so, i just did a motor swap..everything seems to be hooked up and i didnt unhook the brakes ...but its as if you try to push the brake with no key in the car and it slowly gets harder to push...its fine for the first time you push it then its way way at the top and hard..do i have to bleed them?
what would i be looking for there? sorry im not sure what it all looks like
Jason Preissler wrote:what would i be looking for there? sorry im not sure what it all looks like
it would look like a crack/hole/worn hose going to the brake power booster.
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without the car running the brakes should be really fricken hard to push down. thus is the nature of vacuum assisted brakes, they're only assisted when the motor is running. so in essence, you have no problem.
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Leafy wrote:without the car running the brakes should be really fricken hard to push down. thus is the nature of vacuum assisted brakes, they're only assisted when the motor is running. so in essence, you have no problem.
reread the original post. there is indeed a problem.
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Rich Grayo Jr. wrote:Leafy wrote:without the car running the brakes should be really fricken hard to push down. thus is the nature of vacuum assisted brakes, they're only assisted when the motor is running. so in essence, you have no problem.
reread the original post. there is indeed a problem.
I dont see a problem. with the car off (unless somehow he has the car running without the key in it), its not producing any new vacuum, and when you keep pressing the brake pedal with the car off you use up that vacuum, if you dont believe me a short walk out to your car will prove me right. IF the car was on and he was having the same symptom then there'd be a problem, and it'd be some sort of lack of vacuum, either a kinked vacuum line to the brake booster, running huge cams, or a vacuum leak.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Leafy wrote:Rich Grayo Jr. wrote:Leafy wrote:without the car running the brakes should be really fricken hard to push down. thus is the nature of vacuum assisted brakes, they're only assisted when the motor is running. so in essence, you have no problem.
reread the original post. there is indeed a problem.
I dont see a problem. with the car off (unless somehow he has the car running without the key in it), its not producing any new vacuum, and when you keep pressing the brake pedal with the car off you use up that vacuum, if you dont believe me a short walk out to your car will prove me right. IF the car was on and he was having the same symptom then there'd be a problem, and it'd be some sort of lack of vacuum, either a kinked vacuum line to the brake booster, running huge cams, or a vacuum leak.
Jason Preissler wrote:but its as if you try to push the brake with no key in the car and it slowly gets harder to push
implies the car is running, not off.
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yes it it while it is running...but it feels like when the pedal does when the car is off..sorr for the misunderstanding
Yup, vacuum leak, or rather, lack of vacuum getting to the booster.
I have also seen where the ports in the booster have gotten clogged. Where the vacuum port is open to both sides of the booster at rest, but when you hit the brakes the pedal side atmospheric port doesn't allow air to enter the backside of the diaphragm. You could also have the backside vacuum port not blocking off when you hit the pedal which will apply vacuum to both sides of the diaphragm, however when this happens typically(typically because the atm. port will likely work) you can notice your engine sucking air thru the booster and will see this as a high idle condition while your foot is on the brake.....well, until the IAC tightens up to slow that back down. This can be miss-diagnosed because you remember your engine increasing RPM whenever you hit the brakes normally, however, to diagnose this you will notice the rpm will drop lower than idle when you let off the pedal after the engine has returned to normal idle when your foot is on the pedal....meaning the IAC has cranked down to adjust for the air coming thru the booster, then when you let off the pedal that air supply is stopped when the port closes. This will result in a slump of the idle until the IAC rebounds back open to it's proper location for normal idle.......that is the difference you'll see.
If that makes no since let me know, I can walk thru it better. Obviously you only suspect the booster till you KNOW that the vacuum line to the booster isn't the problem....that is definitely the first place to look and the likely suspect. I'm just throwing this out there as a second 'possible, but un-likely cause' in case you find the vacuum line to not be the problem.
Edited 1 time(s). Last edited Thursday, March 04, 2010 6:07 AM
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well guys i figured out my brake problem...turns out the vacuum hose that goes to the booster i guess was clogged...turns out when i got my motor..they plugged all the holes with red caps..and whoever put that hose onto the motor put it on right over the cap lol..well thank god for stupid cheap mistakes!! shes up and running now...just that one connecter that i think is the backup lights
