Brake question
#1
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Brake question
I just upgraded the front brakes on my 86 pickup to V6 rotors and calipers, and a larger bore MC. I bench bled the MC per the manual, and did a full system bleed on the truck as well. I still have a very spongy pedal though. With the engine off I can build up pressure on the pedal, but it takes a good ten pumps to get a firm pedal. I can hear a slight humming sound when I press the pedal though...? Is this a sign that I need to replace my brake booster?
I also have a feeling I have a bad wheel cylinder on the driver rear. I plan to do a full rebuild on both rears when funds allow though.
my main concern right now is the humming noise though...
what do you guys think?
I also have a feeling I have a bad wheel cylinder on the driver rear. I plan to do a full rebuild on both rears when funds allow though.
my main concern right now is the humming noise though...
what do you guys think?
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well the wheel cylinder checked out... thought it was leaking but it was just playing tricks on me.
As for the humming sound, I had my dad press the brakes while I listened. It is coming from the vacuum line that runs to the booster.
I still have the same problem though. Absolutely no pressure on the pedal. You can build up pressure by pumping the pedal for a little while, but as soon as you release the pedal it goes back to mush??? I am at a loss right now fellas. Anybody had a similar problem?
I know there can't be any air left in the brake lines(at least I wouldn't think there would be). I flushed the lines until all I got when I bled them was nice, fresh, clean fluid...
Thanks in advance
-Jason
As for the humming sound, I had my dad press the brakes while I listened. It is coming from the vacuum line that runs to the booster.
I still have the same problem though. Absolutely no pressure on the pedal. You can build up pressure by pumping the pedal for a little while, but as soon as you release the pedal it goes back to mush??? I am at a loss right now fellas. Anybody had a similar problem?
I know there can't be any air left in the brake lines(at least I wouldn't think there would be). I flushed the lines until all I got when I bled them was nice, fresh, clean fluid...
Thanks in advance
-Jason
Last edited by OLblue87; 11-14-2011 at 12:53 PM.
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your brake booster will only work when the engine is running if u have a hissing with the engine off then u ether have air trapped in a line of bad master cylinder...
if it is hissing when the engine is running then u have a bad booster. but you would have a veer hard peddle with in 2 pumps if there is no air in lines... to me it sounds like the master cylinder i got 2 bad ones that where brand new
if it is hissing when the engine is running then u have a bad booster. but you would have a veer hard peddle with in 2 pumps if there is no air in lines... to me it sounds like the master cylinder i got 2 bad ones that where brand new
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