I have a 1998 Civic EX 2dr Auto without ABS, with rear drums. Has 170k on her.

2 years ago I did read brake lines, as I live up north and salt collected in that track and I had the puddle of fluid under the car etc.

I did rear lines with line from advance auto, and used the standard brass connectors in between sections. I used 2 60s on the driver side and 2 60s plus a 20 on the passenger side.

Over the past few months the level of fluid in the mc continues to drop, I refill, it brakes fine, then I keep adding every two weeks or so it is down 1/2 from he top fill mark.

Now I have checked for leaks... Rear drums, shoes, cylinders are 3 years old. No leaks. Traced the lines, and connectors (which is where I woulda bet my money... If I was a betting man) but no leaks. I did front pads and rotors since I noticed the fluid leaking, no leaks at the calipers or from the front lines. I don't see any fluid on the ground, just oil from the rear main seal.

What do I do? This is driving me crazy. How can fluid vanish from a closed system?!

 

Is there fluid on the the brake booster under the master cylinder?

 

I looked there too to see if there was an internal seal mc leak... Nothing is dripping down the firewall.

 

they can also leak into the booster from the back of the master
and fill the booster full of fluid

 

remove the vacuum line and check in the booster i have found them half full of brake fluid before.

 

Ok I will check that vaccum line.

So I drove the car tonight and the car pulled severely to the left when braking. Would this hint at a problem I am having?

 

It seems your problem lies with the right front caliper/lines. Check them closely.

 

also check your right front caliper piston seal. my seal was completely torn recently from overheating the brakes and was leaking from around the caliper piston.

 

I will pull that wheel tomorrow evening after work!

So when it pulls to one side the affected or damaged part is the opposite side? I guess that makes sense because all the braking force is coming from the left pulling the car to the left.

Interested to see what everything looks like in there.