High Pitched Whine From Behind Cab

[Treemonkey1000]

She probably says the same things about you to her friends..

 

[Dargo]

She probably says the same things about you to her friends..

I know my better half does that.

 

[workinallthetime]

Bump the ignition a couple times and see if you hear it, fuel pump should run for 3 seconds. Jump the fuel pump relay and se if you hear the same noise.
I have seen these run anywhere from 300 miles to 50k miles screemin like crazy.
GM fuel pump $470.00 walk in price, $325.00 wholsale price, sold as complete unit for your year, and I am asuming you have a 5.3 engine.
The reason the body is so big on these pumps and they are sold as a unit and not just a pump like the old days is: this pump runs at 55-60 psi and uses the body to retain fuel around the pump to help keep it cool. Resistance due to a plugged fuel filter is as bad on these as running it out of fuel or low on fuel all the time.

DROPPIN THE TAKE ON THIS MODEL IS A WASTE OF TIME AND A GOOD WAY TO GET HURT, OR TEAR SOMETHING UP!!!!!!

1 park on level ground with plenty of room to move around the truck
2 empty the bed
3 remove 10mm ground strap between bed and cab
4 remove the 3 7mm screws from the black housing around the fuel cap
5 unplug the 3 connectors on the drivers side under the bed
6 remove the 6 bolts that hold the frame to the bed 18mm (i think)
7 cover bumper on each side with towels
8 pick the bed up and set back on the tires and bumper. 2 to 4 guys can do this, or use your fel to lift it up by the hooks in the 4 corners of the bed, its really not that heavy.
9 use compressed air to bolw all the dirt off the top of the sender
10 remove connectors and fuel lines, fuel lines are 2 sizes and you will need some quick disconnect tools to remove them.
11 look at the retaining ring, one way it comes off the other way it does not, using a chisel, or screw driver and hammer pound the thing from an agle to turn it off.
12 pull the sender and install the new one, then reasemble.

Im pretty sure thats it, pulling all this from memory

holler if ya need anything

this entire process in and out was about 30 minutes in the shop!!

 

[Iplayfarmer]

Bump the ignition a couple times and see if you hear it, fuel pump should run for 3 seconds. Jump the fuel pump relay and se if you hear the same noise.
I have seen these run anywhere from 300 miles to 50k miles screemin like crazy.
GM fuel pump $470.00 walk in price, $325.00 wholsale price, sold as complete unit for your year, and I am asuming you have a 5.3 engine.
The reason the body is so big on these pumps and they are sold as a unit and not just a pump like the old days is: this pump runs at 55-60 psi and uses the body to retain fuel around the pump to help keep it cool. Resistance due to a plugged fuel filter is as bad on these as running it out of fuel or low on fuel all the time.

DROPPIN THE TAKE ON THIS MODEL IS A WASTE OF TIME AND A GOOD WAY TO GET HURT, OR TEAR SOMETHING UP!!!!!!

1 park on level ground with plenty of room to move around the truck
2 empty the bed
3 remove 10mm ground strap between bed and cab
4 remove the 3 7mm screws from the black housing around the fuel cap
5 unplug the 3 connectors on the drivers side under the bed
6 remove the 6 bolts that hold the frame to the bed 18mm (i think)
7 cover bumper on each side with towels
8 pick the bed up and set back on the tires and bumper. 2 to 4 guys can do this, or use your fel to lift it up by the hooks in the 4 corners of the bed, its really not that heavy.
9 use compressed air to bolw all the dirt off the top of the sender
10 remove connectors and fuel lines, fuel lines are 2 sizes and you will need some quick disconnect tools to remove them.
11 look at the retaining ring, one way it comes off the other way it does not, using a chisel, or screw driver and hammer pound the thing from an agle to turn it off.
12 pull the sender and install the new one, then reasemble.

Im pretty sure thats it, pulling all this from memory

holler if ya need anything

this entire process in and out was about 30 minutes in the shop!!

Thanks for that step-by-step. Mine will have a few more steps because I also have a fifth wheel hitch that I'll have to unbolt from the bed and frame.

Also, isn't there somewhere in there that the fuel filler tube has to be disconnected from something?

 

[Diamondpilot]

Thanks for that step-by-step. Mine will have a few more steps because I also have a fifth wheel hitch that I'll have to unbolt from the bed and frame.

Also, isn't there somewhere in there that the fuel filler tube has to be disconnected from something?

He had it in step 4. I really think if you are dealing with a hitch it will be easier to drop the tank. I did my neighbors sons 1999 Chevy in 1.5 hours with the help of 1 person. That 1.5 hours includes removing the old pump and installing a new one then reinstalling the tank. Not hard at all with the right tools. The only special tool you need is the fuel line removal tool.

By the way we got the pump assembly on Ebay for something like $165. Parts stores wanted $300 or better.

Chris

 

[Iplayfarmer]

He had it in step 4. I really think if you are dealing with a hitch it will be easier to drop the tank. I did my neighbors sons 1999 Chevy in 1.5 hours with the help of 1 person. That 1.5 hours includes removing the old pump and installing a new one then reinstalling the tank. Not hard at all with the right tools. The only special tool you need is the fuel line removal tool.

By the way we got the pump assembly on Ebay for something like $165. Parts stores wanted $300 or better.

Chris

I saw the pumps on ebay. It's hard to turn that price down.

I'm actually somewhat excited that the pump is finally going since my fuel gauge has been acting up ever since I bought the truck.

 

[workinallthetime]

Thanks for that step-by-step. Mine will have a few more steps because I also have a fifth wheel hitch that I'll have to unbolt from the bed and frame.

Also, isn't there somewhere in there that the fuel filler tube has to be disconnected from something?

step 4 is for the filler neck, if you end up droping it let me know and I will give the the run down on it that way.
One thing I dont like about droping the tank with the lines connected is you can create some pretty bad tension on the elec. terminals and possibly damage the fuel lines. the one thing you dont want to chase is a loose conection at a fuel pump, trying to determine that is not fun.
You can drop the tank slightly (4-5) inches after removing the filler tube from the tank, go in from the outside above the frame rails and disconnect the lines and connector. Sometimes the lines can give you trouble seperating, if you come to that work the lines in and out and spray a little wd-40 in the connection and they will seperate. What you are overcoming is 1 o-ring (yellow) a hard plastic spacer, and 2 or 3 metal washers in the connection.
while you have the elec. terminals open inspect the truck side for any sign of corosion or "fretting" burnt looking spots on the terminals, if so clean them up and apply dielectric greese on them. If its to bad get a new pig tail for the conection.

Anything else ya run into that gives ya trouble or ya have a question on just holler at me, I have put a few hundred of these in over the years.

 

[workinallthetime]

I saw the pumps on ebay. It's hard to turn that price down.

I'm actually somewhat excited that the pump is finally going since my fuel gauge has been acting up ever since I bought the truck.

use gm fuel treatment plus twice a year to combat this problem even with your new pump, the sulfer in the fuel eats up the contacts on the wiper surface. I dont know if any other company has a product that does that treats the fuel for this problem.

A note on your aftermarket pump, the gm will come with a life time warranty, parts only if you do it yourself, parts and labor if you have it done in the shop. BUT at about 1000.00 parts and labor if you can, do it yourself just save your paper work.

 

[FlaDon]

In my case, the whine is under the cab and from the tranny. The Allison whines in all but 5th gear. Always has, always will.

The fuel pumps are a very common source of whines and the older TBI Chevys really could be heard at idle.