Install easy access door for fuel pump

Having owned these style wagons and Caprices for 17 years, like alot of us, I have had to drop the gas tanks to replace the fuel pump.  Never fails, the tank is usually closer to full than empty and they usually don't fail in your driveway.  They will leave you stranded.  Joel, is correct, they are dependable and last a long time; but they fail, it's just a matter of time.  The two that I replaced one lasted 164K and the other 215K.  One stranded me 150 miles from home late at night.

With the rash of fuel pump failures that we have seen, Krzdimond(Robert), Roo and just in the last couple of days COL, I knew the writing was on the wall with my RMW with 157K.  If I were Roo's age (and I wish I was), or even Robert's, I wouldn't mind changing the pump.  But I'm not and the days of me changing another fuel pump are over, the COL will back me on that I'm sure.

I know Impala guys have cut trap doors to access the fuel pump; but I haven't seen anyone do it to a wagon.  I had the time.  I also had an extra sending unit, as the tubing from the sending unit has various offset bends.  I got out the extra sending unit and got an idea where to cut.  VERY IMPORTANT:  DROP THE FUEL TANK DOWN AN INCH, FOR SAFETY.  I used a dremel with a small cutting wheel.  Obviously, you need to pull out the 3rd seat and peel back the rug.  I laid the sending where I thought it would go.  I then cut a 1" x 1" hole to see where I was.



Bingo, I hit it perfectly, although it is obvious, by the raised area that the sending unit should be there.  I then lined up the sending unit on top of the floor to get an idea on the path that it follows.  I marked the path on the floor and started cutting.


I took the piece that I cut out and traced it to make a copy.  I then added a 1/2 inch all the way around and made a cardboard pattern.  I brought the pattern along with the piece of metal that was cut out.  I had then cut out the pattern with the same thickness sheet metal and replicate the bends.





I Fluid Filmed (undercoating) the sending unit.  



I then put wiring jackets and tie wrapped the tubing to keep it secure.



I drilled the cover for screws.  There is one section that is too close to the tank, that you cannot use screws.



I used a small bead of silicon caulking, as it was a good fit.



I screwed the cover on, and there's the finished product.



I figured I turned a 4 to 5 hour job into a 45 minute job (just have to remember to carry an extra fuel pump).

I have the pattern if anyone wants a copy.  All and all, not a bad job; with my luck the fuel pump will never have a problem.  With the new access door, everything can be done without getting underneath the wagon.


Tom

This is an excellent idea for anyone who takes their car on road trips.

I love it when i see folks unafraid to cut up their cars for mods,.

would a larger hole make things much easier?
it could be the picture angle,.

only difference i would do would be some urethane tape sticky on the one side



Good idea tom,.

Nick

Nick

That is absolutely true. I had two sided tape, and I didn't feel like going to auto supply again, but I should have.

Tom

Yeeeah... I can now see the value in this hole's location.


*adds to to-do list*

nice.

Pretty cool, Tom.

Great idea Tom. Not sure why GM did not do this, it makes so much sense. Was is difficult to get to the hose ends to disconnect? Not familiar with the urethane tape. Where would you use it?

BigBlackBeaSSt wrote:

Not familiar with the urethane tape. Where would you use it?

You see where he made a border of the silicone?
just make a border of the urethane tape,.to use as a gasket, to keep the elments out,. if its sticky on one side, it makes for easy on off

Original design of vehicles never promotes easy repairs,. just easy assembly.

I could see some nice nuts welded on the bottom side with studs sticking up.
but that would involve dropping the tank,..

Nick

gotta be careful with the cutting wheel sparks too, especially on an old tank that might have rotten lines,.

Nice work Tom, a must on my wagons.

phantom 309 wrote:

would a larger hole make things much easier?
it could be the picture angle,.

Actually Nick, the hole is plenty big enough, to get at the nuts and pull the pump. I see what your talking about, but it's just the angle of the picture. The circular ring will come straight up. On the connection end, it is big as it can be, because of the seat belt bolt, but there is plenty of room to disconnect.

BigBlackBeaSSt wrote:

Was is difficult to get to the hose ends to disconnect?

I didn't have any reason to disconnect, but there is plenty of room.

phantom 309 wrote:

gotta be careful with the cutting wheel sparks too, especially on an old tank that might have rotten lines,.

Very good advice, I came dangerously close. That's why I have in the instructions, drop the tank 1 inch.


Thanks Bill, Jason and Dave for the compliments.

It's really pretty easy, I did it!

I will make up some patterns at Staples in the next week or so. If anyone wants one, just ask.


Tom

Awesome idea Tom and I would like one as well to go with other goodies.Is there any differences between the TBI and LT-1 fuel pump and lines?

Flasheroo wrote:

Awesome idea Tom and I would like one as well to go with other goodies.Is there any differences between the TBI and LT-1 fuel pump and lines?

I'll get you one Jim, it will be a few weeks.

It might be the same shape as a TBI. I don't know for sure, maybe Fred K might know.

Tom

The template will be the same for all years. Nice work Tom, I had thought about this in the past, but never went any further. I'd be interested in a template

Sprocket wrote:

The template will be the same for all years. Nice work Tom, I had thought about this in the past, but never went any further. I'd be interested in a template

I'll have them ready in a week or two. I'll get your address then, Jon.

Tom

Smart mod! I would have killed to have had a trap door on the Denali when I did that pump!

Tom, could you bring one of those templates to WFNY?

Did you make the opening large enough to get to all 6 bolts around the ring? Also, is there enough room to get the fuel line removal tool into the fittings?

The only issue I see here is the wire harness. Mine was pinched between the floor and the tank.

Have you done a test R&R on this yet? Or did you just cut the hole?

Great idea Tom. You have just assured you will never have a fuel pump problem again.
Dick

The nice thing is that the the B-body fuel pump is about the size of your fist and can easily fit next to your spare ignition coil / ignition control module assembly and coil wire, which every LT1 owner should keep in the storage compartment...

sherlock9c1 wrote:

The nice thing is that the the B-body fuel pump is about the size of your fist and can easily fit next to your spare ignition coil / ignition control module assembly and coil wire, which every LT1 owner should keep in the storage compartment...

Along with the spare coolant tee and flow restricter

sherlock9c1 wrote:

Tom, could you bring one of those templates to WFNY?

Did you make the opening large enough to get to all 6 bolts around the ring? Also, is there enough room to get the fuel line removal tool into the fittings?

I will bring some to WF, there is plenty of room that 6 bolt ring will come straight up and there is more than enough room on the connection end.

Superior Finish wrote:

The only issue I see here is the wire harness. Mine was pinched between the floor and the tank.

Have you done a test R&R on this yet? Or did you just cut the hole?

If the wire is pinched just loosen the tank and drop it an inch, real easy. I have not R & R'd it but it will easily come right out, probably will have to pull a little slack on the wire.

COL wrote:

Great idea Tom. You have just assured you will never have a fuel pump problem again.
Dick

That is true Dick, but I am not driving that wagon this summer, as I am going through it, fixing, upgrading and repairing. So, I will be doing the Caprice Wagon next week.


Next to taking off the rear shocks, dropping the tank and replacing the fuel pump is the worst job. No more for me. Today, I am going down to the sheet metal shop to have them make me another cover for the Caprice Wagon. Then sometime, I will figure out the Fleetwood.

Tom

95BRMW wrote:

sherlock9c1 wrote:

The nice thing is that the the B-body fuel pump is about the size of your fist and can easily fit next to your spare ignition coil / ignition control module assembly and coil wire, which every LT1 owner should keep in the storage compartment...

Along with the spare coolant tee and flow restricter

Now to figure out how to carry an extra transmission around. Ha Ha

silverfox103 wrote:

Now to figure out how to carry an extra transmission around. Ha Ha

switch to 4l80e,.they are better suited for such a heavy vehicle, and can handle the LT 1's torque much better,.

problem solved,.

nick

The pumps differ from TBI to the LT's (or TPI in my case) but the sending units and hoses are alike. So one pattern would work for all our vehicles regardless of engines or year of production.

Great mod...Nice assist Nick with the tape idea.

silverfox103 wrote:

Next to taking off the rear shocks, dropping the tank and replacing the fuel pump is the worst job. No more for me. Today, I am going down to the sheet metal shop to have them make me another cover for the Caprice Wagon. Then sometime, I will figure out the Fleetwood.

Tom

Really? I've already done the two worst jobs on the car? Cool.

I replaced the fuel pump last summer, and I'm hoping that it will be a long time before I have to do it again. If I do, I might go your route. On my Saab, all I have to do is to roll back the carpet. That make so much more sense.

If anyone wants a Pattern of the cut piece and the cover piece, send me your email address.

Tom

Sent to Shawn, Mike, Mike, and Joel.  Any problems let me know, as they are large files.

Tom

Did a fuel pump in a wagon this wekend. Not too hard. The hardest part was getting the filler hose off the tank. Used pb blaster and a pry bar.

Tom, give this a shot.

Now there's an idea!  I'll get back to you on that.

Tom

So to answer the question of "Why didn't they think to do this" - I feel somewhat qualified to offer an answer. I worked in the fuel pump/fuel handling design center of Delphi for about 6 years.

Here's how it works. GM designs the car, but farms out the fuel handling work to an outside company like Delphi. Delphi then owns the fuel system, and along with it they also own the costs of warranty work related to it. 

You guys wouldn't imagine the astronomical costs to add a "non value added" feature like a fuel sending unit access door to a body that doesn't already have it, and since GM doesn't own the cost responsibility of warranty work, they have ZERO incentive to create that cost for themselves. And at the point when they warranty runs out, the repair costs are still not their problem or financial responsibility.

Having also worked in body design, trust me - those guys are plenty smart enough to think of it but they can't predict what the fuel system requirements will be because all of the fuel handling "works" is designed around the area of the body they are given from "god", including the tank.  The fuel handling designers are also darn sure smart enough to want it, but body design isn't negotiable. Poop flows down hill and suppliers are at the bottom - they take what they are given and like it - "or else".

On the cars where you see access panels designed in - you'd probably learn that the parent company was responsible for at least some part of the warranty or replacement costs for those components.

Features like that don't appear because one company is smarter than another, or because they are more user/mechanic friendly. They appear for one reason only, ever, and that's because some pencil pushing nerd calculized that at some point it would save them a LOT of money to do so. Period.

Hope that helps answer the age old quandry of "why didn't they think of that" from a guy who worked in groups that thought of it every day.

Peace,
J

Just as I had always suspected!!!!

As with the Pinto, the bean counters figured that it was more cost effective to pay off the death benefits, than it was to "fix" the cars..... and it WAS, until the media got wind of it.....

Good info John.

silverfox103 wrote:

Sent to Shawn, Mike, Mike, and Joel.  Any problems let me know, as they are large files.

Tom

Tom, I got the files no problem. Thanks for the share.

Tom, What a great idea you came up with on easy removal of fuel pump! I'm new to the forum and I have two long roofs a 1992 OCC and a 1994 RMW, and I'm sure in the near future I will need to R&R my fuel pump on one of my wagons. I would sure appreciate a copy of the pattern for the cut and the cover. I live in Tucson Az and there are quite a few rust free long roofs in this area. Really enjoy the forum!  Here is my email address: novajoe67@hotmail.com Many thanks Joe Allen

Hi Joe

I'm on the way out the door, I will email you the info either tonight or tomorrow. We lived in Tucson for a short time in @ 1979 - 1980., loved it.

Tom

Email sent to silverfox103 for a template, thanks!

I'm trying to decide if I want to go ahead and do this now and be ready if and when I have to replace the pump, or wait and do it when the time comes.

I did this to a 94 Camaro we had years ago, because you have to drop the exhaust and rear end to get the fuel tank out. Far easier to cut a hole and then cut out a patch from an old hood to cover it up. Car was kinda a junker anyways. I can't see doing this to a car I care about like my Olds, or even the 92 Caprice I just got. Only thing that made it difficult getting the tank in and out was the fact it was 3/4 full, and the sender lines didn't want to disconnect.

I'd also say for any wagons in northern climates, cutting this hole is probably more worth it for rustproofing the sender lines and fuel line fittings than anything else. if you can prevent the sender lines from rubbing on the body, and keep them fully coated in oil/grease/whathaveyou, they will last forever. I rustproofed my last wagon's fuel system (paint baked/cured, then oi) and then drove it through 8 upstate NY winters. It finally rusted through shortly thereafter and I had to put new metal ends on the fuel lines and that was NOT fun.

That sounds like a lot of work when you could just buy a readily available sending unit and not cut up the car to me.

What kind of mileage are you getting out of a fuel pump that makes this worth it?

RedandBlack wrote:

That sounds like a lot of work when you could just buy a readily available sending unit and not cut up the car to me.

What kind of mileage are you getting out of a fuel pump that makes this worth it?

I love it when the southern crowd gets to wondering why mods like this are good insurance,..

The same crowd that doesn't even know what the green monster can do to wiring etc,..

I wish i was one of that crowd,...i,m fed up with the mid north climate,. far north is fine, dry and cold,. but the incessant up and down crappy temp weather gets aggravating,...It'd be nice to drive one nice car year round,. like a low mile fleetwod,.

The hole shown is in the DONOR CAR......I wanted to get the biggest possible "hat" piece to overlap the entire hole in another car...... I've used compression fittings to make "dual feed" manifolds for several Holley double pumper installations and they work fine..... I've even used them on power steering pressure lines (twice) and never leaked a drop....... I'm not trying to attack anybody's method of solving a problem, I just thought that if I can improve on the basic idea, I should maybe share it.....

phantom 309 wrote:

RedandBlack wrote:

That sounds like a lot of work when you could just buy a readily available sending unit and not cut up the car to me.

What kind of mileage are you getting out of a fuel pump that makes this worth it?

I love it when the southern crowd gets to wondering why mods like this are good insurance,..

The same crowd that doesn't even know what the green monster can do to wiring etc,..

I wish i was one of that crowd,...i,m fed up with the mid north climate,. far north is fine, dry and cold,. but the incessant up and down crappy temp weather gets aggravating,...It'd be nice to drive one nice car year round,. like a low mile fleetwod,.

I don't understand this thread......

Well this thread has taken a weird turn, hasn't it?.....
I live in one of the hottest places on earth and the underside of my wagon looks just like the picture.... I also know that a complete new tank module including a new sender and metal lines is available from RockAuto for about $65 (I know this because I just replaced the one in the "compression fitting" picture because it was rusted inside the tank)
I think the point of the exercise is to be able to replace the pump or sender without having to drop the tank and make it a "side of the road" repair instead of requiring the services of a tow truck (the overhangs make loading onto a rollback without damaging the wagon a real challenge)

Just found this thread, PM sent for one of those patterns. Great mod.

I'll be dropping the tank for about the fifth time that I have owned Shammoo. I WILL be doing this mod this time. Tom When you read this, Please send the pattern.

lakeffect@gmail.com

Thanks, Dave.

PS, I'll also take suggestions on upgrading the fuel lines from the sender nipples to the filter all the way to the AN fittings at the TPI manifold.

I will send them tonight Dave.  

Funny thing happen, well not so funny.  I bought a GMC Yukon XL (same as a Suburban), while we are down south for the winter.  I could tell by the way it was starting, the pump was loosing prime.  I found another forum where a guy cut the fuel pump door for a Suburban.  Well, the starting time grew longer and longer.  Today, I bit the bullet and had it replaced to the tune of $575......ouch.  But I didn't want any issues driving up north, loaded.

Tom

AzDon wrote:

What happened to the pictures and text posts I made to this thread?  My version of this modification was pretty good, bordering on professional quality....

Are you sure it was to this topic, and not a similar thread?
It is not like us to discard valuable info from our members.

Are the pictures you are looking for in this thread that you authored?

https://gmlongroof.4umer.com/t12677-fckn-fuel-pump-again