Replacing Fuel Pump.. Drop Tank or Remove Bed?

Before you go replacing the pump, check the ground to make sure it's not rusted, causing an open circuit.

Group: alt.autos.4x4.chevy-trucks Date: Sun, Apr 2, 2006, 10:10am (EDT+4) From: red snipped-for-privacy@sbcglobal.net (JQ) =A0=A0=A0=A0Truck is a 1990 Chevy k1500, 160k miles. I'm getting battery voltage to the grey wire on the fuel pump harness, but no fuel pressure/pump activity. I'm getting ready to drop the tank and check/or replace the fuel pump unit, but am wondering if it'd be easier to get a few friends to help me remove the bed and access the pump from above. =A0=A0=A0=A0It's a short-bed Stepside model, I was told it was a fiberglass bed but I think the only fiberglass is the rear fenders. =A0=A0=A0=A0Anybody with experience or suggestions before I drop the tank? Thanks for any info.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% "Sometimes, when you're up to your butt in alligators, it's hard to remember that the intial objective was to drain the swamp." ~ Unknown ~

friends

Make sure that the ground is good before you replace the pump. It is usually a short line from the pump to the frame, they rust and go bad. As for working on it. pulling the bed is MUCH easier, you don't have to fight with the filler neck or the rusty tank straps. Plus since the pump is in the top of the tank it means you don't have to fight with the gas in the tank like you do when you drop the tank. I also suggest that while you have the bed off, take the chassis to a car wash and clean it VERY well and throw a coat of chassis paint on it. Also doesn't hurt to spray the tank and brake/fuel lines to stop them from rusting as well.

Thanks for the replies, I've checked the ground to the frame, sanded the frame to clean metal, cleaned the bolt and ground wire, still no difference.

The very last time it started up was ugly, the truck would rev to about

1500 rpms, then sputter down to about 200 rpms, rev, sputter, for about 30 seconds. It finally stalled and never started up again. I've got a new fuel filter, and checked everything else possible. I use Techron Fuel Injection Cleaner every tune up, and always buy good gas.

I do usually let the fuel level fall to near empty before fueling up. Maybe I'll reconsider that with this new pump kit, it comes with a warning not to let it fall below 1/3 of a tank regularly.

I've got my transmission jack setup to cradle the tank but at its lowest level I think I'm gonna have some clearance problems pulling the tank out from under the truck. Before I go any further I'm gonna see what exactly I need to do to raise the bed up. If it's straight forward I might go that route.

I live in a dry climate so rust isn't much of a concern, the underside is pretty clean. But my next step after replacing the fuel pump is to get the truck painted so I might do just that anyways.

Get a short 2X4 and smack the bottom of the tank. If the pump starts, it's most likely bad. At 160K miles if it's the original pump it's past it time.

Ask about suggestions for a replacement pump.

Al

Had to do this on my 90 stepside a year or so ago. Be very careful with the fuel lines on the sending unit. I ended up having to put in a new sending unit because one turn of the wrench and they were history. If you plan on keeping it a while, maybe think about replacing the sending unit too. I found the best price at

. In my case, I opted for pulling the whole box off. Made everything much easier and also needed the room to access the cab corners for replacement.

I ended up getting a kit from NAPA, new fuel pump/sending unit/harness/strainer. I have some buddies coming over to help me with the bed, but I'm not sure how to go about it (I won't see the truck until tomorrow). I have an LMC catalog that shows an exploded view of the stepside bed, but I can't figure out if I can remove the bed as a whole or if it has to come apart separately (aka removing fenders first, then floor panel, etc.) Thanks for any info.

Unplug the wiring and remove the bolts through the mounts and lift the box off in one piece.

on my 92 K1500....

removed spare tire, removed trailer hitch, disconnected rear lights wiring harness, removed screws at gas tank fill and disconnected gas tank fill ground strap. Good idea to disconnect battery before you do anything. Then removed the 6 bolts ( I think its 6 ) that hold the bed down to the frame. You are then ready to lift bed off frame. You need at least 4 people to move the bed around. I would suggest sitting bed on the ground or on some saw horses... You then have full access to the gas tank top where you can disconnect the fuel lines and remove the fuel pump sending unit. Pay careful attention to how the fuel pump is installed. I just replaced the fuel pump when I did mine, but looking back on it I should have went on an replaced the entire assembly. The fuel pump assembly is secured to the fuel tank by a type of "lock ring" You move it one way to tighten and the other way to loosen, you should be able to see this, and it fairly obvious. Always remember you are working on a gas tank! that contains gas and be very careful about potential sparks or flame.....

----------- Elbert snipped-for-privacy@me.com

Glad I took the bed off because the fuel lines on the sending unit were pretty corroded and hard to disconnect. Plus the lock ring was fused to the pump and wouldn't move independently. After a few hours of penetrating fluid and tapping, it finally separated. Put the new fuel pump unit in and it runs great. It was 8 bolts to remove the bed, plus removing the fuel filler ground strap and rear tail light wiring. I took the frame advice and cleaned up and sprayed the frame/chassis with 3 cans of "underbody coating"... looks a lot better and hopefully lasts a bit. I'll probably hit the underside of the doors and fenders soon. Removing the bed was best with

4 people, wasn't exactly heavy but with any less it was akward to move around. Next step is paint job and cab interior restoration. Thanks for the info.