TheSamba.com :: View topic - Fuel sender access hole, to do or not to do?

Sun Jun 07, 2020 9:55 am

Honestly, it's the second most useful hack I've done to my car, behind only the phone charger. I had to swap out three senders in the last two years. (One float sunk, one float seized, one melted!) Here's Mr. Melty being installed; sure wouldn't want to do an engine pull here.

Amskeptic wrote: I wonder if a part gets made and it knows it's defective, and already feels bad about what it's going to do…

The access hole gives me options. A couple tools in the glovebox, and I can find the prettiest place to bitch about parts, instead of at home where the neighbor's kids play in our driveway…

Since I saw my needle hit full for the first time, I have not regretted it for one second.
Robbie

Thu Jun 11, 2020 8:11 am

Prepping to cut the access hole, my plan is to use my oscillating saw with a metal blade, oiling the teeth and cutting surface with WD-40, which will minimize the risk of sparks above the (almost empty) gas tank. That will also allow straight and square plunge cuts at the corners for a clean square hole.

As far as alignment to above the fuel sender, it seems like most people have gone with an alignment just to the right of the rib directly in front of the hatch pin, so the hole will be offset just to right of center. And I'll be cutting right about 1" back behind the edge of the "hump". Does that seem right to the group here? Any suggestions or recommendations?

Note, I have a 1972 Bus, but have installed late Bay F.I fuel tank.

Here's a few pictures of the mock up:

Thu Jun 11, 2020 9:11 am

Here are some dimensions from when I did this a couple of weeks ago...

Thu Jun 11, 2020 9:58 am

SLVRSRFR wrote: Here are some dimensions from when I did this a couple of weeks ago...

THANK YOU!! Exactly what I was looking for.

Thu Jun 11, 2020 9:17 pm

The ebay guy has a unit for up to 67 and another from 72 on. What about the early bays? Is there a difference?

Fri Jun 12, 2020 6:05 am

gsun wrote: The ebay guy has a unit for up to 67 and another from 72 on. What about the early bays? Is there a difference?

There is a difference, although I'm not sure what it is, so maybe someone can chime in there. If you have a pre-72, I guess your options are to make your own sender hole and get creative for the cover, or don't do it and pull the tank.

Mon Jun 15, 2020 9:15 am

Done.

Not my best work...but not bad, using my oscillating saw with a metal blade did well and made a clean cut, but it was a little tough getting that first plunge and the blade wanted to bounce around a little. Not a big deal once I got through the metal and was able to make nice clean straight edge cuts and clean 90 degree cuts at the corners.

The saw made very small and very few sparks, and I ended up pulling the firewall for some fresh air, and using wet towels and some steel plate when I drilled the holes for a little insurance. I do have some video I'll edit and throw out on my YT channel at some point.

Thanks all for the measurements, they were very helpful - I ended up going pretty much right in the middle of the top, and it landed the hole just to the left of the fuel sender, but I had zero issues accessing or pulling the old sender, so I'm really happy with the install.

Not quite finished with the install...I'll clean up my pencil marks, paint the raw edges of the steel and be sure the top plate seals up tight and that's really all that's left.

Thanks to you guys that gave me some measurements to work from, and thanks to user ecdez for fabricating an awesome solution for this issue.

Sun Jul 26, 2020 5:14 pm

All,
I'm about to cut this hole this week. We have a 76 FI motor. Reading through this thread there seems to be some clouds about where the hole is to be located when earlier bus vs later buses.
I have a 4.5" metal hole saw and so need to be pretty spot on. Does anyone have the EXACT location to put me dead-center above the sender unit on a 76 with a FI motor?
Thanks so much.

Sun Jul 26, 2020 5:46 pm

the next time someone talks with the manufacturer a couple simple suggestions.

Countersink the holes and use bolts that pull down into those countersinks. That would make it less a snag if you reach across it or side a mattress or air mattress on it.

Change the design to allow for a gasket. In any kind of a fuel spill in the tank area, fumes will find their way up if that plate is not sealed. Sure someone can RTV it but how messy. if the plate is cut down a little for a gasket, and one provided that will seal it and there is no clean up before the next time. An alternative would be to cut a groove to put RTV into to let it dry before putting the plate on, like valve covers are made these days.

Sun Jul 26, 2020 6:09 pm

Quote: the next time someone talks with the manufacturer a couple simple suggestions.

Countersink the holes and use bolts that pull down into those countersinks. That would make it

That or locate the bolts in the valleys

Otherwise the mesures in the couples last posts are good no need to be exactly spot on there is room...

Sun Jul 26, 2020 7:28 pm

wagohn wrote: All,
I'm about to cut this hole this week. We have a 76 FI motor. Reading through this thread there seems to be some clouds about where the hole is to be located when earlier bus vs later buses.
I have a 4.5" metal hole saw and so need to be pretty spot on. Does anyone have the EXACT location to put me dead-center above the sender unit on a 76 with a FI motor?
Thanks so much.

In my pictures posted above...if I was to move the access hole one more rib to the passengers side, I would have been almost directly over the sender hole. The tank sender is set just slightly to the passengers side on the FI tanks. However, I can still access the sender just fine, and I like the symmetry of the access hatch being in the middle, so in my opinion if I were to do it over, I would cut it the same.

I don't think I have any info in the pictures or measurements for reference on where I cut the access hole...but give me a couple of minutes and I can pull my rear cover and take a few pictures for you.

Sun Jul 26, 2020 7:48 pm

SGKent wrote: the next time someone talks with the manufacturer a couple simple suggestions.

Countersink the holes and use bolts that pull down into those countersinks. That would make it less a snag if you reach across it or side a mattress or air mattress on it.

I see your point, but respectfully disagree. The round head 4mm screws in the kit won't catch on anything. Plus, I'm not sure how successfully you could countersink screws in the thin metal.

SGKent wrote:
Change the design to allow for a gasket. In any kind of a fuel spill in the tank area, fumes will find their way up if that plate is not sealed. Sure someone can RTV it but how messy. if the plate is cut down a little for a gasket, and one provided that will seal it and there is no clean up before the next time. An alternative would be to cut a groove to put RTV into to let it dry before putting the plate on, like valve covers are made these days.

Great idea! Gaskets would be a great addition.

The kit is already a pretty good fit, but to mitigate any fumes, I was thinking about going back with some Permatex #2 and sealing it up a bit more.

Sun Jul 26, 2020 8:56 pm

Quote: I see your point, but respectfully disagree. The round head 4mm screws in the kit won't catch on anything. Plus, I'm not sure how successfully you could countersink screws in the thin metal.

the screw heads will snag Westphalia material on a mattress. I promise that.

You don't countersink the sheet metal. The aluminum gets countersunk and the screws pull the sheet metal down into the countersinks. One can use a tool to pull the sheet metal down if they want to. It is called a dimpling tool.

Sun Jul 26, 2020 9:31 pm

SGKent wrote: Quote: I see your point, but respectfully disagree. The round head 4mm screws in the kit won't catch on anything. Plus, I'm not sure how successfully you could countersink screws in the thin metal.

the screw heads will snag Westphalia material on a mattress. I promise that.

You don't countersink the sheet metal. The aluminum gets countersunk and the screws pull the sheet metal down into the countersinks. One can use a tool to pull the sheet metal down if they want to. It is called a dimpling tool.

SGKent wrote: the next time someone talks with the manufacturer a couple simple suggestions.

Countersink the holes and use bolts that pull down into those countersinks. That would make it less a snag if you reach across it or side a mattress or air mattress on it.

I seriously doubt those quality button-head screws would snag the Westy fabric. If a user somehow damages one with a slip of the tool, he/she should kiss it with a file to knock any potential burr down.

And, the part is already countersunk on all 14 holes for anyone who may want to venture down that path. However, the problem with using flat-head screws is, every single hole in the sheet metal needs to be absolutely dead-nuts so that the conical underside of each screw is concentric with the threaded holes below, and the holes that you'd hypothetically "dimple," and so that each screw is certain to line up and screw STRAIGHT down into the threads below, otherwise the user will be "ovaling" the holes that weren't dead-on with the pattern of the aluminum flange. Also, you'd definitely need to preform the countersinks in the sheet metal, otherwise one risks stripping (or at the very least, compromising) the threads in the new aluminum flange, because that thick sheet metal is going to take hella force to deform the size of countersink that would be required for such a flat-head screw to lie flush - or below - the surface...then you WOULD have a snag hazard on the less-than-flush screw heads. That type of exercise would be akin to using lug nuts to pull Dorman studs into a forged steel hub.

So long as the user deburrs all sheet metal cuts prior to reassembly, a simple, clean bead of RTV in the resulting gap between sheet metal edges would suffice to eliminate fuel odor and any fume passage.

Sun Jul 26, 2020 9:50 pm

SGKent wrote: Quote: I see your point, but respectfully disagree. The round head 4mm screws in the kit won't catch on anything. Plus, I'm not sure how successfully you could countersink screws in the thin metal.

the screw heads will snag Westphalia material on a mattress. I promise that.

You don't countersink the sheet metal. The aluminum gets countersunk and the screws pull the sheet metal down into the countersinks. One can use a tool to pull the sheet metal down if they want to. It is called a dimpling tool.

Yeah still not sold on that...the 4mm flanged bolt heads are smooth and don't have any sharp edges or corners to catch on much of anything. The cut edges of the hatch panel would snag material before the bolt heads would, so I'd be more worried about that. I took a file to edges of mine to deburr and smooth out the edges, but it's still a bit rough.

If someone is worried about snagging their illustrious Westphalia material, then they would find a way to smooth out the panel and screws. Besides we both know that any respectful card-carrying member of the Yellow Bucket Club would never cut such a sacrilegious access hole. :lol:

Mon Jul 27, 2020 6:19 am

since it is already countersunk then the path is to dimple the holes with a low profile countersunk bolt.

here is an example of a dimpling die. One only needs the correct size and a way to squeeze them together. It could even be an add on sale for the folks who sell the plate.

Mon Jul 27, 2020 8:26 am

I see both sides of the argument concerning the fabric cushion. However the vinyl cushion found on early Campmobiles. I’m not so comfortable with the raised heads. Might cause it to dimple the vinyl, causing a weak point with weight on it over time. Also the constant back and forth motion on the cushion in the middle of the night :wink: :lol:

Mon Jul 27, 2020 6:47 pm

Xevin wrote: Also the constant back and forth motion on the cushion in the middle of the night :wink: :lol:
:lol: :lol: :lol: In your dreams, Xevin :lol: :lol: :lol:

(just kidding, buddy :wink: )

Sun Aug 02, 2020 3:19 pm

I cannot seem to find the exact location to cut and access hole for my sending unit on a 1971 bus? There was one remark stating that the measurements given by "someone" was incorrect for his '71 finding out "after" he cut the hole. Does anyone know where to cut the access hole on a '71 bus? Thanks for any information.

Sun Aug 02, 2020 3:30 pm

Hua Hin wrote: I cannot seem to find the exact location to cut and access hole for my sending unit on a 1971 bus? There was one remark stating that the measurements given by "someone" was incorrect for his '71 finding out "after" he cut the hole. Does anyone know where to cut the access hole on a '71 bus? Thanks for any information.

consider

Tcash wrote: Early

Late
Thanks to Speedy Jim's

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