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Posted by East Bay 50 (Member # 8081) on
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I have a 91 mustang with a heads and cam stroker. the problem I am having is that my brakes dont really work unless I have the rpms around 2k. could this be because I have a large cam or possibly a bad brake booster? or something else? how can i tell which it is? thanks!
Posted by SS396 chevelle (Member # 7277) on
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Stock brakes?an is the pedal hard
Posted by East Bay 50 (Member # 8081) on
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quote:
Originally posted by SS396 chevelle:
Stock brakes?an is the pedal hard
brakes are not that hard really. they are stock though. i have to be in rpms for them to really work good
[ December 28, 2011, 03:18 PM: Message edited by: East Bay 50 ]
Posted by SS396 chevelle (Member # 7277) on
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Stock brakes on these foxbody suck balls an stopping may take more time the your use to if dont drive it everyday.also changing the check valve in the power booster may help some an make sure the rears are adjusted
Posted by Blind (Member # 3052) on
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if the pedal isn't hard it's not a vacuum/cam size issue.
Flush/bleed the brake fluid and adjust the drums.
Posted by East Bay 50 (Member # 8081) on
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quote:
Originally posted by Blind:
if the pedal isn't hard it's not a vacuum/cam size issue.
Flush/bleed the brake fluid and adjust the drums.
actually< i just checked it and it is kinda hard until i step on the gas pedal to get it in the rpms
Posted by 5.0 LsX (Member # 10017) on
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not enough vacuum to the booster,assuming the booster is ok, do you have a vacuum gauge? whats the vacuum at?
Posted by 93coupessp (Member # 8418) on
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Sounds like not enough vacuum
Posted by East Bay 50 (Member # 8081) on
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ill buy a gauge tomorrow and post up what i find
Posted by East Bay 50 (Member # 8081) on
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vacum is at 5 and does not go up unless I step on the gas pedal. ive had this problem ever since i swapped cams. could the cam be whats taking away all my vacuum or would it be the brake booster?
Posted by Greasy (Member # 5258) on
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Are you sure you don't have a massive vacuum leak? Maybe the intake gasket didn't seal well? What cam did you swap to?
Posted by East Bay 50 (Member # 8081) on
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quote:
Originally posted by Greasy:
Are you sure you don't have a massive vacuum leak? Maybe the intake gasket didn't seal well? What cam did you swap to?
its a pretty decent size custom cam. i dont think i have any vaccum leaks
Posted by Blind (Member # 3052) on
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well a stock 5.0 makes about 18" of vacuum at idle. My TFS stage1 makes ~13" if I have the idle rpm set down under 850, around 900rpm it makes ~16".
So with 5" of vacuum, that cam is probably below the level of what I would consider street drivable if it's a manual, it probably doesn't even move until 2k rpm's.
or you have a very bad vacuum leak, like pvc valve missing or forgot the gasket between the upper/lower intake sized vacuum leak.
smoke test it, IMO.
[ December 30, 2011, 09:55 PM: Message edited by: Blind ]
Posted by East Bay 50 (Member # 8081) on
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quote:
Originally posted by Blind:
well a stock 5.0 makes about 18" of vacuum at idle. My TFS stage1 makes ~13" if I have the idle rpm set down under 850, around 900rpm it makes ~16".
So with 5" of vacuum, that cam is probably below the level of what I would consider street drivable if it's a manual, it probably doesn't even move until 2k rpm's.
or you have a very bad vacuum leak, like pvc valve missing or forgot the gasket between the upper/lower intake sized vacuum leak.
smoke test it, IMO.
smoke test? whats that?
Posted by Greasy (Member # 5258) on
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It's a machine that gets hooked up to a vacuum line and puts smoke in the engine. It makes it really easy to find vacuum leaks.
Posted by East Bay 50 (Member # 8081) on
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quote:
Originally posted by Greasy:
It's a machine that gets hooked up to a vacuum line and puts smoke in the engine. It makes it really easy to find vacuum leaks.
Can u buy it at the parts store? Any idea on how much it costs?
Posted by Greasy (Member # 5258) on
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You'll probably have to go to a shop to have it done. I've never seen one you can buy at the parts store, but I also never looked for one.
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