Hey guys, I'm getting my first car a '95 Dodge Avenger. The deal we have with the used car place is that they have to fix some problems with it before we buy it, and they haven't been able to fix the issue with the brakes. There it tons of travel/soft. The brake pads have been replaced as well as the master cylinder but still no luck. Any ideas? Thanks!
haha i can help im a certified brake guy!!! yeah ok well yes to me it sounds like air in the line THAT OR it is a bad assit pump, here is where my knowledge is lack i dont know if our cars use a hydraulic or a vaccum assist pump im guessing its vaccum since we are not diesels or turboed, meaning the engine has plenty of vaccum to assist you with. Is there a whoosh noise when the pedal is pressed. is it a gradual fade or is it a sudden fade?
For vaccume assist...it starts at the brake pedal. From there there is a pushrod that goes into the assis, the assist has engine vacuume suppied to it from the engine through a one way valve. When the brakes are applied the pushrod moves a piston back, that piston moves the diaphragm that it is attached to, this helps some but the real assistance is from atmospheric pressure. That piston is air tight and when it is pushed it allows air int that chamber on the one side of the diaphragm. This pressure (atmospheric air pressure) gets in there it pushed all of the diaphragm forward (due to the vacuume on the other side the pressure from the outside is much greater therefore it moves it more).
When the air gets into that chamber it makes a small woosh noise, its not much its just the air getting in there. Now if there is a lot of noise thre could be a bad seal there and the air could be getting in the whole thing therefore eleminating the assist and making a good amount of noise so thats where is huge ammount of travel would come from.
I will make a brakes how to here in the next couple of days.
« Last Edit: July 15, 2007, 06:08:45 AM by Aaron »
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