How to Adjust the Clutch on a 1997 GMC Sonomaby Mike Aguilar
Problems with your 1997 GMC Sonoma manual transmission are usually clutch-related. If the truck isn't accelerating the way it used to, or you're hearing a grinding sound as soon as you start the truck, you need to change the clutch disc and pressure plate. If pressing the clutch pedal does not fully engage the clutch, either the fluid line is leaking or there is air in the system. Being hydraulic, there is no actual adjustment for the clutch as in a mechanical clutch.
Verify that the fluid level is correct in the clutch master cylinder reservoir. If the level is low, wipe the cover before removing it, and fill the reservoir to the proper level. Replace the cap. Facing the engine compartment, the clutch master is to the right and above the steering column, below the brake master cylinder.
Pump the clutch pedal rapidly a number of times. Inspect the clutch fluid lines from the master to the slave on the transmission. Pay particular attention to the quick-connect joints.
Replace leaking lines by pressing the white sleeve on the connectors on opposite sides and pulling the connector apart. The new line snaps in place.
Place the drain pan under the clutch slave cylinder on the side of the transmission. Have your helper press the clutch pedal as far as it goes at least five times, and hold it down. Turn the bleeder screw valve counterclockwise using a flare nut wrench. Watch for air bubbles. Tighten the bleeder valve, and have the helper repeat this process until no more air bubbles are seen. Refill the reservoir as needed during and after this process.
- This procedure can be performed by a single person using a sealed bottle with a tube in it to the bottom half-filled with clean brake fluid. Attach the tube to the bleeder screw and loosen the screw. Pump the clutch pedal 5 to 10 times and tighten the bleeder screw.
- If the clutch pedal slowly goes to the floor as you hold it, there is a leak somewhere, either in a line or internally or externally on one of the cylinders.
- Only use box end or flare nut wrenches on the bleeder screws. Open-end wrenches can damage the fitting.
Things You'll Need
- Drain pan
- Flare nut wrench set
- Two small screwdrivers
- Small bottle of brake fluid (minimum DOT 3)
- Firmly set the parking brake, and ensure the transmission is in first gear.
- Place blocks in front of and behind one wheel, front or rear.
Mike Aguilar is a freelance writer with over 30 years of professional experience as a mechanic and over 10 years experience in the construction and home-improvement fields. He also attended an electrical apprenticeship for two years in Santa Clara, Calif., becoming a licensed low-voltage technician.