# Brake system leak...looking for part name **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** neon, dodge\ **Created:** [November 21, 2016, 11:37pm UTC](https://community.cartalk.com/t/brake-system-leak-looking-for-part-name/96604 "2016-11-21T23:37:12Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![meanjoe75fan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/meanjoe75fan/32/552_2.png) [@meanjoe75fan](https://community.cartalk.com/u/meanjoe75fan)\ **Post date:** [November 21, 2016, 11:37pm UTC](https://community.cartalk.com/t/brake-system-leak-looking-for-part-name/96604/1 "2016-11-21T23:37:12Z")
2002 Neon, 140K mi. Step-son complained of “soft pedal,” determined fluid had been run low in one of the two circuits. I replaced both leaking rear wheel cylinders on this car. At the time, couldn’t find any other leaks, and I called it a day. Today, he came back, complaining of dropping fluid level. Bled system and looked for leaks. As it turned out, fluid was leaking _near_ the master. On this design, there are four brake lines from the MC. On two of the four, there is some form of aluminum nut, with a rubber gasket “sandwiched” in the middle. (This screws into the MC, and the line screws into this nut.) There was a second leak from one of the two rubber gaskets. So…the MC is (potentially) OK, and auto parts diagrams don’t show these parts. What is this part, and how do I order it? I don’t know what it is, exactly…maybe some weird proportioning valve setup? (Perhaps in 24 hr or so I can get a photo of it.) ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [November 21, 2016, 11:49pm UTC](https://community.cartalk.com/t/brake-system-leak-looking-for-part-name/96604/2 "2016-11-21T23:49:04Z")
Try proportioning valve o rings, Look like this? ![](https://global.discourse-cdn.com/cartalk/original/2X/0/056825c83d1cdb1a111a8185a389485bed876135.gif) ---
**Author:** ![meanjoe75fan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/meanjoe75fan/32/552_2.png) [@meanjoe75fan](https://community.cartalk.com/u/meanjoe75fan)\ **Post date:** [November 21, 2016, 11:54pm UTC](https://community.cartalk.com/t/brake-system-leak-looking-for-part-name/96604/3 "2016-11-21T23:54:21Z")
Yeah, that looks like it, but that sure wasn’t what AAP showed! Looks like this: ![](https://global.discourse-cdn.com/cartalk/original/2X/1/1e6ec3d455b7c76a7a2cdb3e777775d4105fcb2f.jpg) It’s squirting out of the larger o-ring. Guess it needs new rubber parts! ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [November 22, 2016, 1:16pm UTC](https://community.cartalk.com/t/brake-system-leak-looking-for-part-name/96604/4 "2016-11-22T13:16:31Z")
Be sure and use the proper O-ring, NOT just any Buna-N or Nitrile O-ring from the hardware store. Brake fluid will destroy anything but EPDM O-rings. Soak them in a little brake fluid overnight before installing. Buna-N will swell, EPDM will not.