Re: Brake reservoir leakage

Posted by HH56 On 2018/7/28 11:55:25

Am assuming you are talking power brakes?? If so more details on the hose in question please.

There are two metal tubes that go into a Y shaped brass fitting at the end of the master. A single rubber hose enters a fitting at the side of the booster section near the car floor to provide vacuum. A square plate is at the end of the booster section where it mounts to the floor and well away from any hydraulic fluid. If that plate or the rubber vacuum nose next to it is where you see fluid there is a serious seal failure between the hydraulic and vacuum sections and vacuum is most likely sucking the missing fluid out of the reservoir. It needs to be corrected immediately because you don't know when the seal will totally fail and all the fluid will disappear.

If you have the somewhat rare optional remote fill kit with a glass jar on the firewall and that is the reservoir you are concerned about then there is a fluid fill hose connected with that item at the master. If that is where there is a leak, it is not as serious an issue and fluid is running out a damaged hose or poor seal at the cap or lid to the master cylinder.

Addendum: There is a square plate which forms the top of the reservoir and is screwed to the master casting. If that is the plate in question which is wet I think the fiber gasket around the fill plug may have deteriorated or broken allowing fluid to leak. Possibly the gasket between plate and casting is damaged allowing fluid to leak out and be blown on top of the plate. That would be very evident with the remote fill kit providing more fluid but not so much if there is no other source of fluid other than what is in the master reservoir. It would not account for an inch loss in the master reservoir but would in a remote fill reservoir.