CloudLS9

In the 1.5 months I've had my ZR1, the clutch pedal has stuck in a few times, but only after a brief 3rd gear pull on the highway each time. It doesn't do this every time, but I think it's happened 3 times total. Each time, I didn't shift in to 4th, rather I let off the gas and held the clutch in for a while to coast back to normal speed. After lifting my foot from the clutch, one time the clutch stayed down for a moment before returning on it's own. The next two occasions when this occurred, I popped it back up with my toe not waiting to see if it would return on its own. Driving around town the clutch feels great with light action and no issues shifting between any of the gears.

I've read up on this a bit and found a few different reported causes for this: Dirty or low clutch fluid, high temps corrupting fluid, master cylinder issues, slave cylinder issues and issues with clutch pedal spring.

The clutch fluid is full and was clean when I checked a few weeks ago and temps have been relatively cool this time of year. I don't know what brand of clutch fluid is in the car. I was thinking about picking up some Castrol SRF based on recommendations in other threads. Do I need to fully bleed the system, or can I use the ranger method and mix with whatever is in there?

Any other signs to look for to differentiate between potential causes? I doubt any of these parts are covered under the extended warranty, but I would rather fix any potentially suspect part before it breaks and leaves me stranded.

Also, in case it's relevant, the car only has 20k miles and I don't expect the clutch has ever been abused. The 1st owner was 76. I'm the 2nd owner and I've been driving manual cars for 20 years. I have never dumped the clutch or done any hard shifts and wouldn't expect the prior owner did either based on his age / maturity.

Thanks,

-Ion

jft69z

There's a recall for that. Your car should be covered. Have your local dealer run your VIN and it should show up as being eligible for special coverage 14717.

https://www.corvetteforum.com/forums...post1590616079

https://www.corvetteforum.com/forums...seen-this.html

CloudLS9

Thanks again. I registered through the GM owner center as recommended in one of your links. I can see 1417 bulletin under the warranty section as extended coverage through 2021.. this appears to be more of a warranty extension rather then a recall as the VIS report doesn't show any open recalls or record of this service ever being performed on this vin. The letter some received said don't bring your car in unless the clutch pedal fails to return.

Now the question is do I have to wait until it fails completely and never returns and tow it to shop, or must I let the shop do repeated 3rd gear pulls on the freeway until they can replicate the issue, or will they just take me on my word and replace it before I get stuck somewhere.

Regardless, thanks for the link and saved $.

jft69z

Just tell them your clutch sticks to the floor and it should be no problem. It's a safety issue, if the service writer gives you any problem either ask for the service manager or go to a better dealer.

ZR1Cat

OP, ditto this wise advice. Don't wait; get it serviced pronto. There is no need to tolerate this problem that could even leave you stranded. Fortunately GM is aware of this faulty condition and has a better replacement part.

1Sikstik

I had my master cylinder replaced on my 2013 ZR by the dealer at no charge. I dont like that the whole assembly is black and I cant see when the fluid gets dirty, but it did fix the problem.

jft69z

I kept the clear reservoir from my original M/C and put it on the new assembly. Turned the old one back in with the black reservoir for the warranty return.

CloudLS9

How often should one do the ranger method with the new unit? Does the new version do a better job keeping the fluid clean?

Also, should I bring my own Castrol SRF or just roll with the DOT4 the dealer has?

jft69z

After replacing mine, it stays pretty clean, but I filled it with Castrol SRF. I was doing a brake system flush and decided to swap out the M/C at the time since it was up in the air anyhow.

If you just have the dealer do it and keep the black reservoir, it will come prefilled with brake fluid. It's doubtful they'll actual bleed the entire system with the bleeder screw at the top of the bellhousing. They'll just pop it in and go. To bleed the system the exhaust manifold, torque tube heat shield, etc. needs to come off. Lot of work. I did it all because it was MY car.

Maybe ask them if they will swap the reservoir for you so you can see the condition of the fluid, can't hurt to ask. I had them do that to a customer's car when the clutch pedal stuck to the floor on me while taking it for a test drive after doing other work. Drove it right to my dealer where they ordered it on the spot. The tech swapped the reservoir for us at my suggestion, no problem. Everyone happy.