1987 V20 fuel pump

[Troyport]

Time for a fuel pump. Consensus is removing the bed is the way to go, but my sending unit / pump assembly is about 40% under the cab, will I have enough room to wiggle it out? Or do I have to drop the tank instead? If I drop the tank, I can't see any way to remove the lines on top. I'm thinking I have to move the bed to get to the lines, then drop the tank at least some to get the unit out. Or am I overthinking this whole thing. Thanks.

 

[Ricko1966]

I drop the tank. When you go under to drop the tank,take pruning shears with you. Move the tank enough to reach up and cut the lines. I bring them down filler neck tank brackets,everything in one shot. Use new hose going back on. Pre install new lines with clamps in place on the tank,leave your lines long,cut as needed.

 

[Broken85]

I drop the tank. When you go under to drop the tank,take pruning shears with you. Move the tank enough to reach up and cut the lines. I bring them down filler neck tank brackets,everything in one shot. Use new hose going back on. Pre install new lines with clamps in place on the tank,leave your lines long,cut as needed.

This is the way to do it. Even if you remove the bed, you can’t get the sending unit out. 4 bolts on each tank bracket and also disconnect the fill spout from the bed and it drops straight down. 12” of extra house when you reinstall about right. If the tank is empty, you can’t push it up with one hand and get a bolt in there.

When the tank mounts are down, weld your nuts to the back of the bracket if they are not already done. Some had them welded and some you had to reach behind with a wrench. If you need to put a wrench on the back, you are going to be cussing. Making sure the nuts are captured on the mount is like 90% of the reinstall.

 

[Ricko1966]

Don't forget to undo the tank ground from the frame. And I'm sure broken85 meant you can push the tank up with 1 hand and start a bolt,that's how I do them . They are actual to easy to drop and reinstall compared to so many other tanks.

 

[Troyport]

Thanks for the replies. Just so I am sure, reinstall with an extra 12" of hose, that way I can reconnect with the tank lower so I have room to work. Any trick so when the tank is pushed up I don't kink the extra hose? And what about the wires? Thanks again.

 

[Ricko1966]

Thanks for the replies. Just so I am sure, reinstall with an extra 12" of hose, that way I can reconnect with the tank lower so I have room to work. Any trick so when the tank is pushed up I don't kink the extra hose? And what about the wires? Thanks again.

I just put on extra hose and cut it to a workable length as I push it up. Never measured it,it won't kink if you route it so it doesn't kink. The wires 1 unscrew off of the frame the others unplug about 2 foot from the sending unit. I put the tank side hose clamps on tight and have another clamp on each hose loose so I can slide it up the hose to where it needs to be. Use a nut driver on the clamps. A 6 in 1 screwdriver with the bit pulled out works great.

 

[Troyport]

Thanks!

 

[Broken85]

Thanks for the replies. Just so I am sure, reinstall with an extra 12" of hose, that way I can reconnect with the tank lower so I have room to work. Any trick so when the tank is pushed up I don't kink the extra hose? And what about the wires? Thanks again.

You will need 3/8 fuel line for the supply, 5/16 for the return and 1/4 for the vent. If your hose comes off a roll (which they all do), the natural bend in the tube makes it curl up right on top of the tank nicely as you push it up.

Just keep the natural arc in mind as you attach both ends of the hose and it will curl up like a spring when you jack it up. You can extend the wires if you need to as well. Don’t worry about snipping it at the sending unit it there isn’t enough slack on the way down, easy to fix.

 

[Ricko1966]

The sending unit has a connector it unhooks easily,follow the wires from the sender to the connector. I would seriously discourage you from cutting the sending wires, just remember to disconnect them at the start. On an 87 those wires don't just work the gauge they are also power and ground for your fuel pump. A cut and spliced wire is one more potential failure point in the future.

 

[Troyport]

Thanks all for the input. Pump still moves fuel, but can only produce 4psi. Of course my tank was full, so last night, since the TB is already off for a rebuild, I hooked rubber fuel line to the solid line on top of the engine, and the other end into the filler neck of my '68 GMC, put power to the pigtail at the relay, sat back and waited for the tank to be dry. Took a while!

 

[Troyport]

Figured I would update: as always, I was overthinking it. I just looped the extra fuel hose in a circle the way it wanted to go due to the curve off the spool, plenty of room to work. Rebuilt the TB and also found a crack in the EGR gasket that was allowing a constant small trickle of exhaust to always enter the intake. With all this done, holy crap did the truck wake up! Thanks for all the advice.

 

[AuroraGirl]

Don't forget to undo the tank ground from the frame. And I'm sure broken85 meant you can push the tank up with 1 hand and start a bolt,that's how I do them . They are actual to easy to drop and reinstall compared to so many other tanks.

doesnt the ground go through a hole in the frame and then mount, and then uses a spade tab on the sender? if so id advise removing the sender spade and then removing the ground after so you dont eat more rust dust and one doesnt yank the wire if it doesnt come out the frame opening nicely

 

[AuroraGirl]

A new fuel pump in the tank should have a special length of aspirator hose that runs from the pump to the top of the sending unit, factory hose didnt hold up well even in the 90s and aftermarket companies often put non submerge fuel line on them, they then swell and suck air

Also make sure your tank is baffled, that helps