I have a 2001 4cyl, 5 speed Accord, 239K.

Brakes were fine yesterday, today went to the floor. Checked and found fluid was way low. Filled fluid, haven't had time to bleed them yet but haven't found any leaks. None at the master cylinder, nothing at the wheels. Where did my fluid go? There was a puddle under the car but was more towards the middle of the car which was A/C drainage I think.

I did have to adjust the parking brake last week but that shouldn't have anything to do with break fluid.

thoughts?

 

well you need to do a complete check of all of your lines. start at each caliper (check the bleeder) then work back to the master cyl.

 

I followed everything from the bleeder back to the master cylinder, unless I'm totally blind, I cannot find a leak anywhere. Going to check again this weekend after it sits in the garage for a few days, see if there is a puddle or something. It obviously has to be coming out of the system somewhere?

I just replaced front pads/rotors in March and bled the brakes then, other then that no work on them at all.

I'm perplexed.

 

It could be coming out of the master cyl where it "meets" the booster.

Hate to tell you to pull the master and look but if you don't find any leaks and the fluid is "still going somewhere" then I would check.

 

Yeah, check if it's leaking into the booster. Here's a POSSIBLE scenario, depending on how you bleed the brakes.

If you bleed the brakes by pumping the pedal, many people put a block of wood under the pedal so you don't stroke the pedal much farther than normal. The MC piston shaft might be a bit corroded out beyond it's normal range of motion. When that shaft pushes through the seal, it might tear up the seal making it leak. The vacuum booster can hold a lot of fluid before it starts leaking. Then it leaks into the intake manifold, not out onto the ground.

 

I think it might be a master cylinder/booster combo. Went out today to look at it, still no signs of any leaks at all. There was some residue on the outside of the master but that might be nothing (spillage possibly). I took the vacuum hose off, there was a little moisture but nothing I would call fluid going through it. But, tried the brake pedal and it wouldn't budge. The total opposite of what it was (all the way to the floor).

sounds like I should replace the booster/cylinder?

will look harder at it later, I work overnights and time for a nap

 

What was the fluid level?

 

Originally the fluid was empty when the pedal hit the floor. Filled it (didn't bleed - was in a parking lot), still no leaks, let it sit in the garage, still no apparent external leak, fluid went down a touch and now pedal won't budge.

 

Upon further review.

Found the leak!!! It is NOT the brake line. Obviously it was a slow leak. It is on the passenger rear caliper.

It is in the caliper I guess. Where the cable hooks into the caliper the part that it moves on the caliper, the leak is coming from there. Looks like a bushing of some sort. Can that be replaced or is it a replace the whole caliper? It is not coming from the brake line or the bleeder.

I posted from moderately adequate pictures.

 

Well rebuilding a caliper is always an option, get one that is already rebuilt, snag a used one from a bone yard.......your choice?