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Best way to test/change fuel pump

This is a discussion on Best way to test/change fuel pump within the Technical / Maintenance forums, part of the General Discussion category; 98 k1500 5.7l Pumps whining pretty good, wats the best method to test it? put a regulator on it and ...

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    Peg
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    Best way to test/change fuel pump


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    98 k1500 5.7l Pumps whining pretty good, wats the best method to test it? put a regulator on it and check the pressure at different rpm's would be my best guess. What should the pressure be around? How much drop is normal?

    Second question is, whats the best way to change these things?

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    RAGMC ragmc's Avatar
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    Re: Best way to test/change fuel pump

    If its whining Id change it out before it leaves you stranded somewhere. I have always droped the tank but there are some that say pulling the bed is easier to change tham out.

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    Hired Goon Aloicious's Avatar
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    Re: Best way to test/change fuel pump

    get a gauge and test the pressure, key on engine off should be about 58-60psi, idle should be around 55-58 psi. if you're able to safely watch the gauge on a short drive, you don't want it drop much below 55psi.

    I'm with ragmc though, if it's whining, I'd get in there and change it before you're forced to do so on the side of the road or something.

    use ONLY a delco or delphi pump, and it's also wise to change the sending unit too. do NOT use a parts store pump. otherwise you'll be changing it again in a few months.

    I've dropped the tank, and pulled the bed. they're both about the same difficulty. I probably prefer pulling the bed personally.

    1996 C1500 ECSB 5.7L AKA the "LS31", distributorless w/LS2 coils, RHS Heads, ZZ4 Cam, T56 6 speed, 12200411 PCM, 4.88s...Coming soon: forged twin turbo 383..

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    Re: Best way to test/change fuel pump

    OBS trucks always whine, they are a very loud pump and its perfectly normal. you can check fuel pressure at the port on the fuel line going into the manifold. Key on engine off should read 55-60psi on the first on cycle, and should hold it there, and not bleed down.
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    Re: Best way to test/change fuel pump

    Quote Originally Posted by ragmc View Post
    If its whining Id change it out before it leaves you stranded somewhere. I have always droped the tank but there are some that say pulling the bed is easier to change tham out.
    All 3 of my chevy's whine when key is turned to on for a few seconds, even the new pump whines(not as loud as the old ones). Reason most of us lift the bed is because its easier to disconnect the fuel lines with the bed lifted off. Plus its faster then messing the straps(which or either bent or have rusted bolts)and working in a tight space to unhook the fuel lines.

    P.S: Seating in a chair removing and installing the fuel pump is better then laying on the ground any day.
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    Peg
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    Re: Best way to test/change fuel pump

    Thanks for the input. Ill be testing the pressure tomorrow, just too cold to do it today. The pumps always whined since i bought the truck half a year ago, i just dont want to get stranded somewhere if it does go. Ill be keeping a mallet with me from now on..

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    Re: Best way to test/change fuel pump

    What they said for testing.
    Like said above, I drop the tank, but most will tell you to pull the bed.
    Tank you can do by yourself half full or full with a jack just fine. The bed with a cherry picker or some lifting device by yourself. Otherwise to pull the bed you need some help.


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    Hired Goon Aloicious's Avatar
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    Re: Best way to test/change fuel pump

    Hearing the pump is normal, but developing a whine that wasn't there before or if the 'normal' pump noise changes over time it can definitely be an indication of a failing pump.

    I'd definitely test the pressure before throwing money at it.

    1996 C1500 ECSB 5.7L AKA the "LS31", distributorless w/LS2 coils, RHS Heads, ZZ4 Cam, T56 6 speed, 12200411 PCM, 4.88s...Coming soon: forged twin turbo 383..

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    Re: Best way to test/change fuel pump

    Every one Ive come across has whined to some degree. Its when they stop whining that I worry.

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    Re: Best way to test/change fuel pump

    Quote Originally Posted by 454/4X4 View Post
    Its when they stop whining that I worry.
    Best quote for the win!

    P.S: That quote would count for a woman also
    Last edited by wayne220; 02-26-2012 at 11:31 AM.
    1988 C1500
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    Quote Originally Posted by ericlw View Post
    Lack of Preparation on YOUR Part does NOT Constitute an Emergency on ours

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    FastOrange BlacK20's Avatar
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    Re: Best way to test/change fuel pump

    Quote Originally Posted by Botan View Post
    OBS trucks always whine, they are a very loud pump and its perfectly normal. you can check fuel pressure at the port on the fuel line going into the manifold. Key on engine off should read 55-60psi on the first on cycle, and should hold it there, and not bleed down.
    i have owned 5 obs trucks, whine has always been a sign that pumps going out... all my trucks with good pumps you have to listen close to even hear the pump.


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    Re: Best way to test/change fuel pump

    Quote Originally Posted by BlacK20 View Post
    i have owned 5 obs trucks, whine has always been a sign that pumps going out... all my trucks with good pumps you have to listen close to even hear the pump.
    I can stand outside the truck door, turn the key and hear my brand smacking new pump whine, but i guess every one's hearing is different. Even a new pump will get a louder whine as it age's, just the nature of the beast. If people really think a chevy fuel pump whining when key is first turned on is a sign the fuel pump is going out or bad... Then I'm opening a parts store with just chevy fuel pumps.
    1988 C1500
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    Quote Originally Posted by ericlw View Post
    Lack of Preparation on YOUR Part does NOT Constitute an Emergency on ours

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    FastOrange BlacK20's Avatar
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    Re: Best way to test/change fuel pump

    Quote Originally Posted by wayne220 View Post
    I can stand outside the truck door, turn the key and hear my brand smacking new pump whine, but i guess every one's hearing is different. Even a new pump will get a louder whine as it age's, just the nature of the beast. If people really think a chevy fuel pump whining when key is first turned on is a sign the fuel pump is going out or bad... Then I'm opening a parts store with just chevy fuel pumps.
    all of the ones ive had are pretty damn quiet, then again, ive always owned TBI trucks.


    1978 K20 RCLB, 400 SBC, 4-Speed, Lifted
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    Re: Best way to test/change fuel pump

    Quote Originally Posted by BlacK20 View Post
    all of the ones ive had are pretty damn quiet, then again, ive always owned TBI trucks.
    New pumps or quit, but they still whine up when key is turned on(rather you hear it or not). TBI, carb etc all the same deal. Why or we still debating this lol

    Anyhow here is a youtube video which is pretty funny to watch, but shows how to change pump with bed off way. http://www.youtube.com/watch?v=kiODvqs-X9M

    That is a newer chevy so dropping the tank would have been easier, but the guy was entertaining to watch so i added it. On the older Chevy truck the fuel lines run on the driver side down between tank and frame rail which is why i like to pull the bed(or block it up).

    P.S: Listen to the NEW pump whine up when key is turned on.
    Last edited by wayne220; 02-26-2012 at 03:24 PM.
    1988 C1500
    1997 F250
    Quote Originally Posted by ericlw View Post
    Lack of Preparation on YOUR Part does NOT Constitute an Emergency on ours

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    FastOrange BlacK20's Avatar
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    Re: Best way to test/change fuel pump

    Quote Originally Posted by wayne220 View Post
    New pumps or quit, but they still whine up when key is turned on(rather you hear it or not). TBI, carb etc all the same deal. Why or we still debating this lol

    Anyhow here is a youtube video which is pretty funny to watch, but shows how to change pump with bed off way. http://www.youtube.com/watch?v=kiODvqs-X9M

    That is a newer chevy so dropping the tank would have been easier, but the guy was entertaining to watch so i added it. On the older Chevy truck the fuel lines run on the driver side down between tank and frame rail which is why i like to pull the bed(or block it up).

    P.S: Listen to the NEW pump whine up when key is turned on.
    1) i didn't say that my pumps dont whine at all, they do, they whine just about as loud as that truck in the video, what im saying, is a overly loud pump, usually means its on its way out!
    2) why i mention TBI vs Vortec, is Vortec runs at higher pressure and use a different pump.
    3) BTW, a carb truck usually has a block mounted pump, no whine there.


    1978 K20 RCLB, 400 SBC, 4-Speed, Lifted
    1998 Pontiac Grand Prix GT, Coupe

 

 

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