BRAKE FLUID LOW?!?!?!?!?! (need help asap!)

[t3-svo]

I noticed today that my brake pedal wasnt feeling as stiff as it usually is. I noticed that my fluid resevoir was low in the front half of it. The back half was full to the top with fluid. I checked all of the calipers and none of them are leaking. neither are the brake lines going to the calipers. Could this "loss?" of fluid be caused by the outside temperature change. Its gotten colder so is the fluid contracting?

Also i do hear an excessive whoosh noise when i push down the brake pedal. could this be a bad brake booster?

I need help ASAP because this is a daily driver and i dont want the brakes to go out on me!

p.s. its an 86 svo.

 

[Red_LX]

There's a chance the master cylinder could be leaking back into the brake booster, it's not uncommon...

 

[351wcoupe]

yeah that was my first thought as well.
Don't do anything on the brake system without a can on PB blaster or somekind of rust catalyst and some patience.

take the two nuts loose that hold the master cylinder to the booster and go from there.

 

[Stinger]

You did fill it back up with fluid right?

My SVO "wooshes" as well but doesn't leak fluid...

 

[Shawneebear93]

You did fill it back up with fluid right?

My SVO "wooshes" as well but doesn't leak fluid...

 

[t3-svo]

ok....

I added more fluid but the problem still persists. the real problem is when i hit the brakes. i push down the pedal and i have to go about 3/4 of the way down before the car really starts to brake. and i have to push it hard. i checked the fluid today and it hasnt gone down since i refilled it. but the braking is still bad. do you think that the fluid is leaking into the booster?\

It has new calipers, pads, hoses, master cylinder and fluid on it from about 5 months ago. still the original brake booster.

 

[86bluecobra]

i would say it is a booster related issue.

 

[351wcoupe]

" IF " the fluid isn't going down maybe it was low and got air to the front. fill it up full and barely crack the bleeders. Let them sit several hours and keep an eye on the fluid level. Tighten the bleeders and so if you gained any pedal.

 

[t3-svo]

?

the fluid does go down. and there is excessive pedal play.

if there are no external leaks does this mean that there could be internal leaks? Could the master cylinder be leaking internally? Like the seals inside the master cylinder be leaking into the booster? i dont know much about the whole internal assembly.

 

[Red_LX]

if there are no external leaks does this mean that there could be internal leaks? Could the master cylinder be leaking internally? Like the seals inside the master cylinder be leaking into the booster? i dont know much about the whole internal assembly.

Yes.

Did you try unbolting the MC and pulling it away from the booster a bit like Matt suggested? If you do that, you should be able to tell if fluid is coming out of the back of the MC or not.

 

[351wcoupe]

I was looking for an exploded view but couldn't find one I was happy with. If the fluid is continually going down after you add it, then it has to be leaking out somewhere. An internal leak causes a soft pedal but the fluid level stays constant.
If you're loosing fluid but see no leaks, seperate the MC from the boost and take a peak.

Edit: you beat me to it.

Also don't confuse an internal leak with a back into the booster they are different, but the fix is the same for both.