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4.8 2004 vacuum pump

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Old 08-16-2004, 06:25 PM
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i have a vacume gauge too. it seems to kick on at about 7in of vacume. my cam runs about 10-13" most of the time but when cold it dips down prety low and kicks the pump on.
Old 08-16-2004, 06:39 PM
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well snakeater was talking about wanting a pump for his truck cause of the cam. is this what he is talking about or is there something else i need. if ikicks on for your when you have low vacuum i would think this is what its for. what do you mean when you say crank case vacuum are you talking about like a catch can to help vent crank case presure for high rpm. i know its not for that.
Old 08-16-2004, 06:41 PM
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or is this strickly for the brake system.
Old 08-16-2004, 06:46 PM
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it is strickly for the brake system, i think it is there to maintain brakes in case the motor dies while moving.
Old 08-16-2004, 07:30 PM
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so what if we tap into it for other uses???
Old 08-17-2004, 08:31 AM
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Mike, just give me your pump and i'll be set. hahaha

Parish, my truck wants to die when its in gear WITH the brakes taking up all the vacume. Will one of these pumps or a simular one help?
Old 08-17-2004, 10:29 AM
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Well that's DAMN COOL. I always wondered what I was scraping my forearm on when i'm digging around on the drivers side there.

What if like this weekend, my engine stalls while I'm rolling down the road... Of course you only get like three pumps of the brake pedal before the vacuum in the booster is all used up. I assume that with the ignition on, this thing will kick on and be able to keep my power brakes working correctly?

I didn't feel/hear it, because my motor crapped out at very low speeds in parking lots so I didn't use much of the brakes.
Old 08-17-2004, 04:14 PM
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Originally Posted by Snake Eater
Mike, just give me your pump and i'll be set. hahaha

Parish, my truck wants to die when its in gear WITH the brakes taking up all the vacume. Will one of these pumps or a simular one help?
i never heard of the brakes causing a motor to die. all the pump will do is help your brakes, it wont help your truck run any better.
Old 08-19-2004, 06:07 AM
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It runs and idles great. Stays at a constant 750-800rpms at idle in park, nuetral, or in gear with the E-brake on. The only time it bogs down is when its in gear with the brakes on. Then it drops to 300-400rpms, and sometimes stalls out.

What else could be causing the drop in rpms, only in gear with the breaks on?
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