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Here's an article I made of the best way I could figure out how to accomplish this professionally. Hole cut was for a 4th gen plastic tank. 3rd gen metal tanks need slight modification
Materials:
1/4" steel ring welded to the body
1/8" black anodized cover
bolts
felpro karropak gasket material
eastwood rubberized undercoating
3m seam sealer
I don't understand how so many people have fuel pump failures. I have owned 8 Fbodys over the last 26 years and have never once had a fuel pump die on me. Average time owning and driving each was about 4 years.Some were sold for something better and some were totaled. If you guys feel like you need to cut up your car to make the job easier the next time around then maybe you should reconsider where you're buying your fuel pumps from. There is no reason why a new, quality fuel pump wont last 10+ years. 90% of the members here wont even own their car that long.
I think the only reason for cutting the trap door is laziness and/or lack of tools. If your toolbox is the size of a shoebox then maybe you should reevaluate your car hobby
Yes, some of these trap door jobs are done correctly but the majority of them are hacked. Its so bad that it has been one of the first things I look for when I am in the fbody buying mood. I will walk away from any Fbody that has the trap door mod done. If the owner took the easy way out on the pump then what other areas of the car did they take short cuts on.
To the OP, your job was done a lot better than the average person does but the time spent was the same as just dropping the tank and changing the pump.
Last edited by BOTTLEDZ28; 03-01-2018 at 07:41 AM.
I don't understand how so many people have fuel pump failures. I have owned 8 Fbodys over the last 26 years and have never once had a fuel pump die on me. Average time owning and driving each was about 4 years.Some were sold for something better and some were totaled. If you guys feel like you need to cut up your car to make the job easier the next time around then maybe you should reconsider where you're buying your fuel pumps from. There is no reason why a new, quality fuel pump wont last 10+ years. 90% of the members here wont even own their car that long.
I think the only reason for cutting the trap door is laziness and/or lack of tools. If your toolbox is the size of a shoebox then maybe you should reevaluate your car hobby
Yes, some of these trap door jobs are done correctly but the majority of them are hacked. Its so bad that it has been one of the first things I look for when I am in the fbody buying mood. I will walk away from any Fbody that has the trap door mod done. If the owner took the easy way out on the pump then what other areas of the car did they take short cuts on.
To the OP, your job was done a lot better than the average person does but the time spent was the same as just dropping the tank and changing the pump.
It has nothing to do with the fuel pump source.
I work in the manufacturing sector, and can attest there is no such thing as perfect parts. People get faulty parts all the time and after dropping my fair share of tanks in fbodies, I decided it was time to change it up. I hate dropping tanks every time. The worst is a pump that dies after a few days or months making you do all the work all over again wasting hours of your time.
When I decided to go the route of the 4th gen tank swap I read about how people had fuel pump issues especially with aftermarket pumps and by sheer chance didnt want to have to take out all my powder coated parts, polished SS exhaust, freshly painted tank cover, etc etc just to drop the tank again if I had an issue. No thanks. Each time you do it wears the coating off the bolts, you inevitably scratch a part, etc.
Time wise, considering the old metal tank was already out to do the plastic tank swap, it wasnt that much extra work. And that one time I had to spend extra time is now negated since I only need 20 minutes and like 3 tools to do any modifications now.
In the end
This is quite possibly the best mod I'v ever done because it has already saved me hours of screwing around. After 50 miles on the new pump, my racetronix pump decided to die on me the day of thirdgen expo. And was unfortunately parked in a remote garage with no extensive tools, no jack. I was able to access the pump with a flat blade screw driver, hammer, and cheap socket set in 20 minutes and subsequently made it to the event. That beats having to get under the car and do all that work any day. At that time in the morning even if I had all the tools I wouldn't have had enough time to do the work and still make it to the show. But thanks to this mod I didn't get stranded and I still made it to the show.
Then after warrantying the pump, the 2nd one wouldn't hold key on engine off pressure. Bad check valve. So after 2 pumps I finally got a good one. Imagine having to drop the tank 3 times due to bad parts. Nah I'm good.
It's great you're a purist, as I am sure some are....but I'm sure many guys with the same thought process have no issues with guys minitubbing a car, welding in a roll cage, or hacking up the front end for a big turbo. But a hidden door under the carpet rustles their fee fees. Will never understand the logic there. I added a fuel access door like many factory cars have for convenience and it's far more sturdy structurally, kill me.
As far as being lazy.
Who doesn't love a good mod that makes life easier?
Oh and I found the comment about not enough tools quite funny lol
Last edited by LS2Swapped92; 03-01-2018 at 09:44 AM.
Still not a fan, but this is definitely one of the better examples of the access panel. Whom ever did my car did it with metal shears as the edges are all ragged from the various cuts.
That DSE plate is definitely one of the best doors I have seen, but IMO it is a little too thick. If you get rear-ended and it is enough to distort that sheet, the ring is likely to be ripped out of the metal instead of bending with the rest.
Since I need to fix my car eventually, I may consider putting this in since the hole is there already.
Still not a fan, but this is definitely one of the better examples of the access panel. Whom ever did my car did it with metal shears as the edges are all ragged from the various cuts.
That DSE plate is definitely one of the best doors I have seen, but IMO it is a little too thick. If you get rear-ended and it is enough to distort that sheet, the ring is likely to be ripped out of the metal instead of bending with the rest.
Since I need to fix my car eventually, I may consider putting this in since the hole is there already.
Thanks. The shitty jobs are the ones that everyone envision when they think about a trap door and thus have created the taboo. Looking to reverse that trend with a better solution.
The only thing that I wish was different is yes, the door is a bit thick, at 1/4" just for the ring, but it does still hide under the carpet well. Also it would be hard to weld in a ring that is any thinner without some sort of distortion due to heat. This is now one with the vehicle completely welded around the entire perimeter
As far as accidents go, who knows what would happen. I have subs in the trunk, some people keep tools back there, some people have rear mounted turbo setups, what happens when people get rear ended with that stuff in the back?
If the ring gets ripped out from that bad of an accident, that would be the least of my concerns, as the car is totaled at that point.
This mod has already saved me a ton of frustration and time, my hope is it will do the same for others in the future that want a similar mod without hacking their car up like a sardine can
If the ring gets ripped out from that bad of an accident, that would be the least of my concerns, as the car is totaled at that point.
Yes, but you don't want there to be an entry point for fuel to leak into the passenger compartment, that is why most cars don't have them from the factory
Yes, but you don't want there to be an entry point for fuel to leak into the passenger compartment, that is why most cars don't have them from the factory
We can sit here and speculate and be nay-sayers all day. Fact of the matter is unless you start doing some stress simulations, crash tests, etc there's no answer for how anything reacts in a crash. Sounds like cherry picking to fulfill a self-serving notion tbh.
This thread is to educate people on how to perform this mod properly and give them ideas, not sit here and whine in hindsight about hypotheticals that may not even occur
It's your life.... :shrug:
Is that your website you linked in that first post?
If safety is your absolute first concern, sell these deathtraps made in the 80s, and buy a Kia with a 5 star crash rating
While you're at it, tell Honda, GM, etc they are all risking everyone's lives.
I don't understand how so many people have fuel pump failures. I have owned 8 Fbodys over the last 26 years and have never once had a fuel pump die on me.
I don't understand how so many people have fuel pump failures.
It's the Racetronix pumps (4th gen sender). Or older pumps exposed to Ethanol.
On a side note, the fourth gen "plastic" tank has a removable neck so it can come out with the rear end still in place. If you have owned a Racetronix for any length of time this can be done in less than 20 minutes (faster than trap door). If the tank is full it will require some fuel to be sloshed out on your crotch area as you use the tank handles for removal because "I don't need any help".
For added fun, call Racetronix to order a replacement part or to tell them how amazing their product is.
After your fourth Racetronix, order the Delco MU1730 and never look back.
It's the Racetronix pumps (4th gen sender). Or older pumps exposed to Ethanol.
On a side note, the fourth gen "plastic" tank has a removable neck so it can come out with the rear end still in place. If you have owned a Racetronix for any length of time this can be done in less than 20 minutes (faster than trap door). If the tank is full it will require some fuel to be sloshed out on your crotch area as you use the tank handles for removal because "I don't need any help".
For added fun, call Racetronix to order a replacement part or to tell them how amazing their product is.
After your fourth Racetronix, order the Delco MU1730 and never look back.
is that delco pump the racetronix equivalent of the walbro 255?
Nice fab work! That is one of the best I have seen yet by far. Being a mechanic I typically do at least one fuel pump every week. It is nice when the manufacturer thought ahead and put an access panel over the tank. If my GTA was low milage and prestine having already dropped the rear once to change the pump I wouldn't do this but my car is a driver, I hammer it pretty hard and I have a 5.3 on the engine stand and turbo parts are piling up. Soon as I can afford a T56 and all the other loose ends my car will get this same mod. Thanks for posting.
is that delco pump the racetronix equivalent of the walbro 255?
Racetronix stole the Walbro 255 design and simply reversed the polarity. Walbro is a great pump, the Racetronix has extremely high failure rate. Note Walbro does not make a direct fit 255 for the Fourth Gen buckets, they should.
The Delco is it's own design. The Delco (Delphi) is a GM designed updated A/C Delco, the pumps were updated a few ways but most notably updated plastic composition that handles Ethanol better.
Delco, A/C Delco and Delphi are "different" companies but have been the same company over the years. The rumor (truth) is that they change the name to not pay labor benefits (UAW), but I digress.
I don't understand the thinking behind a properly built access door being a vapour entry risk. These cars have doors don't they? You know. Open to the atmosphere with nothing more than a rubber seal. Same thing. Build it right and there's no issue.
Really good write up. I've been following these trap door conversation with interest. My car is down to a shell and this mod just seems to make sense to me before I put it all back together . I've sold auto parts for almost 30 years and had my share of comebacks for parts right out of the box. The idea of having an easy, hidden solution to a potential problem rather than having to wrestle the tank, especially if it's thought out and done right seems like a good mod . Plus it's fun to watch the feedback it generates. Thanks for posting your work .
Ive had quality pumps fail..and factory pumps fail.Before i swapped to my ls setup and I had several motors in my previous t/a I wanted to use only gm parts back then,went through 3 or 4 pumps.After a while..dropping the tank in/out often is not something I wanted to do when I was redoing my fuel system.I made an access panel and door seal on that car,Did a wiring upgrade and wlabro 255..which also did fail after 2 yrs.
When i swapped everything to my current car and eventually boosted it.i instantly did the trap door.When i boosted the car..the 255 started to struggle and in 15 mins at the dyno I was able to swap in my current 450.
Currently Im replacing my floors and adding a cage to my car..if your worried about the stress that others have had in that area..Ive had no stress cracks/bends from the access hole I made..and this has taken a beating on the street/strip hooking up 6-700tq.
There have been too many hacks that do this mod and not enough showcasing of a job done right,which in the Op's case..Awesome job
I had to do it to mine because the previous owner cut the area above the pump and did nothing to reseal it. I believe that mine is done as close to factory as you can do it.
If I recall, the trunk area is 16 or 18 gauge metal, probably 18. I used a 16 gauge sheet cut to size with an oval cut out of the middle. Welds were gone over with seam sealer. I used nut serts on the perimeter. The nuts just barely stick out of the nut serts, are blunt tipped and are maybe 2" from the tank so I'm not worried about puncturing the gas tank. I do use weatherstrip on the perimeter of the panel as a gasket.
I've found that people who are against something like this are against it no matter how good of a job you've done simply because that wasn't how the factory intended it and any cutting is hackery.
02-28-2018, 03:22 PM
