vacuum pump
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vacuum pump
here lately when i start the 7.3l diesel it takes about 30 seconds for the a/c or heater blower to switch from bi level to the middle. i assume its either a weak vacuum pump or a vacuum leak. how do i go about troubleshooting a vacuum leak or a weak pump?
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From: Elk City, OK
first, are your brakes effected at all? because you will feel the bad vacuum pump there first. but as far as a general quick test, pull the vacuum line from the distribution block on the firewall and first do the finger check.... see if it holds strong to your finger when you put it over the hose. if its a strong hold, your alright. if you wanna get a better reading you can rent/buy a vacuum tester gauge. just hook it to the line and see what your getting
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brakes seem fine. they feel firm. the only thing i can say about the brakes is if i pump them 2 or 3 times in a row like if im in stop and go traffic or i'm backing up they get real stiff and i have to really push on the pedal to stop. its always been like that so i assume its normal?
Post Fiend
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I would go with oreo`s advice and get a vacuum gauge. With engine at idle you should get around 20in of vacuum. Leave gauge connected and switch engine off. If no leaks the vacuum should hold.
However if I had to guess I would say your pump is bad but a lot of $ just on a guess.
However if I had to guess I would say your pump is bad but a lot of $ just on a guess.
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From: Elk City, OK
by the brakes response, depending on how rapid you press, you can use a new pump but that's not what effecting your selector. That switch sounds like it's bad (the vacuum one that switches from one section to the other)
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I just replaced a vacuum pump on my 1990 e-350. If you want to test the vacuum, buy the tester at Harbor Freight Tools. I think it was 20 dollars or so, same as the 49 dollar Napa tester except better. The vacuum on my van should be 25 psi, instead it was 18 and the brakes were where you could tell, very hard pedal. I bought a new lifetime pump at RockAuto for 104 dollars after shipping and now the brakes work great. None of my switches were effected by the low vacuum. Good luck.
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