thomp62301 Posted April 22, 2010 Report Share Posted April 22, 2010 This is my How-To on installing a Walbro 255LHP fuel pump on my 2003 Silverado SS with the return style fuel system. If theres anything you feel I need to add or change, feel free to chime in. First I dropped the fuel tank by removing the 3 hoses and 2 electrical connections. Followed by the 2 straps holding the tank in place. Just make sure you have ran the tank low so your not bench pressing 20+ gallons of fuel. I ran the truck till the low fuel light was on and was able to drop it and lift it back up fairly easily. You can also remove the bed if you prefer to avoid the above. It just will take a few friends and maybe even a few beers to get it off. With the tank out, I used a large screwdriver and a hammer to remove the retaining ring. Then remove the pump assembly. Next, dissemble the pump assembly completely and with a die grinder, I ground the bottom of the pump housing smooth so the new pump would fit in place. I also had to do a little grinding to the underside so the new sock would slide onto the bottom. I then installed the new pump into the cage. The pump fit fairly snug, but I did drill two holes and secured the pump just for some more piece of mind. The kit I used was from Magna Charger for the 04-up silversado’s with the non return fuel system so the hose supplied in the kit was not long enough. So I used some high pressure fuel line and clamps. You will then have to cut the electrical connector off the harness and crimp on 2 push on style connectors to plug into the new pump. Final product Final step is to reassemble the pump assembly and reinstall into the tank. You can now rest assure you have plenty of fuel for your future mods. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted April 22, 2010 Report Share Posted April 22, 2010 Nice write up brother! Quote Link to comment Share on other sites More sharing options...
8 UR HMI Posted April 22, 2010 Report Share Posted April 22, 2010 yea im thinking about redoing my wiring cause its just butt capped in the middle. i couldnt find a way to solder it but i think i know how i can do it. Quote Link to comment Share on other sites More sharing options...
joeyg Posted June 14, 2010 Report Share Posted June 14, 2010 Yeah, this looks similar to how I did mine, but unfortunately, if I get below 3/4 tank and boost kicks in, fuel sloshes to the rear and the pump doesn't pump. It's a pretty big PITA. It's only for WOT, but I like WOT, especially for ppl that need a power check. Really is a nice write up tho man! Quote Link to comment Share on other sites More sharing options...
thomp62301 Posted June 14, 2010 Author Report Share Posted June 14, 2010 Yeah, this looks similar to how I did mine, but unfortunately, if I get below 3/4 tank and boost kicks in, fuel sloshes to the rear and the pump doesn't pump. It's a pretty big PITA. It's only for WOT, but I like WOT, especially for ppl that need a power check. Really is a nice write up tho man! huh... I havn't ran into that problem. I havn't sprayed it with a big shot since I installed the pump. Maybe problems will surface when I get back up to the 150 jets. Quote Link to comment Share on other sites More sharing options...
smalltownguy Posted August 2, 2010 Report Share Posted August 2, 2010 How bad was it dropping the tank to do this? Do i need a friend around for this? And I don't have many mods just headers intake tune really so yal know a good replacement pump for me? Thanks good write up! Quote Link to comment Share on other sites More sharing options...
8 UR HMI Posted August 3, 2010 Report Share Posted August 3, 2010 (edited) How bad was it dropping the tank to do this? Do i need a friend around for this? And I don't have many mods just headers intake tune really so yal know a good replacement pump for me? Thanks good write up! make sure the tank is pretty close to empty, loosen the bolts that the hangers are attached to, disconnect all the hoses, disconnect the FILL NECK get a board under the tanke and use a jack to lower it down then its simple as pie from there. a friend isnt necessary but it couldnt hurt. Edited August 3, 2010 by 8 UR HMI (see edit history) Quote Link to comment Share on other sites More sharing options...
silverado_ss_04 Posted November 8, 2010 Report Share Posted November 8, 2010 im doing this very soon, Thanks for the info Quote Link to comment Share on other sites More sharing options...
thomp62301 Posted November 8, 2010 Author Report Share Posted November 8, 2010 im doing this very soon, Thanks for the info By the Walbro pump kit from magnacharger. since you have an 04, it will basically be a direct bolt in. Quote Link to comment Share on other sites More sharing options...
silverado_ss_04 Posted November 8, 2010 Report Share Posted November 8, 2010 By the Walbro pump kit from magnacharger. since you have an 04, it will basically be a direct bolt in. I already have the pump, not the kit. looks like i will just need to make the pump fit in the housing and get some fuel line? Quote Link to comment Share on other sites More sharing options...
thomp62301 Posted November 9, 2010 Author Report Share Posted November 9, 2010 I already have the pump, not the kit. looks like i will just need to make the pump fit in the housing and get some fuel line? High pressure fuel line, clamps, and some wiring, you should be set. Quote Link to comment Share on other sites More sharing options...
shawnss Posted November 9, 2010 Report Share Posted November 9, 2010 so did you ever have any problems when you went WOT on spray? just wondering cause i might be doing twin walbros after my tranny swap. Quote Link to comment Share on other sites More sharing options...
thomp62301 Posted November 10, 2010 Author Report Share Posted November 10, 2010 (edited) so did you ever have any problems when you went WOT on spray? just wondering cause i might be doing twin walbros after my tranny swap. I was making some passes on the highway a few weeks back on 100 then 150 shot. No problems what so ever. My edge insite moniter I use for my diesel had it deep in the 11's in 1/4 mi passes. I just wonder how accurate it is. Edit: At the time the tank was 1/2 full. That may make a difference. Edited November 10, 2010 by thomp62301 (see edit history) Quote Link to comment Share on other sites More sharing options...
rob777 Posted December 7, 2013 Report Share Posted December 7, 2013 I did the walbro, works great. Had too pull it out, truck started sputtering. Found out high pressure fuel injection hose does not last. Went to Carquest and purchased high pressure submersible fuel injection hose, about 20 bucks. Three years no more problems. I also drilled some extra holes in the bottom of the plastic fuel pump assembly and a good slit that the fuel sock actually sticks out the side so it would not starve for gas under boost. Quote Link to comment Share on other sites More sharing options...
Downeast Johnny Posted December 8, 2013 Report Share Posted December 8, 2013 I did the walbro, works great. Had too pull it out, truck started sputtering. Found out high pressure fuel injection hose does not last. Went to Carquest and purchased high pressure submersible fuel injection hose, about 20 bucks. Three years no more problems. I also drilled some extra holes in the bottom of the plastic fuel pump assembly and a good slit that the fuel sock actually sticks out the side so it would not starve for gas under boost. Thanks for the tips man. Quote Link to comment Share on other sites More sharing options...
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