[Kid JDM]

2016 1LT V6 M6 RS. Zero modifications, ~80,000mi

In March of 2020 I woke up to find my clutch pedal stuck to the floor. Towed to the dealership who replaced the clutch, pressure plate, flywheel, and master cylinder. Same issue happened again in July 2020. Towed back to the dealer who replaced the master cylinder again.

December 2020, same issue again. Towed back to the dealership who began ignoring my voicemails. After two weeks I go to them in person where they admit that:
1) They have no idea what is going on and need to contact a GM factory tech
2) The part is on indefinite backorder

And of course there's no loaners and the sizeable check I've already cut to them for the previous work doesn't get me any higher on the waiting list.

Anyone ever encountered anything similar?

[STYLO LT1]

Well, if they’re giving up maybe it’s time to lawyer up! They attempted the repair because they are “supposedly” trained to repair our cars to your satisfaction. If they can’t fix it, then they need to give you your money back.

[ctrlz]

This is the closest troubleshooting guide I could find in the repair manual. It doesn't say, "clutch drops to floor," but rather, "clutch no load," and indicates the clutch will not disengage in this circumstance. Does that sound like what's happening?

So, the one thing your post does not mention is the clutch concentric actuator cylinder.

DIAGNOSTIC INFORMATION AND PROCEDURES > CLUTCH - NO LOAD

DEFINITION: Regardless of ambient temperature and vehicle on/off operational status, the clutch pedal effort is zero/light in both up-stroke and down-stroke and the clutch will not disengage.
Review Symptoms - Clutch and perform the necessary inspections.

Cause: Internal damage to the clutch master cylinder and the hydraulic system

Action:

1. Inspect for fluid leaks.

2. Replace the clutch hydraulic system. Refer to Clutch Master Cylinder Replacement , and Hydraulic Clutch Hose/Pipe Replacement (M13) Hydraulic Clutch Hose/Pipe Replacement (MM6) .

3. Replace the clutch master cylinder and the clutch actuator cylinder (CSC). Refer to Clutch Master Cylinder Replacement , and Clutch Concentric Actuator Cylinder Replacement .

4. Re-bleed the clutch hydraulic system. Refer to Hydraulic Clutch System Bleeding .


Description of clutch hydraulics:
DESCRIPTION AND OPERATION > CLUTCH SYSTEM DESCRIPTION AND
OPERATION > HYDRAULIC CLUTCH DESCRIPTION
The clutch hydraulic system consists of a master cylinder and an actuator cylinder. When pressure is
applied to the clutch pedal, pedal depressed, the pushrod contacts the plunger and pushes it down the
bore of the master cylinder. In the first 0.8 mm (0.031 in) of movement, the compensation port seal
closes the port to the fluid reservoir tank, and as the plunger continues to move down the bore of the
cylinder, the fluid is forced through the outlet line to the actuator cylinder mounted to the driveline support
assembly. As fluid is pushed down the pipe from the master cylinder, this in turn forces the piston in the
actuator cylinder outward. As the actuator cylinder piston moves forward, it forces the release bearing to
disengage the clutch pressure plate from the clutch disc. On the return stroke, pedal released, the
plunger moves back as a result of the return pressure of the clutch. Fluid returns to the master cylinder
and the final movement of the plunger opens the port to the fluid reservoir, allowing an unrestricted flow
of fluid between system and reservoir. Some systems may have a clutch pedal over-center spring. The
clutch pedal over-center spring provides load at the top of stroke and reduces clutch effort at the bottom
of stroke. This reduces driver fatigue during stop and go traffic.

[Kid JDM]

I appreciate the replies. Ultimately it was a pinhole leak in the clutch hose assembly (GM part # 24285373 in case anyone else has the same issue)

[Rock-It Man]

Originally Posted by Kid JDM

I appreciate the replies. Ultimately it was a pinhole leak in the clutch hose assembly (GM part # 24285373 in case anyone else has the same issue)

It's amazing that after replacing the master cylinder twice, the mechanic couldn't figure out where else to look for so long.

[ctrlz]

Originally Posted by Kid JDM

Ultimately it was a pinhole leak in the clutch hose assembly (GM part # 24285373 in case anyone else has the same issue)

Fluid drips under the car? I would think there would be some evidence.
Also, fluid on the hose itself??? Weird that this could be missed (TWICE!).

[SSgtSS1LE]

The clutch hose/pipe is routed under the carpet and exits the car through the top of the transmission tunnel. So, the leak would not be visible if it leaked inside the car. Pull back the carpet and check for paint damage.

2017 - Camaro Service Manual
Brake Fluid Effects on Paint and Electrical Components Caution
Caution: Avoid spilling brake fluid onto painted surfaces, electrical connections, wiring, or cables. Brake fluid will damage painted surfaces and cause corrosion to electrical components. If any brake fluid comes in contact with painted surfaces, immediately flush the area with water. If any brake fluid comes in contact with electrical connections, wiring, or cables, use a clean shop cloth to wipe away the fluid.

[ctrlz]

Originally Posted by SSgtSS1LE

Pull back the carpet and check for paint damage.

Yowza! And make sure they cleaned up the leaked fluid!