TSB PIT3665G — Chevrolet and GMC Service bulletin

PIT3665G is a service bulletin on file with NHTSA for 2 Chevrolet and GMC models, 1998–1999 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.

What the bulletin says. 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.

NHTSA's own summary of the document, quoted from the public manufacturer-communications file.

1Document filed
2Vehicles named
2Model years

Vehicles and model years PIT3665G names

VehicleModel years
Chevrolet Silverado 1500 1998, 1999
GMC Sierra 1500 1998

Every document filed under PIT3665G

Document IDFiledType
PIT3665G May 13, 2019 Service bulletin

What PIT3665G covers

Brakes & stability — the component vocabulary NHTSA files this communication under.

← All Chevrolet Silverado 1500 TSB years TSB lookup by model

Questions buyers ask

What is TSB PIT3665G?

PIT3665G is a service bulletin filed with NHTSA by Chevrolet and GMC, covering 2 Chevrolet and GMC models across the 1998–1999 model years. NHTSA's summary reads: 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.

Which vehicles does PIT3665G cover?

NHTSA's file names Chevrolet Silverado 1500 (1998–1999); GMC Sierra 1500 (1998). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.

Is TSB PIT3665G a recall, and is the repair free?

No. PIT3665G is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.

How do I get the full text of PIT3665G?

Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under PIT3665G, its date, and NHTSA's own summary from the public file.

Data updated 2026-08-20 from NHTSA's public records

Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under PIT3665G. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.