Fuel Tank Notes
2021 R. Kwas [Comments
Added]
Fuel Tank Configurations
122 Sedan Tank
122 Station Wagon
Tank
122 Wagon Fuel
Cap is non-vented
1800 Tank
1800E Tank
Pick-up Tube and Anti-Slosh
Compartment
1800ES Tank
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The Volvo Fuel Tank configured for use in an Amazon. Notice the arch
clearance on left...this is a strong suggestion that the same tank pressings were also
used for the 1800, where the vent fitting visible in the 1800 Tank picture, is located there (filler pipe enters Tank
below seam).
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122 Station Wagon Tank is somewhat unique, and shallow, and it looks like the (side) filler pipe is shorter than on the sedan...this could be the explanation why there is typically a fuel stain under the Fuel Filler of Kombis (and it is important to assure the Fuel Cap has a good seal to prevent this leakage and resulting staining).
The important difference to note in Sedans vs. Kombis: Fuel Cap on the Kombis are unvented to prevent spillage (there is a vent in the filler tube!), unlike the vented Fuel Cap of Sedans.
Picture Source: https://vp-autoparts.se/sv/artiklar/bensintank-amazon-220-kombi.html
122 Wagon Fuel Cap is non-vented!
My posting to thread: Rebuild Gas Cap https://www.swedespeed.com/threads/rebuild-gas-cap.640073/#post-7772390
"Wagons never had locking caps, so I deduce this is an aftermarket one which
a PO or you have installed...and knowing it's an aftermarket one, I also deduce
that it is vented, which they typically are...and herein lies the rub, this does
not play well with the relatively flat Tank and Filler, and is likely cause of
your leakage! Factory wagon Fuel Caps were not vented...that is not to
say Kombi Tanks were not vented...they were!...but in the filler neck and
occurring behind the Cap (which must do its intended function without making a
mess). I suggest your leakage is from the vented Cap which you could address. I
would suggest rebuilding it, and while you have it apart, you will undoubtedly
see the venting provision, which you should defeat before reassembly. Please
take and post pix of Cap rebuilding!
Naturally, the sealing of the rubber gasket between Cap and Filler is important
and must function well. You may need to adjust or replace with thicker to assure
sufficient preload.
From the Exploded Assembly Diagrams at GCP.se site:
Tank venting is routed from Fuel Filler, behind interior panel, not by way of a
vented Fuel Cap!
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1800S Tank, with Filler entering the Tank below seam and just above it
the Vent connection. Note area for 122 Filler location.
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Pick-up Tube and Anti-Slosh Compartment
Picture of the inside of a tank from an injected 1800, showing Anti-slosh compartment with fuel pick-up. Second picture shows fuel return from Fuel Pressure Regulator of the Bosch D-Jetronic Injection System. Two big general tank baffles are also apparent.
Source of (2) pictures: http://www.gas-tank.com/Links2009/Volvo.htm
Internal anti-slosh compartment. Fuel return has been reinstalled, and it
also feeds into anti-slosh compartment. Notice at
Green, Fuel Pick-up tube enters the chamber at the very bottom, as well as
the very small fill-holes next to the tube which
allow replenishing the anti-slosh compartment from the main Tank volume.
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1800ES Tank with in-tank Prefilter (1973 only? to be confirmed!)
The following four pictures and info for 1800ES tank were kindly supplied by Jim Perry:
'73 ES Tank topview, visible is the Senderhole.
Same Tank bottom view, showing both the central Drain, and the Sump with
Prefilter location.
Prefilter can be simply pulled from Feedtube, after removal of Sumpplug.
Any particles of contamination which have been sucked onto Prefilter fall into
the sump when suction from the pump is no longer present, so will be inspectable
after removal of Sumpplug.
Note the difference both in the threading and tool necessary for
installation/removal in the OE brass Sumpplug, and those of replacement Tanks.
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Solder Joint failures on 122 Sedan Tank:
Screenshot from Pieter Beeckx video used with his kind permission :
Common weakness of the 122 sedan Fuel Tank. Soldered joint at Filler Neck
to Tank. The solder fractures due to weight of the fuel filler pistol
being hung onto the filler.
This is less of an issue in other models, where the filler is better supported
in the body. A leak-test with water verifies the fractured solder joint at Filler Neck root.
My comments to a Faceplant
post.
Rick Watson Picture used with his kind permission.
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Answer to Faceplant
request for
details on gussets I mentioned.
Gussets support Filler Neck to seam, here. The fuel filler protrudes
through inner bulkhead, then outer body. No supporting rubber surround is
present yet in this excerpt of the R. Watson photo.
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From Thread: http://www.networksvolvoniacs.org/index.php/Spezial:AWCforum/st/id6591/Vacuum_im_Tank.html
Locking Cap partially disassembled, showing what certainly looks like a possible vent.
Picture credit: Rainer of the Volvoniacs Forum.
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Derusting Tank in preparation for internal sealing
If you are going to DIY...
Internal Tank cleaning of rust...strapping the tank to a cement mixer, with a few of handfuls of course stones for abrasive.
When using tank sealers, like POR15 subsequently, its critical to follow the sealer manufacturer's instructions to the letter...take no short-cuts, make no "judgment calls"!
Peter Bellinck photo...used with his kind permission!
Maybe unique, "rustic", and noisy, so should definitely be done "behind the
barn", but a very effective way of prepping the Tank interior for sealing.
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Update: Notes on a conversation with Joseph Moyer, long-time owner/operator of Moyer Fuel Tank Renu (http://www.gas-tank.com ). They bake out each Tank and prep by blasting, to give their baked-on internal plastic coating the best adhesion possible, and their work is guaranteed for life. They are located near Pittsburgh PA. Mr. Moyer tells me that the Fuel Filler behind the license plate of seventies GMs was similarly susceptible to fractures on the soldered-on filler pipe (soldering is apparently the typical manner in which fittings and pipes were connected to steel fuel tanks in the past. He has also reinforced such weaknesses with gussets [I guess great minds do think alike!...just saying!]
Knowing the internal condition of my 1800ES Tank, I intend to use their service when the ES gets next recommissioned...instead of changing to a new, but chinashit replacement Tank, guaranteed to last from 11 'til noon!...and he tells me the mounting holes of chinashit tanks often don't line up!...more of china's finest work! Watch this space for results of the experience!
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From a conversation with Don Thibault (www.p1800.com ) :
He stocks OE Tanks and just replaces them now..."they're all going on 50 years old now..." ...he's got a valid point there!
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Fuel Gauge Information and Notes
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External material sources are attributed. Thanks again to all contributors of pictures and information! Otherwise, this article is Copyright © 2020-2021. Ronald Kwas. The terms Volvo, and name of any other companies or individuals included here are used for reference only. I have no affiliation with any of these companies other than to try to keep their products working for me, help other enthusiasts do the same, and also present my highly opinionated results of the use of their products here [like the fact that china got it wrong again!]. The information presented comes from my own experience and carefully considered opinion, and can be used (or not!), or ridiculed and laughed at, or worshipped, at the readers discretion. As with any recipe, your results may vary, and you are, and will always be, in charge of your own knuckles and future!
You are welcome to use the information here in good health, and for your own non-commercial purposes, but if you reprint or otherwise republish this article, you must give credit to the author or link back to the SwEm site as the source. If you don’t, you’re just a lazy, scum sucking plagiarist, and the Boston Globe wants you! As always, if you can supply corrections, or additional objective information or experience, I will always consider it, and consider working it into the next revision of this article...along with likely the odd metaphor and probably wise-a** comment.
