Can you take a picture or the brake assembly with and without the drum for me? Also I would like to see the internals.

Customer: replied 23 days ago.
I'll have the pics for you Monday,,, got stuck on another project
Expert:  Daniel Wilson replied 21 days ago.

Keep me posted.... I may be out on a road call Monday and Tues only leaving the evenings but its still up in the air...

Customer: replied 19 days ago.
here are the pictures.
Customer: replied 19 days ago.
IMG_20161121_11202025911.JPG picture is the brakes released but the are locking
Customer: replied 18 days ago.
was wondering if youd had a chance to look at pics yet
Customer: replied 13 days ago.
just checking to see if you could figure anything out on those pics
Expert:  Daniel Wilson replied 12 days ago.

Hi Sorry for the delay. I have been dealing with some medical emergencies. With the yokes disconnected that lever should spread to apply the brake whether moved up or down correct? So this brake is disengaged at all times and then engages when pushing the button to release? It sounds like the switch is plumbed/ wired backwards

Customer: replied 11 days ago.
sorry you were sick... i really dont think it is an electrical problem...with key off spring takes over, which should be locking the brake,, instead it is releasing ....none the less I pulled the linkage apart pressed the center out, turned it where it works correctly and welded it up.... working!!! the only problem I have now is, somehow in the process the "service parking brake" came on,,, pulled some codes off module 03,04,09, 13 and 08
Expert:  Daniel Wilson replied 11 days ago.

Thanks for the update. do you have the code definitions? I know I had the list but I would have to do some digging to find it... Might be on one of my other laptops. Let me know

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