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Service bulletin PIT-3665-D

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10078876
Published by NHTSA2016-08-24
Manufacturer's numberPIT-3665-D
Manufacturer's date2016-05-11
NHTSA componentSERVICE BRAKES, HYDRAULIC:PEDALS AND LINKAGES

NHTSA's summary

THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN THAT THE HYDRO-BOOST IS NOT SERVICEABLE AND WILL NEED TO BE REPLACED IF THE BRAKE PEDAL MOVES OR APPLIES ON ITS OWN AT A FULL TURN.

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Brakes

Vehicles listed
CADILLAC ESCALADE2001, 2002, 2003, 2004, 2005
CADILLAC ESCALADE ESV2003, 2004, 2005 (the catalog's model; the bulletin names a series or trim of it)
CADILLAC ESCALADE EXT 15002002, 2003, 2004, 2005 (the catalog's model; the bulletin names a series or trim of it)
CHEVROLET ASTRO1998 to 2005
CHEVROLET AVALANCHE 15002002, 2003, 2004 (the catalog's model; the bulletin names a series or trim of it)
CHEVROLET EXPRESS1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
CHEVROLET SILVERADO 15001998
CHEVROLET SILVERADO 15001999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it)
CHEVROLET SUBURBAN2001, 2002, 2003, 2004, 2005
CHEVROLET TAHOE2001, 2002, 2003, 2004, 2005
GMC DENALI2001 to 2003
GMC SAFARI1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
GMC SAFARI (GMC)1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 (the catalog's model; the bulletin names a series or trim of it)
GMC SAVANA1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
GMC SIERRA 15001998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it)
GMC YUKON2001, 2002, 2003, 2004
GMC YUKON DENALI2001, 2002, 2003, 2004 (the catalog's model; the bulletin names a series or trim of it)
HUMMER H22002
HUMMER H22003, 2004, 2005, 2006, 2007

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
24V7020002024-09-19. SERVICE BRAKES, HYDRAULIC:POWER ASSIST:HYDRAULIC:HOSES, LINES/PIPING, AND FITTINGS
20195332019-10-24. Brakes
19V7610002019-10-24. SERVICE BRAKES; SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:WHEEL SPEED SENSOR/TONE RING; ELECTRONIC STABILITY CONTROL (ESC)
19V6450002019-09-06. SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM
20193242019-06-28. Brakes
20184642018-08-31. Brakes
18V5780002018-08-30. SERVICE BRAKES, HYDRAULIC:PEDALS AND LINKAGES
16V0690002016-02-05. SERVICE BRAKES, HYDRAULIC:PEDALS AND LINKAGES
20160532016-02-04. Brakes
20153522015-08-05. Brakes

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
25-NA-0652025-04-24. Service bulletin. This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
21-NA-0432025-02-12. Service bulletin. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
21-NA-0432024-12-10. Service bulletin. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
PIT5282G2024-09-13. Service bulletin. This Preliminary Information communication provides information to the technician that a customer may request the factory Integrated Trailer Brake Control be bypassed and their aftermarket trailer brake controller be installed instead. Technician will need to gain access to the body harness. Install trailer brake controller harness General Motors part number 23184088 into Middle Bus Electrical Center (X61A).
PIT5509L2024-09-11. Service bulletin. This Preliminary Information communication provides information to the technician on how to diagnose and repair vehicle that may have a "Check Trailer Wiring" or "Service Trailer Brake System” message on the Driver Information Center when a trailer is connected to the vehicle. Diagnostic Trouble Code C1114 set in the Chassis Control Module. Chassis Control Module has to determine the type of trailer brake system that is being used. The Chassis Control Module can be sensitive to a variety of trailer wiring issues. The technician will need to make a trailer tester using Electric Trailer Brake Magnets and 7-way trailer connector to determine if it is a vehicle or trailer issue. If the concern is not duplicated with the tester installed, the vehicle is operating correctly and the focus should be on the trailer wiring or 7 way connector.
PIT62122024-09-11. Service bulletin. This Preliminary information communicates an issue with the Hydrastar Electric Over Hydraulic trailer brake system causing a voltage spike into the trucks electrical system which is causing DTC C1114 to set.
PIP5596A2024-04-15. Service bulletin. This Preliminary information communicates that when removing the fuel line jumper hose care should be taken to be sure the line is reinstalled correctly to avoid a no/low fuel pressure situation.
PIT5479F2024-03-18. Service bulletin. This Preliminary Information communication provides information to the technician about fluid leaking from the brake caliper piston area found during a service of the vehicle. The substance is actually excess assembly grease from the caliper boot and piston installation. This grease can be cleaned off and the rest of the service completed.
228602024-01-08. Service bulletin. Harness Trapped Under MBEC
PIT5120A2023-12-26. Service bulletin. Stabilitrak/Traction Control OFF With Red Brake Warning Lamp