What's up fellas, I am losing brake fluid just about on a monthly basis right now. Here is the story:

I drive down interstate 75 and the brake light comes on, I immediately check the fluid when I get home, and it is low enough to trip the sensor. I refill it, push the diaphragm back up in the cap, and be on my way. This was about two months ago. I have had to refill it twice now, with the second being today. I have checked nearly everything I can think of, without having to do anything that would let air in the system. All four wheels are fine, all rubber brake lines, calipers, and the hard lines I could see are fine. I have steady, firm brake pressure all the time, but yet I am still losing fluid. It can't be the master, cause if it was the pedal would go all the way down to the floor at a stoplight, etc., and it can't be the booster, cause I wouldn't be able to push the brake pedal at all. It's just weird, cause my brakes are nearly perfect, yet it still seems to lose fluid.

I'm now out of ideas, anybody got any?

Jason|1997 Eclipse RS

I contributed to the wiki!

happy p'ple

bad wheel cylinders???

Must be a wheel cylinders or front caliper. With the boots around the piston of the caliper, leaks can be tricky to find.

Terry

-marc

Drums in the rear.

I never thought of bad wheel cylinders. And Terry, I'll check the calipers over better when it gets warmer. Living in Northern Ohio sucks...its gonna be in the negatives tomorrow.

Thanks for the help so far guys.

Jason|1997 Eclipse RS

I contributed to the wiki!

happy p'ple

Wheel cylinders go bad all the time. Use your finger to lift the dust boot up to inspect each wheel cylinder. If those check out, your master cylinder is probably leaking into your brake booster, which you would need to replace both.

Unbolt the master and pull it back a little to inspect if it isn't obvious.

Joel Baldridge, ASE Certified Master Technician, Audi Certified Expert Technician

Although, did you take a look-see up under the dash to be *sure* your master isn't leaking in the most common way? Not hard to spot at all and the ten seconds it would take you to scope that out would be some nice peace of mind.

Also, a buddy of mine down here in Phoenix found that he head a tiny crack in the reservoir cap which was allowing fluid to leak out over time. Granted, it might be easier to spot a leak there, but I'm just saying. Akkham's Razor and all that.

The fluid will only be on the interior if the brake booster diaphram is already broke/leaking.

Joel Baldridge, ASE Certified Master Technician, Audi Certified Expert Technician