low brake pedal at idle/low rpm??

ddw350

Registered User
after following some advice earlier and doing some things other members have said[cleaning the booster,checking all fittings...]i still have a very low pedal at idle and low rpms.theres hardly any resistance for the first 2 or so inches,then you go a little further and they work.but it goes WAY lower than it used to and triggers the firm ride light.once i start driving the brakes are great.its still idling up when you hit the brakes a few times at idle.i have a new master cylinder that was vaccum bled along with each wheel bled to ensure no air in the system.this did nothing...also before i did this ,there was brake fluid dripping insid the car.another member said it was from the bad master cylinder.ive been working on this thing for like 10 hours all together!!
 
we bled it at the master cyl forever,then he vaccum bled the whole system,i dont know how much more bleeding it will take!this problem came all of a sudden last saturday,and after all this,it still feels exactly the same.i believe the low vaccum idea,wonder how and why this happens?
 
Maybe I can save you some time. Stick your ear under the dash down by the brake pedal and turn your head so you're ear is directed at the area where the Booster enters the interior wall. You should hear a hissing noise if a vacuum leak is present. Replace the Power Brake Booster, and make sure all brake pads are new, and then see what kind of RPM you have, and how much pedal you have. Low vacuum in a booster will feel like a bad master cylinder, but the car will stop fine with the need for increased effort on the pedal. This is one vacuum leak that actually lowers RPM.

discipled1
 
i havent listened for a leak yet,but it must be from low vaccum causing the low pedal at idle...the rpms actually raise when you repeatedly hit the pedal,then they lower back down to regular idle speedi thought a bad boosetr made the brakes stiff,like not having power brakes..imgonna listen for the leak,also ill check the vaccum line to the booster to make sure its ok,and the little check valve in the booster...thanks
 
i didnt hear anything noticable listening for a leak under the dash at the booster,couldnt you spray some ether around there and listen for the motor to rev up..seems like that would tell you if it is leaking,think i'll take it to a shop i know that does alot of ford cars and trucks..this may require a higher power than me .....this car pisses me off sometimes!! but i like it!!! if you guys have any other suggestions please let me know...thanks
 
i called a local shop [i know them personally] and asked if they could fit me in on wednesday.i cant seem to figure this out.usually if i fool with something long enough,i'll figure it out,at least partially...not this time,i hate to drive 8 hours to the beach and half way there i lose all braking!!
 
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