I put new brake rotors and pads on the front of my 2009 HHR LT today. In the process the master cylinder cover fell into the engine bay. I've looked but can't find it so I put a double layer of heavy plastic sheeting over the master cylinder opening and secured it with rubber bands. Will this suffice until I can find a new cover?

 

You might put a pin hole in the sheet. the cap is only there to keep it from sloshing out and keep dirt out. Fluid will be going in and out so you need some venting.

 

Look carefully down below the master cylinder, it might have ended up in the steering rack and swaybar area of the engine cradle or it might have landed on the transmission.


On the area by the swaybar and steering rack

Down there by the red arrow

 

When ya find a proper cap, not a bad idea to suction out the existing Dot 3 brake fluid from the master & add fresh. This fluid is hygroscopic, and it absorbs all moisture from the brake fluid.

 

I was hoping to keep moisture out of the master cylinder with the plastic. Won't a pin hole let moisture in?

I will look again to see if I can find it. The pictures help.

I didn't think of replacing the brake fluid once I get a cap so I will do that. Good idea.