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Fuel Pump removal and re-install how to.

132K views 111 replies 52 participants last post by  Marky Dissod 
#1 ·
In an effort to rebuild the Forum post crash, here is my contribution. A step by step how to remove and re-place a fuel pump. The maintenance was performed on a 1996 Caprice wagon. Basically all of the B/D tanks mount the same, just different filler neck and ventline location.

First off you'll want to raise the rear of the vehicle a good amount. The rear wheels of the Wagon were about 3" off the ground, this was just enough for me to use my transmission jack to keep the tank mounted on it and slide it out. You're results may vary. Safety note: chock the front wheels or put something in front to keep the car from rolling foward.

Here is the filler neck and vent line connection. There two hose clamps on the filler neck, and one on the vent line. Loosen both on the filler neck so you twist the rubber hose to help free it off the tank mount. When the tank mount end comes loose, tighten back up the other end.


These are the tank strap mount bolts, They are 13mm and a pain to get back in place. Loosen and remove the nut, but leave the bolts in place for now. Take the cross stap nut off and push the tank strap out of the way.



Now position a floor jack or transmission jack underneath the tank to support it. I used a floorjack with a peice of wood cut to fit in between the tank straps to help balance it. Put some pressure on the tank to take the load off the bolts for the straps. The bolts should come out with little effort.


Lower the tank a little bit and slide the jack towards the rear as you lower to keep the tank balanced. Remove the hose connection at the filler neck and cover up the port to prevent a fuel leak. I used two ziploc bags and safety wire. Worked pretty good, the tank tipped over and didnt get much of leak.


Now get under the car and disconnect the the retainer for the fuel suppy/return and evap lines. Its directly above the rear end.


Now I tried to cheat but it didnt work out, I tried to remove the fuelpump and sender assembly without fully dropping the tank. Don't bother you'll waste your time.


To be continued.
 
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#68 ·
Recently did a new install with the Racetronix Kit and thought I'd link it to this thread. No more messing with crappy factory wiring for me. It has some pictures and info you may find useful along with other links, like to the the Refurbish Sending Unit thread for example.

I believe it also has a link to another thread where I compare the differences between the original GM Sending unit and the Spectra replacement Sending Unit which also looks a lot like what GM now uses as a replacement SU. The Ground wire is very undersized on the replacements and should (IMHO) be modified.

http://www.impalassforum.com/vBulletin/showthread.php?t=1243034
 
#75 ·
Recently did a new install with the Racetronix Kit and thought I'd link it to this thread. No more messing with crappy factory wiring for me. It has some pictures and info you may find useful along with other links, like to the the Refurbish Sending Unit thread for example.

I believe it also has a link to another thread where I compare the differences between the original GM Sending unit and the Spectra replacement Sending Unit which also looks a lot like what GM now uses as a replacement SU. The Ground wire is very undersized on the replacements and should (IMHO) be modified.

Racetronix Kit Install - Chevy Impala SS Forum

Would this kit work on the LO3/LO5's as well? If I'm going to replace, I may as well upgrade. Looking to do this soon.
 
#70 ·
Rockauto.com says there is a pulsator for our cars. Maybe there is not..... I know the older GM cars had them to quiet down the pumps.
Since that's what RockAuto says do you have a Picture, link, anything that would help describe what you are referring to? If you look at the threads there does not seem to be any mention of it. I've been through the system completely and not sure what or where this part is that RockAuto mentions. If its on their site, it must have a part number associated with it you could provide.
 
#73 ·
Just thought I revive an old thread.

I removed my tank today and installed a new fuel pump. I read here that there are two ways recommend to drop the tank.

The first mentioned is to release the tank straps from the rear of the car, and slide the tank aft as you lower it, to clear the straps that are still hanging there from the front of the car.

The annoying thing about this method is that the straps are tight even with the tank properly supported. Getting them back on is difficult, because with them being tight, with no adjustment in the rear, the bolts are difficult to align with the two holes in the frame where they mount.

The other method is to release them from the front side, and slide the tank forward as you lower it. This is easier because you're not fighting the straps under stress because the long bolts permit you to easily release and reinstall the straps.

The PITA regarding this method is that sliding the tank forward is more difficult and you need the car to be lifted high enough to clear the differential.

I wasn't happy with rather method, so I tried something different, and I think it made the removal and replacement as easy as it gets.

First thing I did was remove the two bolts that secure the filler neck, behind the license plate.

Then I disconnected the fuel pump harness, and then the fuel supply and return lines, as well as the vent hose.

Next was to remove the exhaust shield. Then I removed the cross strap bolt from the rear of the passenger side strap. By pushing it up in the center of the tank, I was able to remove it from the bolt on the rear of the strap.

Then I rotated it over to the driver side of the car to clear the center of the tank.

I supported the tank from the center with a piece of plywood wide enough to to balance the tank, but still not cover the straps.

Then I snugged it up to the tank to support the weight.

Next I went to the rear and removed the nuts on the tank straps, but left the bolts in place. They would be difficult to remove at this point anyway, as anyone who has removed the tank by releasing these bolts only knows. Even more difficult to replace as has already been mentioned here.

So now, I go back forward and REALLY loosen the forward bolts, but leave them threaded with the straps hanging on them.

Now back to the rear strap bolts. Now, they're loose, and I can just pull the bolts out by hand.

The straps will easily rotate out of the way completely clearing the underside of the tank.

I lowered it, while rotating it sideways to allow the filler neck to clear the rear brace.

Once clear of the brace, I could drop it straight down, and roll it out from the rear.

Install simply by supporting the tank, swing the straps under the tank, reattach the rear bolts and cross strap, and tighten up the front.

Seems like all this would take longer, but I did it in half the time that it took me last time, when I worked from the rear only.

I know many here probably know this, but I didn't, so I figured it was worth posting.

I will add that a tranny jack makes this MUCH easier, because you have a wide base to support the tank, and its adjustable.

Anyway, that's it, hope it helps.
 
#74 · (Edited)
That sounds like that worked best for you. I agree removing the rear bolts is a PITA, but think it is pretty easy to just remove the 2 15mm bolts at the front and drop the strap rearward. You just have to loosen up the heat shields to get to the 2 bolts. But really, there are different ways to skin this cat, and whatever works best for you is the preferred way.

I've done this quite a few times and have used a board under the tank with a jack to support the tank. The last 2 times, I just layed on my back with my knees supporting the tank and then just manhandled it to the floor. No need to slide the tank forward under the axle. Just slid it out the side behind the rear tire.

Having the tire removed helps but even with the tire installed, there is plenty of room to bring it out the side. Did not have the car high off the ground either. Last time I did this, here is exactly how the car sat for removal. Front tires on ramps and Jack stands under the rear frame. Yes, I used 2 sets to support the rear of the car....just in case.

 
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#77 ·
Caprice Carl, the fuel pump with the kit is for an LT1, and you must substitute the TBI type fuel pump. The rest should fit.

The ground wire can be smaller than the hot lead.
 
#79 ·
Question:

My crashed wagon has a brand new fuel pump, sending unit, etc. and I would like to transfer the entire assembly to my Fleetwood. How does this affect the procedure? After dropping the tank, can I just remove the 6 nuts on top and transfer the entire assembly as one piece onto the other gas tank?
 
#80 ·
I don't believe you can do that. The Sending Unit for a Wagon is completely different from the Sedan. Just take a look at the Metal lines for the SU itself.
I thinks the FP's are the same but not the SU.
 
#82 ·
^^^^ Sending unit has different exterior lines for the wagon and sedan. Pumps for the respective LT1/LO5 units are the same. The newer style sending units will follow the bottom of the tank. The 91-93 OEM units have a fixed return line/pump mount.

If the sending unit is not broken, just replace the pump.

DO NOT BUY A BOSCH PUMP.
 
#83 ·
^^^^ Sending unit has different exterior lines for the wagon and sedan. Pumps for the respective LT1/LO5 units are the same. The newer style sending units will follow the bottom of the tank. The 91-93 OEM units have a fixed return line/pump mount.

If the sending unit is not broken, just replace the pump.

DO NOT BUY A BOSCH PUMP.
Are you certain that these differences are more than just cosmetic? I have more enthusiasm than money at the moment.



I have no idea if the sending unit in the Fleetwood works or not... the car has not been started in 10 years. What is the worst case scenario? I just want to get the car running.
 
#84 ·
If the level sensor works, and the exterior is not very rusty, the pump can be replaced. An AC Delco, Delphi, or Walbro are recommended. You can check the level sender before removing the tank. You can put a VOM across the leads, and it should read between 0 and 90 ohms. Make the car shake from front to back, or side to side, and the reading should vary slightly. You can also check the pump operation, and fuel pressure. Put a pressure gauge on the port, and jump the pump test lead to the positive post of the battery. If both work, you may not need to replace anything.

The sender from the wagon will not fit the FW. The lines on the wagon pump are much longer, and shaped differently.
 
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#85 ·
I have already verified that the pump is not engaging. The pump is completely silent and I have zero fuel pressure. I applied power to the little red jumper port, and still the pump did nothing.

I noticed that the metal tubes coming off of the Fleetwood sending unit do have surface rust. I was planning to hit them with some sandpaper and rustoleum or whatever if I end up reusing the unit. I realize that the metal tubes on the wagon unit are shaped differently, but are you SURE that it is not possible to make it work? I don't mind cutting, bending, extending rubber hoses, etc.

Just to be clear: I don't really care if my gas gauge works. I just want the car to run. Will a bad sending unit cause any other problems besides an inaccurate gas gauge?
 
#86 ·
If the rust is light, clean it up and use the original unit. The gas gauge will not affect anything else. You may get a low fuel light, and a reminder ding. If it does not have the reminder now, it is probably working. Replacing the pump is simple once you have the sender out. It takes about 15 minutes.

You will not find bending the tubing easy, it is steel. You may also break the seal at the plate. There is a channel for the hoses in the wagon body, and the FW does not have the channel. The FW has the channel for the FW, RMS and Caprice sedan sender (all the same shape, but not necessarily interchangeable). I checked my FW FSM, and the FW has separate wiring for the pump and gauge sender making it a 4 wire system. The wagon uses the same ground wire for the pump and sender, making it a 3 wire system. So, the two are not compatible electrically.

Since you have to pull the tank either way, I would just get a pump, and swap them. It is not a lot of work once the tank is down, and is less expensive by a long shot. The pump will have a connector, usually includes a new in tank harness, and there is one hose to attach. You may be required to remove the pump mount by removing a clip and spring, and the top of the pump mount. The new hose will make a loop to allow the pump mount to slide up and down on the return line.
 
#87 ·
If the rust is light, clean it up and use the original unit. The gas gauge will not affect anything else. You may get a low fuel light, and a reminder ding. If it does not have the reminder now, it is probably working. Replacing the pump is simple once you have the sender out. It takes about 15 minutes.

You will not find bending the tubing easy, it is steel. You may also break the seal at the plate. There is a channel for the hoses in the wagon body, and the FW does not have the channel. The FW has the channel for the FW, RMS and Caprice sedan sender (all the same shape, but not necessarily interchangeable). I checked my FW FSM, and the FW has separate wiring for the pump and gauge sender making it a 4 wire system. The wagon uses the same ground wire for the pump and sender, making it a 3 wire system. So, the two are not compatible electrically.

Since you have to pull the tank either way, I would just get a pump, and swap them. It is not a lot of work once the tank is down, and is less expensive by a long shot. The pump will have a connector, usually includes a new in tank harness, and there is one hose to attach. You may be required to remove the pump mount by removing a clip and spring, and the top of the pump mount. The new hose will make a loop to allow the pump mount to slide up and down on the return line.
Thank you, sir.
 
#91 ·
Hi guys,


Glad to be back, ,my mechanic diagnosed a problem with my fuel pump as shown in pictures attached. He is asking for full fuel pump assembly.


I am wondering if this one on ebay (https://ebay.to/2HjDteb) is considered full assembly and need your opinion to place the order..
 

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#92 ·
Just from the pic I don't believe that's even close to correct, and never heard of that brand used by anyone on here before. And the price is several orders out of scale with what a quality setup should run. Stick with the brand names already mentioned earlier in this thread, and be sure to replace not only the pump, but also a new harness (one with thicker wires than oem), and a new sending unit.
 
#93 ·
If the plastic pump mount is missing or broken, you need a complete sender unit.

Rock Auto has the entire unit with a pump from a number of different manufacturers. Newer pumps seem to be of poorer quality, and you might try a Walbro 255. Do NOT buy a Bosch fuel pump.
 
#94 ·
Just from the pic I don't believe that's even close to correct, and never heard of that brand used by anyone on here before. And the price is several orders out of scale with what a quality setup should run. Stick with the brand names already mentioned earlier in this thread, and be sure to replace not only the pump, but also a new harness (one with thicker wires than oem), and a new sending unit.

Thanks all for the input, i had a discussion with my mechanic and he confirmed that he needs the full sending unit as found on RockAuto and I have placed the order for one already https://www.rockauto.com/en/moreinfo.php?pk=2160454&jsn=1 :wink2:
 
#95 · (Edited)
anyone know if the 95 Buick Roadster came with an AC Delco or Delphi/Spectra fuel pump sending unit.

I like to rebuild an AC Delco but I don't want to go trough the trouble of removing one from a Roadster only to find out that's a Delphi/Spectra unit.

I removed a Delphi or Spectra from a Caprice and thought it was an aftermarket unit.
 
#96 ·
The Roadmaster came with an AC Delco unit, so if you want to have an OEM part, AC Delco is the one. The newer style sending unit has a sprung pump mount that can move to follow the bottom of the tank. The older style has a fixed pump mount that assumes the tank is a certain depth, and sets the pump where it "should be". This also may be one reason why the earlier cars tend to starve for fuel in hard turns when the fuel level is low.

The sending units are available without the pump, and most if not all of them are about equal in quality. The pump is the more important part. If you get the sending unit, and a known quality pump, you should be good to go. As above the Walbro 255 is a known good pump. Get the Spectra, or Delphi sender, and put your own Walbro pump in it.
 
#97 ·
Thanks for all the wonderful info. My pump is trying to give it up, so thought I'd put in a new complete unit, sender, harness, etc, as recommended, although the current pump only has 50K miles on it. I would like a better sending unit, though. Yes, I learned to reset that trip odometer and look at it, rather than the gas gauge! Will now visit Rock Auto and see what I want to buy. Any other comments would be welcome. I have not read all five pages of this thread, so I might be missing something, but I have definitely taken note of which parts to avoid and which are recommended! Thanks so much. V
 
#98 ·
... Any other comments would be welcome. I have not read all five pages of this thread, so I might be missing something,....
About the most perfect example of, "Asked, and answered" as I've come across. :unsure:.

There are several more threads on the least painful method(s) of tank removal, replacement of parts and re-installing the tank that are 'must reads'. Several of us (yes, me included) have been guilty of an easily overlooked or easily incorrectly done step to have had to tear everything down again after a month or two of a new installation. Don't be that guy.
 
#100 ·
I just felt like adding this quote from my build thread:

Just a few notes...

There has been a lot of discussion over the years about the best way to go about R&Ring the fuel pump. Some folks have even elected to cut an access hole in the trunk floor. Now that I've fooled around with more than one gas tank, I feel like I have a pretty good understanding of the best way to do it. There is no need to cut an access hole. The job is no big deal once you understand how everything goes together. My method goes something like this:
  • Jack up the rear of the car as high as you are safely and comfortably able. Remove one of the rear wheels.
  • Disconnect the straps at the rear (closest to the rear bumper). Lower tank. Disconnect lines.
  • Disconnect straps at the front, completely removing them from the car.
  • R&R pump, sender, etc.
  • Reconnect straps at the rear first. Slide tank into position. Connect lines.
  • Get underneath the tank, on your back, with your head towards the front of the car, and your feet sticking out the rear.
  • Wrestle tank and straps into position. Start front strap bolts by hand, then tighten with socket.
  • Connect filler neck hose, vent hose, and wiring harness.
  • Put wheel back on. Lower car. Fill tank.
People always debate whether you should disconnect the straps at the front or the rear, but the truth is you will make the job 10x easier if you do it in this order and remove the straps.

Also, some may have noticed that I abandoned the Frankenstein sender I was playing with earlier in the thread. The bottom line is that this has just become a much more thorough build than originally planned.

One more thing for you Fleetwood guys: If your trunk pulldown doesn't work, you need Delco part number 16629927. It's cheap on Rock Auto, and fixes the problem instantly. R&R involves 1 screw.
 
#102 ·
I'm from the 'undo front of straps' school. The filler neck comes away clean, the lines are easier to access coming down and going up, leaving one side fixed (the rear in this case) acts as a centering and fore/aft guide, and there's no need to line up a bolt across a hole - simply loose-start the adjusters and run them home tight. The only time I might try the 'remove both ends' or just the rear bolts might be if I don't have a floorjack.

Good list you made on the sequence though. But while it may seem so obvious it "goes without saying", the first bullet needs to add to use good quality jackstands before starting anything else. There was just a clip on a news show some 'young dad' got under his car with just the scissor jack from his trunk and it collapsed leaving him about dead until firemen lifted the car off of him.
 
#101 ·
Thank you! It's been so hot here that I haven't even jacked up the car yet. I have dropped 3 fuel tanks in 3 different vehicles, so I have some experience. At least I don't have to dismantle the suspension to get to this one. I have seen it recommended to remove the heat shields. I hope to investigate tomorrow. Unfortunately I have more than this project to deal with...but this forum is a life saver.
 
#103 · (Edited by Moderator)
These are specific notes on my 95 Caprice wagon, from the 103 pound, 68 yr old woman who did it. Yes, a good floor jack and good jack stands help a lot. Also, WEAR YOUR SAFETY GOGGLES.

  1. Remove heat shields.
  2. I could tell that my "professional mechanic" (meaning the shop I trusted and paid money to) disconnected the fuel filler and vent from the fuel orifice. But, I did not have the ability to maneuver that he did, and I had to remove the hoses from the tank proper.
  3. It's obvious that the straps are meant to be removed from the "front". And same mechanic had actually used anti-seize on the bolts! It looks like the rear bolts have never been touched, but who cares? They could easily be cut and replaced if they turn out to be as ugly as they look.
  4. Remind newbies like me that you need to slide the rubber "boots" off the fuel line connectors before using the QD tool. And, the cheapo Harbor Freight tool worked fine. Also, realize that there will be a little gasoline gush when you pull the lines apart.
  5. The wiring disconnects back by the rear bumper, NOT at the tank.
  6. If you remove a wheel, it is easy to slide the tank out from under the side of the car.
  7. Getting the tank back in will be a challenge, and if I come up with anything that I like, I will post.

All of the info already here has been invaluable. Thank you! Also, forgot to add, that the liquid courage of beer is good, but of course not too much. One needs to reserve the harder stuff for after the job! LOL.
 
#106 ·
Also, the original "how to" DOES tell you to remove the fuel connection "boots". I had to look at my printout again, and saw that. Still waiting on the new pump. I paid extra to get it here (from California to Eastern Oregon) last Thursday, now it's supposed to arrive today. Am interested in what kind of fun it's going to be, reinstalling the tank.
 
#107 · (Edited by Moderator)
Job done, car started, no leaks!

As with any first-time jobs, it is a booger. And as a 103-pound woman, I absolutely could not ask for help. I have my pride! Getting under the tank with your legs does afford you the best leverage and maneuverability. The f**king filler hose was actually the most obnoxious part of the journey. Thinking back, this is my 4th fuel tank drop and my 3rd in-tank pump. Glad I just bought a completely new assembly, and dropped right in, voila!

After a bit of cranking to fill the lines, she fired right up. I can hear this pump working in the tank. I got a Delphi from RockAuto. If it hadn't been for this forum I would have never dared tackle this job. Thanks so much! I love you all! Course this forum is what also empowered me to remove and clean my optispark and replace the seals...again, y'all are real-life savers! I love my wagon and long may she drive!
 
#108 ·
Job done, car started, no leaks! As with any first time jobs, it is a booger. And as a 103 pound woman, I absolutely could not ask for help. I have my pride! Getting under the tank with your legs does afford you the best leverage and maneuverability. The f**king filler hose was actually the most obnoxious part of the journey. Thinking back, this is my 4th fuel tank drop, and my 3rd in-tank pump. Glad I just bought a complete new assembly, dropped right in, voila! After a bit of cranking to fill the lines, she fired right up. I can hear this pump working in the tank. I got a Delphi from RockAuto. If it hadn''t been for this forum I would have never dared tackle this job. Thanks so much! I love you all! Course this forum is what also empowered me to remove and clean my optispark and replace the seals...again, y'all are real life savers! I love my wagon and long may she drive!
Hello, from a 73 yr old man, I have got to admire you for doing this work. I have always done my mechanical work because of seeing too much sorry and expensive work the shops do, and being such a perfectionist. Always glad to see a woman jump in and tackle working on vehicles, so keep up the good work and drive the wheels off that wagon. Best wishes from an owner of a 20,000 mile 1996 Impala SS and a life long hotrodder until the day I die.
 
#110 ·
A bit of useful information that most will probably already know. In older vehicles (2007 and earlier) fuel system components don't like ethanol, and is now at least 10% added to gasoline. These older fuel systems will ALL corrode over time and the best way to help prevent this is to add an ethanol corrosion treatment, such as Sta-bil to each fill up. I use the marine grade and also add a product called Archoil fuel treatment. This combination has served me well as I have two older vehicles with no fuel system related problems since using these products. Just wanted to pass this along after hearing several people talking about corrosion around the in-tank fuel pump.
 
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