Break Fluid Leak

[navdoc101]

I have a VERY slow break fluid leak. I've had 'Tiva a little over a year now & have had to add break fluid twice now. I usually wait 'till its half empty to refill. I have checked the wheel cylinders & the MC & can find no ovious leaks. Any ideas whats goin' on.

[navdoc101]

guess not.

[Movin]

Brake fluid evaporates fairly fast unlike oil, so you are looking for a collection
of dust, not a drip. Pull the dust boots back a little on the bottom to see if
any liquid is there. Make sure the drip slot between the MC and the booster
is open so any leak there won't be forced into the booster.

[georgeb]

If the brake lines are not rusty I would live with it. The light should come on when it needs fluid. When it starts leaking faster you will find it.

[navdoc101]

Yeahits only gone down to half 2X in a year, light came on once, & it was only slightly below half. The booster is very grity below the mc, but dry. I plan on a escort mc switch in the near future. Very unrusty car; is unrusty a word?

[lessersivad]

Yeahits only gone down to half 2X in a year, light came on once, & it was only slightly below half. The booster is very grity below the mc, but dry. I plan on a escort mc switch in the near future. Very unrusty car; is unrusty a word?

I know this will seem rather obvious so forgive me for posting this.

When's the last time the front pads were changed?

The reason I ask is as the pads wear, the caliper pistons push further out of the caliper bore, letting more fluid go from the master cylinder to the calipers.

Being the fluid is only being topped off 2X's in a year leads me to believe that there is no leak, but rather normal friction material use causing the fluid level to drop.

This is only a WAG and simply my 2¢.

BTW, I would consider "unrusty" a word. (Like my opinion means anything.)

[navdoc101]

^ you know that makes a lot of sense! Thanks

[WmWatt]

You could remove the rear brake drums and see if the brake cycinders are the cuprits. The fluid would be inside the drum where you can't see it.

BTW I've found that 1/4" drop in the reservoir is pretty obvious somewhere. After replacing the brake lines I had a place where it would drip from a coupling under pressure and make a spot on the garage floor overnight. Reservoir only down 1/4" over a few weeks. Another time a new claiper was leaking at the copper bushings and there was fluid spraying all over the wheel but very little change in the level in the reservoir. Brake fluid is thin so I guess it spreads out a lot. If the reservoir is down by half I'd expect to see fluid somewhere.

[zoom zoom]

One really prone spot for leaks (on all cars) is right under the driver door where the lines bend back up following the body.. I'd check there too just to be sure, moisture builds up and sits there before it drips off.