mystery brake fluid leak.

[vash]

ok, i have rebuilt all four calipers, changed the rubber lines, bled the system. seems like everytime i check the reservoir, the brake fluid is low. today it was very low. i have two lines coming from the reservior, i assume the back one is for the rear brakes. seems like the leak is coming from this half of the system. i cant find the leak! no wet spots, calipers are all dry, WTF? maybe my master cylinder? i dont see a leak on the belly pan.

cliff

[targa911man]

Bleeder valve(s) loose/cross-threaded? Why do you say the leak is from the back line? Try bleeding again and then apply the brakes hard several times with the car standing still. Then look for fluid on the ground and at all connections.

[vash]

i looked at the two lines coming from the brake fluid reservior. the level was so low that the back line was almost empty. the front line was still full to the inlet of the line inside the reservior. so a assumed the leak was in the back half of the system. i just took the floor cover from the backseat feet area and i was wet with some fluid inside. i cleaned it up and will check for the telltale blue ATE color. it didnt smell like brake fluid, but that didnt seem like a good indication. i am afraid that if i dont have a puddle on the garage floor, the leak could be in a line going to the front to back. that would be hell. and that would mean i have the puddle of hell of brake fluid held up inside the car somewhere. i grimace at the thought. all my connections are clean and dry. so are the bleeder valves. by the way, your bike pump idea was SWEET!

[targa911man]

Glad the pump post helped. Unfortunately (fortunately for me) I have not had to trace the brake lines for leaks. Maybe a PM to John Walker would be useful.

[vash]

just bugged JW. thanks.

[vash]

ok, just thinking to myself. i can pump up the brake pedal hard with repeated presses, and i can hold it there. i bet the leak is before the master cylinder. i guess i am climbing under AGAIN.

i think i am going to change my board name to Sisyphus, the poor dude pushing the rock repeatedly up the hill in greed mythology.

[vash]

opps "greek mythology"

[AFJuvat]

The brake light switches will fail and leak over time - the fluid drips into the luggage compartment and never gets spotted.

AFJuvat

[makaio]

Pull your driver's side pedal board and have a look. I'll bet $1 that is where you find your leak.

[vash]

thanks guys. i guess i am GOING BACK IN! well i am learning and in some sick and twisted way, it is fun. too bad it wasnt FREE parts. makaio, i wouldnt bet against you. i think you are right. so pedal board, the wooden panel by the pedal cluster? what is down there?

cliff

[avendlerdp]

I had a bear of a leak a few months back and it turned out that the brake line wore through on somthing in the tunnel. When I pulled the line out I found two other spots where it was rubbing on something in there. It took 30 years to leak but it is a design flaw. If all else fails check that.

Alex

[makaio]

Cliff, removing the pedal board is a snap. All you need to do is remove the carpeting and/or mat, use a 10mm socket to remove the holding nut, and snap off the throttle linkage. Then if your MC is leaking it should be fairly obvious. It will puddle around the pedal cluster, and should be a trail coming down from the top.

Everyone always say to be carefull with brake fluid around paint, but remeber you need to wear safety glasses when dealing with it as well.

[3.2 CAB]

If your car has power brakes, I have seen bad M/C orings/seals fail and leak into the brake booster. Sometimes it will stay there and not run out till it has filled it up enough to get out of the pedal shaft hole.

[makaio]

Good point 3.2 CAB. I did see this once before on a frineds SC.

[vash]

thank you makaio, your method of looking into the floor pan cover will save me the trouble of jacking up the car, removing bellypan...blah, blah... i will post my findings. and 3.2 good point, but unfortuanaly the only power booster my car has is for me to push harder thanks guys.

by the way, have you ever put the front wheel of a 911 on ramps? the jack stands on the ends of the torsion bars doesnt leave much room for my chubby A$$ to squeeze through and do the work. i really am not chubby, just sorta claustrophobic, i get anxious squeezed between the jack stands. maybe this is a diff post. thanks.

[3.2 CAB]

I have had mine all 4 tires on ramps, jacked it up enough to get the tires on the platforms. Can't drive mine on though, too low, front valance would get cratered. Worked great, really good for changing shocks.

[vash]

thanks 3.2! sounds like a plan.

[elbean]

unfixed,
Take a look in your tunnel as Alex stated. i too had a similar problem. i don't know if it was worn after 35 years or if it happen when my mechanic changed to a short shifter. Make sure you dilute with water and or cleaner and towel dry. Good Luck

[vash]

i would post the picture, but it is way too hideous.
i pulled the wooden pedal board, and it looked like a team of smurfs pee'd all over the pedal cluster. the indention in the floorboard where the cluster mechanism sits was completely submerged. i had to laugh. it was the hardest thing to clean up. 30 years of dirt, mixed with (i would estimate) 3 reserviors full of blue ATE. lesson learned: if the i ever find the reservior empty and there is no visible leak on the garage floor, DONT refill the thing two more times! if this ever happens to you guys, use a shop vac with a small clear plastic hose taped into the big hose, simple green, and two rolls of paper towels. i guess it could be worse, it wasnt in the tunnel.

thanks, i guess i am ordering a new MC.

cliff

[makaio]

Glad you found the problem Cliff.

I guess I didn't win anything since nobody took me up on the bet.