Write-Up: Fuel Pump/Sending Unit (NA Series II)

I recommend replacing the tank. It's very common for the retaining ring to rust off on northern Riv's and Park Ave's. And replacing the tank is the only way to fix it right. Anything else is playing with fire.

So tank aside, where can I get just a replacement pump and not the whole sending unit? It seems extremely easy to get an L67 pump, but the L36 looks to be a real pain to find.

Not sure. I'm surprised to see even on RockAuto there aren't any listings for pump only. You can try car-part.com for used.

Could I put an L67 pump in this car? This is the pump I was looking at:
Link

That eBay pump is awfully tempting... The seller has a pretty good feedback rating, and he lists a whole bunch of pump module assemblies that it will fit.

Whenever one of us has tried to buy just a pump, or just a sender, without blowing $300-400 to replace the whole module, it's been a pain in the ass. I've never even seen a nice Delco "pump repair kit" like this before, and Google doesn't help much, either... though they sure as hell OUGHT to be more advertised and available!

This kit appears to have everything necessary to fit it into the existing module, right down to the seal-ring for the tank. All you'd need to get from the dealer/RockAuto/etc would be a new locking cam.

Hell, I'm tempted to buy one myself just to have on hand for my L67 - and if you didn't want to put the higher-output pump in your car, the seller has kits as low as $36 for other, normally aspirated 3800 applications...

You shouldn't have any problem installing the L67 pump in your housing. You won't find one cheaper that's for sure.
If someone on here has had an issue with putting an L67 high output pump in a non-S/C cartridge please speak up. I haven't heard of any differences in the cartridges just the output of the pump is higher, but that will be controlled by the Fuel Pressure Regulator.
Just my thoughts on it.
If I didn't already have a New Pump on the shelf, I'd be buying one of these as a spare.

For the price, I'll give it a shot. Hell, if it doesnt work it becomes a spare for my L67. As for the tank, I gotta go take a look at it and clean the top off some more and see just how many retainers are left and what shape they are in. I'll keep you guys posted on my findings.

moldymac wrote:

For the price, I'll give it a shot. Hell, if it doesnt work it becomes a spare for my L67. As for the tank, I gotta go take a look at it and clean the top off some more and see just how many retainers are left and what shape they are in. I'll keep you guys posted on my findings.

Suggest you get a new locking ring (Delco # TR7) and o-ring (Delco # G13) before you start. You can set the ring over the pump module while it's out of the tank to see how it goes together. Some of the cam locks onto the pump and some locks in the tank. Until the tank opening is cleaned off you can't really tell. Most likely you will need/want needlenose pliers to pull those metal bits out of the tank top. I would wear a ground strap to avoid static sparking - Radio Shack has them and tell them you want pn 210-3245. They are $6.- plus tax. Cinch it on the wrist that's holding the pliers. Touch hand to pliers' metal before yanking on the'metal bits still stuck around the tank opening.
And set up a fan to blow air in to the trunk

Anyway - I think if the shop did not actually break anything on the tank opening, when you get it cleaned off you will find it all goes back together fine. I am concerned about those plastic tabs around the opening and dont remember if they were for locking or alignment. Someone who's more recently pulled a pump should comment.

A little more - The locking ring IIRC spans the pump module top and the area around the tank opening, which is not real obvious when the tank top is so dirty and bits of the metal ring remain. That metal ring is basically disposable and when you have it all out IIRC the tank top's all plastic around the opening.

As for replacement tank, might want to contact Ed Morad just to ask what they might have.

I agree with Eldo's comments about the pump repair kit, looks like it should work. I have not used one but I'd try it.

My thinking is you picked up a screaming bargain for $200 and you'll have it back on the road with a bit of effort. And a lot of ventilation...

Albertj

Just a reminder, the O-ring is supposed to come with this kit... I've also seen other parts at Napa or RockAuto that come with it, like the filter socks or the sending unit.

More importantly, while I was researching this item, I found a new tank for $700!! Buy that $200 tank!

You guys have what sounds like the right solution here. I didn't realize you could replace the locking ring, that's great news.

deekster_caddy wrote:

You guys have what sounds like the right solution here. I didn't realize you could replace the locking ring, that's great news.

Nay, we're talking about the other locking ring, the one you remove to take the pump/sender module out... Not the ring that's molded into the top of the tank.

Eldo wrote:

deekster_caddy wrote:

You guys have what sounds like the right solution here. I didn't realize you could replace the locking ring, that's great news.

Nay, we're talking about the other locking ring, the one you remove to take the pump/sender module out... Not the ring that's molded into the top of the tank.

Oh, eegads. I can't read.

Sorry

deekster_caddy wrote:

Eldo wrote:

deekster_caddy wrote:

You guys have what sounds like the right solution here. I didn't realize you could replace the locking ring, that's great news.

Nay, we're talking about the other locking ring, the one you remove to take the pump/sender module out... Not the ring that's molded into the top of the tank.

Oh, eegads. I can't read.

Sorry

Just thinking out loud:

Maybe there is a way we could get a pattern and have a replacement made out of a steel place - maybe a piece of T304? Caulk/pop rivet it into place?

Trick would be to find a pattern and either cut it yourself or find a tech who likes the idea to do it. I have no idea what this would cost vs. getting a replacement tank.

Also - the tank straps on the Riv fit a nuber fo cars (Lucernes, Caddies, etc). I kind of wonder how many tanks, even though they are not exactly the same shape, would fit in the space?

Albertj


Albertj

Have you thought about the complexity of duplicating the gas tank side of the retaining ring with the lifted and twisted locks.
Maybe a Metal Fab shop with either the blueprint of that part (expensive) or a brand new tank to copy from (more expensive) along with the proper heat treatment, etc.
Yes, if we had the factory blueprint/drawing of that piece that not only specifies Dimensions but also Bill of Materials and Heat treatment and we are going to mfg enough of them, we could bring cost down. But I don't see that happening unless someone can get a hold of the GM blueprint. That would be the start, I would say.
Or if someone could take the time on a new or near new tank and reverse engineer the blueprint of the tank locking ring.
I have a large Metal fabrication shop available to me who can make almost anything. Just happens to be my old welding teacher that made it big.
Nothing is free though.

moldymac wrote:

For the price, I'll give it a shot. Hell, if it doesnt work it becomes a spare for my L67. As for the tank, I gotta go take a look at it and clean the top off some more and see just how many retainers are left and what shape they are in. I'll keep you guys posted on my findings.

When all this comes together David, don't forget to give us a report on that eBay pump!

Rickw wrote:

Have you thought about the complexity of duplicating the gas tank side of the retaining ring with the lifted and twisted locks.
Maybe a Metal Fab shop with either the blueprint of that part (expensive) or a brand new tank to copy from (more expensive) along with the proper heat treatment, etc.
Yes, if we had the factory blueprint/drawing of that piece that not only specifies Dimensions but also Bill of Materials and Heat treatment and we are going to mfg enough of them, we could bring cost down. But I don't see that happening unless someone can get a hold of the GM blueprint. That would be the start, I would say.
Or if someone could take the time on a new or near new tank and reverse engineer the blueprint of the tank locking ring.
I have a large Metal fabrication shop available to me who can make almost anything. Just happens to be my old welding teacher that made it big.
Nothing is free though.

Very good points.

I am thinking the "solution" might start with identifying the OEM. I kind of doubt I will succeed but I will start looking into it today. All I plan to do is look into whether the tank maker (or theri subcontract metal shop) ever considered making repair rings for the trade, for these tanks.

Basically if the on-tank ring is the same for a bunch of models, some sort of repair plate should be made available to the trade. It would save people headaches. I kind of wonder if NAPA has something like this already & we did not know to ask for it...

I sent an email to a contact at Dorman about this, let's see if I get a response.

Albertj

I think Dorman has a deal like Lisle (the tool makers), if you think up a product or tool you can be compensated for it if they deem it to be a useful and profitable item.
You never know Albert, it could be the ticket. Good Luck finding the data.

might know more tomorrow...

Albertj

Eldo wrote:

moldymac wrote:

For the price, I'll give it a shot. Hell, if it doesnt work it becomes a spare for my L67. As for the tank, I gotta go take a look at it and clean the top off some more and see just how many retainers are left and what shape they are in. I'll keep you guys posted on my findings.

When all this comes together David, don't forget to give us a report on that eBay pump!

It hasent shown up yet, shipped out monday though. I'll let you guys know how the pump worked out, if all goes well I might have to buy a spare for myself! I have access to a metal shop at my work and one of the guys is helping me make a replacement retainer for the sending unit. The idea as it stand now is a metal ring that would bolt onto the tank and press down on the sending unit (the aftermarket tank on my truck is similar). The ring we are making stainless. I am still working on a way of securing it. I can just use nuts and bolts, but not sure what to do to tighten them, its a bit hard to get a wrench inside a closed tank. I am thinking some sort of stud that can be fulled up through the plastic that woul grip the tank once its in place (same idea as lug studs on your wheel hub). Gotta see what might work.

You could use Riv-Nuts for this job.
I will have to find a photo of them if you are not familiar. You drill the hole for them, then you insert a threaded tool, similar to a rivet gun and squeezes the Riv-Nut and it pulls the bottom of it up tight to the inside of the tank. Now you have a female threaded hole with about 1/4" of threads to work with that are in the tank. You just would need to use some type of sealant that is impervious to fuel to prevent gas from wicking up the threads.
There are other types of fasteners that are made for the Aircraft industry for just this purpose. The nut plates are already sealed for fuel and are not open on the bottom (inside the tank). They would have to be sourced from an aviation parts store though and I don't have any of those catalogs anymore.
I use to work on aircraft as a living. A lot of good and specialty fasteners available for all kinds of jobs. But there are a shit load of different styles made specifically for fastening access panels onto the fuel cells.

I was thinking a little more about the Riv-Nuts and remember that they will not provide the flush surface at the top of the tank that you would need to seal the pump canister properly. You need to end up with a flush surface after installing the female fastener so the seal or o-Ring will seal the pump canister to the tank properly. The Riv-Nut would stand proud about 1/16" above the tank.
I'll keep thinking.

I found a package of heavy duty 1/4-20 Rivnuts in the garage. The washer face is 5/8"diameter and 1/16" thick.
If you could make another ring that is 1/16" thick and just drill 5/8" diameter holes where you want to install the riv-nuts then it could act as a spacer for these. Would just need to seal the spacer to the tank with sealer that will work in gasoline, I think these would work. Then you make the other ring that you already mentioned capable of accommodating 1/4" diameter bolts and apply sealant to the bolts and torque them in.
I don't know, but I could send you a handful of these to try and a small installation tool if you want.
If you need a pic to better visualize what I have let me know and I'll try to post one or two tomorrow evening.
Let me know,
Rick

Rickw wrote:

You could use Riv-Nuts for this job.
I will have to find a photo of them if you are not familiar. You drill the hole for them, then you insert a threaded tool, similar to a rivet gun and squeezes the Riv-Nut and it pulls the bottom of it up tight to the inside of the tank. Now you have a threaded hole with about 1/4" of threads to work with that are in the tank. You just would need to use some type of sealant that is impervious to fuel to prevent gas from wicking up the threads.
There are other types of fasteners that are made for the Aircraft industry for just this purpose. The nut plates are already sealed for fuel and are not open on the bottom (inside the tank). They would have to be sourced from an aviation parts store though and I don't have any of those catalogs anymore.
I use to work on aircraft as a living. A lot of good and specialty fasteners available for all kinds of jobs. But there are a shit load of different styles made specifically for fastening access panels onto the fuel cells.

I was thinking a little more about the Riv-Nuts and remember that they will not provide the flush surface at the top of the tank that you would need to seal the pump canister properly. You need to end up with a flush surface after installing the fastener so the seal or o-Ring will seal the pump canister to the tank properly. The Riv-Nut would stand proud about 1/16" above the tank.
I'll keep thinking.

...maybe could make a plastic spacer out of a plastic gas can or flat area from a scrap tank from a pick-n-pull, to go on with the metal plate with openings for those riv-nuts. A suitable sealer (I am still thinking butyl) could be applied to make it all gas-tight. Actually if you're confident, an epoxy meant for repairing plastic/metal gas tanks should work fine as a sealer come to think of it, with tank to plate and for that spacer.

At the moment I am thinking rivnuts go in the tank, spacer goes on the opening with holes punched for the rivnuts, cemented on with epoxy, then metal plate goes on top with a schmeer of epoxy to seal and screwed in place with the rivnuts. I am not at all sure though, would have to see the thing.

Another idea would be to use a fat bead of epoxy putty to fill the space between the plate and the tank top, around those rivnuts. Provided you can get things clean enough...

Given that you have a shop available I suspect you'll be able to make one or the other idea work fine. .


Albertj

Rickw wrote:

I found a package of heavy duty 1/4-20 Rivnuts in the garage. The washer face is 5/8"diameter and 1/16" thick.
If you could make another ring that is 1/16" thick and just drill 5/8" diameter holes where you want to install the riv-nuts then it could act as a spacer for these. Would just need to seal the spacer to the tank with sealer that will work in gasoline, I think these would work. Then you make the other ring that you already mentioned capable of accommodating 1/4" diameter bolts and apply sealant to the bolts and torque them in.
I don't know, but I could send you a handful of these to try and a small installation tool if you want.
If you need a pic to better visualize what I have let me know and I'll try to post one or two tomorrow evening.
Let me know,
Rick

Please post a pic of these, might be able to use these. Riveting a ring to the tank might work, just gotta seal the rivets somehow. I can press in threaded studs on that ring here, thats not a problem.

This should almost get you "there" as far as picture goes:

http://www.rivet-nut.com/Rivnut_Fasteners.asp

Look on right side of page.

Here are drawings and installation instructions to get you the rest of the way:

http://www.aircraftspruce.com/catalog/hapages/rivnuts.php

And the tool - I think the one at top of page would work, maybe Rick has other thoughts:

http://www.aircraftspruce.com/menus/to/rivnuttools.html

Now, back to your specific job: point is the washer side is 5/8" diam. and 1/16" thick on the rivnuts Rick has on hand. Maybe you need different ones depending on how the assembly measures up--AircraftSpruce stocks/sells them. Looks to me like Rickw nailed it as usual - for fairly short money this can be field-fixed without replacing the tank.

Albertj

PS: Figures they'd be called Rivnuts.

David,
Just PM me your address and I'll send you the Rivnuts I have and a small installation tool (made for field repairs and not production work) that you can keep.
If it doesn't work out on this project they might come in handy somewhere down the road.
It would be much easier for you if you have them in hand to determine if the 1/4"-20 will be too big or not for this flange. That's my only concern at this moment. Once you determine the correct size needed then we can move on from there.
OK, PM me with info and I'll ship these out.
If you could just cover the shipping cost, that would be appreciated.

Albert, thanks for researching and posting the info on Rivnuts. This should give David a much better idea as to how these fasteners work.

David, now you need to find some permanent sealer to use on the plastic gas tank and the first ring that you make, be it stainless or whatever kind of material you chose.