loeryder21

I work for the military and had the car sitting for about 6 months. Came back and she started right up but brake pedal went right to the floor. I took the front system apart (still have drums in the rear) and so far i am not getting any fluid from the lines at the calipers. Meaning i disconnected the caliper, pumped the brakes and nothing. dry. The lines still seem true and no visible leaks anywhere. Im thinking maybe its the proportioning valve mounted to the body but wanted a second opinion.
Thanks

StalkerGT

Could be the master cylinder...I had a similar problem on a vw I had when I was younger

loeryder21

I took it out and cleaned everything, it looks like its working as it should. so im looking at problems further down the line. About how long would it take to completely replenish a fluid system if it is drained? im thinking i havent given it enough pumps yet.

petrock

It all depends on how you are pumping the fluid through the system. If your doing it manually via the brake pedal it will take a while. If your doing it with a mix of gravity-bleeding & the brake pedal it will be a little quicker. If you hook up a vacuum pump to the bleeder on the caliper and suck the fluid through the system it should be a couple minutes per caliper. You can pick up a hand vacuum pump, and some clear vinyl hose from most auto parts stores fairly inexpensively. Very handy tool… Good luck...

9550

is there a way to fill it through the bleed valve at the caliper? that would be ideal, yes?

Derf00

noooo, dont reverse fill! you dont want all of the crap in the caliper working its way into your system. plus you will be mor likely to get air trapped in your system. Proportioning valves dont normally go bad.

my money is on the seals in the master cylinder are bad. When you press the brake pedal, instead of fluid being pushed into the lines, it just sits there...thus no pressure (pedal to the floor) and no fluid movement.

dawson1112

^I agree with Derf00,,

6 months isn't a long time for the car to sit, if there was brake fluid in the reservoir, and no signs of it leaking out on the floor any place Id go with bad seals in the MC. Brake fluid doesn't just evaporate or magically disappear it has to go someplace.

And the only way to get that much air in the line is that the fluid leaked out and was replaced with air. The proportioning valve ( IF ) it went bad , would cause your rear brakes to lock up when you hit the brakes, because all it does is control the amount of pressure that is sent to the front and back. Always have more brake pressure on the front lines as this is where 70 % of your braking power is applied.
It also acts as a safety in case of a line failure. Say your front brake line ruptures , the pressure loss on the front causes the proportioning valve to partly close off the front line and send power to the rear brakes , while your pedal may go to the floor the rear brakes will still have some stopping power

If the pedal goes to the floor it it either because there is so much air in the line that it cant build pressure , or the seals are bad and its not pushing fluid.

9550

really? more likely to get air trapped? i would think it would be less likely?
i have never done it either way, but i thought i recall researching it for doing motorcycle brakes and that was the best way. maybe motorcycle systems are different or maybe i am misremembering. but i did do it as you guys suggest when i did the motorcycle lines (with a hand vacuum pump) so i guess i didnt screw that up.