Brakes fail when cold

The patient: 1996 Subaru Legacy wagon with 189,000 miles.

The symptoms: When the weather is cold (<30 F) and the car has been sitting over night or in the parking lot at work all day, the first couple of times I press the brake when backing out of the garage or a parking space, the brakes do not work. I can depress the pedal half way, but really need to wham it to get it down further. After a couple of tries, the brakes begin to behave normally but I still need more pressure to get them to engage. When the car has warmed up a bit, the brakes work normally.



Diagnoses:

My dad suggested the brake fluid may have some water in it, and the problem did seem to improve last spring after I had the fluid changed. Apparently brake fluid takes on water readily so it isn’t good enough to change it from a bottle that was opened a few days before. The bottle must be absolutely fresh. I just had brake work done (caliper in the front, new pads in the back) and do not know if they changed the fluid or, if so, they used a brand new bottle. But the problem is happening at a higher temperature this winter than last winter, as high as 30 F for an afternoon.



Any suggestions would be greatly appreciated. Fortunately, I live in a pretty level place and am a careful driver. But having no brakes, even when I’m only at parking lot speed, is quite scary.



Thanks.

Water (from absorption) is my first suspect. The recent brake work doesn’t mean they changed any brake fluid. Change the brake fluid, again. All of the old brake fluid may not have been removed last time. Use a turkey baster, or hand pump, to draw all the brake fluid from the brake master cylinder. Put fresh fluid in. Open the brake bleeder screws on all the wheels. Press the brake pedal, and refill the reservoir, until clean brake fluid comes out the brake bleeder screws. Tighten the screws. Check reservoir. If the problem persists, the brake calipers are sticking, and need replacing.

First off…Driving a car that you know to have faulty brakes is a crime…DON’T do it.

The last time you had brake work done I’m very certain they did NOT change the fluid. That is something that only is done every 30-40k miles. NOT once a year.

Take your car to a good mechanic and have him diagnose the problem. Sounds like it could be water in the line. But it could be something else too.

I can tell you factually that there was a recall on some '96 & '97 Subaru Legacy and Outback models for those exact symptoms, under the exact same low temperature conditions, and the recall was announced somewhere around '97 or '98, IIRC. Apparently the previous owner ignored the recall notice, which illustrates one of the possible problems involved with buying a used car!

Anyway, there is no time limit on safety-related recalls, so I would strongly suggest that you:

*NOT drive this car.
*Telephone a Subaru dealer in order to verify that your car’s VIN falls within the recalled VINs.
*Bring the car in (by flatbed truck, not a tow truck as a result of the AWD) for the FREE repair that I believe you are entitled to.

[b]Addendum:

I should have mentioned that the recall repair involves the replacement of your brake master cylinder. And, of course, they will fill your hydraulic system with fresh brake fluid at no charge.[/b]

Footnote:
WHY do people ignore recall notices? I have read that a fairly low percentage of cars are actually brought in after recall notices are sent out, and this puzzles me. Free repairs that could save one’s life are offered. Why would someone not avail himself of that??

This problem does not sound like a water-in-brakes problem. Brake fluid will not absorb so much water to the point that the fluids can separate and the water freezes.

I suspect a master cylinder malfunction. As VDC has already said, contact Subaru customer service with your VIN and arrange for servicing under safety recall. Please let us know the results.