Tale of the missing brake fluid

KMac

KMac

Zoomin' since 2003
:
Mazda Protege5, 02
Had this issue going on two weeks now and I can not figure out where my brake fluid is going. I've had to fill it twice now and I've searched all over my car for a leak and can not find it. Any ideas? This sucks because the brake light came on again tonight which tells me I need to fill it again.
 
Check your rear drivers side caliper. That is where all mine went with no actual trace of it leaking out. I drove home late one night, good pedal pressure, woke up the next day to run to the grocery and pedal went straight to the floor. Not really sure what happened, I just replaced it with a new one.
 
Fill the master cylinder, put it on jack stands, and have a buddy get in and pump the brakes while you roll around under the car and look for the leak.
 
Could be your abs pump mines has a leak and I was loosing a lot of fluid . It resides under the battery close to the firewall. If you have an intake on the car it will be easy to spot with a flashlight , if not u have to remove the stock intake out of the way to see the abs pump
 
A bad seal in the brake booster/master cylinder can cause the fluid to be drawn through the vacuum lines and into the intake where the motor burns it off.
 
I second the brake booster if you have yet to see anything external. Unbolt the master cylinder and slide it forward, if its wet inside, replace the master. You should also replace the booster, as the brake fluid can damage the diaphragm in the booster. Not saying you must, but by the book, if the master has leaked into the booster, they both get replaced....
 
Maybe someone is stealing it to mess with your head and to get us to get you to rip your car apart. You should dust your hood for prints.
 
Stick your head under the dash and look at the clutch pedal where it goes into the master slave cylinder, could be leaking there
 
I'll check the clutch under the dash where it meets the slave for leaks. I'm really starting to lean towards the vacuum leak to the intake now. I got out of the car tonight and I swear I could smell burning oil.
 
Megazuel said:
I second the brake booster if you have yet to see anything external. Unbolt the master cylinder and slide it forward, if its wet inside, replace the master. You should also replace the booster, as the brake fluid can damage the diaphragm in the booster. Not saying you must, but by the book, if the master has leaked into the booster, they both get replaced....
Click to expand...

I will price a new one and see what I can afford.
 
Had they same type of issue on my ex-roomate's old 240sx. We looked everywhere and could not find a leak. When we unbolted the master cylinder to change it there was a little bit of fluid where it attached to the brake booster. We unbolted the brake booster too and it was atleast 1/3rd full; you could hear it sloshing around in there once we got it loose.
 
I agree with the brake booster/ master cylinder issue.
First you have to rule out a leak in hydraulic lines than plum out to each caliper.
For best results; find a friend who can pump the pedal while you get under the car and search & observe every brake line and hose...don't forget the lines to the clutch and slave cylinder, etc.
The master cylinder has a seal on the piston that if it fails would cause fluid to escape past the seal into the brake booster and in turn gets sucked into the vacuum lines, intake and eventually burned off. Pull the main vacuum line off the booster and check for signs of fluid.
Also: how does the brake pedal "feel" ? Is it soft & squishy? Or hard as a rock? either way is telling of Brake system failure.
How does the clutch "feel" any issues there?
Good luck. Let us know what it was so this post can help any future readers.
 
T-Rash said:
Check your rear drivers side caliper. That is where all mine went with no actual trace of it leaking out. I drove home late one night, good pedal pressure, woke up the next day to run to the grocery and pedal went straight to the floor. Not really sure what happened, I just replaced it with a new one.
Click to expand...

This was it, the drivers side caliper seal where the parking brake pulls. When I first looked the car was wet (typical Oregon Weather) so I could not tell for sure last week. This morning I put it up on stands and crawled around on my back looking specifically at all connections and this time the underside was dry except for drivers side back caliper. Had my lovely assistant (wife) pump the brake pedal hard and it just pours from the seal. Every time the E-brake is pulled too, drip drip drip. So now to replace the back caliper. Here are a couple of pictures.

36EF0A9E-71C2-432C-99FE-CF00AED405EB-4892-00000507C6258CD7.jpg


D24FEDFD-0BCC-4200-BE22-6AC66AB12E90-4892-00000507CA547BA3.jpg
 
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Good catch man. Caliper is an easy Remove & Replace. Clean those brake pads & Rotors real good w/ brake-clean you don't want brake fade do to contaminated brake pads.
 
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