brake flush plug keeps coming off....

[NotQuiteFOB]

Very strange problem...

noticed brake fluid low, checked for leaks. Noticed that one of the two brake flush rubber plugs was not on in the driver side rear caliper. Plugged it up, filled it up, drove around. Notice that the plug popped off again. Tried it a few times and it seems like everytime I drive the car, the rubber plug decides to pop off and leak a tiny amount of brake fluid.

Anyone know what's going on? Planning on going to the dealer for a flush next week and maybe have them check it out as well.... getting ready for them to tell me that it's because my car is boosted lol...

[lithium1330]

If you have a leak, you'll want to fix that quick. Brake fluid will eat paint - if only small leak, it may just take the caliper paint. If more, you risk getting that on the wheel and body panel. Take a (IIRC) 10mm wrench to the bleeder screw that's leaking... loosen it up just a little bit then tighten it up again. Wash the bleeder screw/plug/caliper with water and a rag (to make sure you wish off any residual brake fluid). Dry everything up with a paper towel (screw, rubber plug, etc.) - you don't have to cap the rubber plug yet. Turn on the car and stand on the brake and see if the pedal gives you that "sinking" feeling. It should be relative solid about 1/2 way down. Count to 10, then go do a visual on the bleeder screw (around the base and inside the bleeder screw) to make sure everything is still dry. G luck.

[NotQuiteFOB]

If you have a leak, you'll want to fix that quick. Brake fluid will eat paint - if only small leak, it may just take the caliper paint. If more, you risk getting that on the wheel and body panel. Take a (IIRC) 10mm wrench to the bleeder screw that's leaking... loosen it up just a little bit then tighten it up again. Wash the bleeder screw/plug/caliper with water and a rag (to make sure you wish off any residual brake fluid). Dry everything up with a paper towel (screw, rubber plug, etc.) - you don't have to cap the rubber plug yet. Turn on the car and stand on the brake and see if the pedal gives you that "sinking" feeling. It should be relative solid about 1/2 way down. Count to 10, then go do a visual on the bleeder screw (around the base and inside the bleeder screw) to make sure everything is still dry. G luck.

Thanks. I was able to check it out this morning and it was exactly as suspected, loose bleeder screw. Interestingly, the brakes were never flushed since purchasing the car over a year ago, and haven't had any problems until now. Must not have been properly torqued by whoever bled the brakes before me.

side note, the screw is 11mm not 10mm. '06 cayman s, with red calipers.