GTV-6 windshield-area leaks

[JHertzman@domain.elided]

In AD7-1344, 46, 47, and 48 Vangelis, Bill Bean, Bernardino Zelazninni and 
Jay Negrin discussed GTV-6 (and Alfetta) leaks around the windshield, cowl, 
and firewall, with Bernie suggesting on Bill Bean's car (where the windshield 
had been removed for painting) that "it's possible that they didn't seat the 
gasket properly when re-installing the windshield and this has led to your 
leak."

I don't know whether there are Body Shop Manuals for the 116 cars comparable 
to publication #1570 which covers the 105-115 coupes and sedans, but some of 
the information therein may be applicable. 

In #1570 there are eight pages on sealing, with about forty diagrams 
(sections of panel joints, etc) showing where each of three types of 
seam-sealers should be applied against either general leakage or potentially 
damaging rust-generating leakage. If this information exists for the 116 cars 
it would be good to know; if not, it is an argument for staying with the 
classic years - - but truly first-class bodymen probably have a good idea 
where such sealing helps. 

Also in #1570 there is a section on water testing with the vacuum pump P.N. 
M.6.0101. The general procedure is to tape-off any flow-through vents, fit a 
duct adapter in the top of one of the roll-up window openings, apply a vacuum 
(30mm of water in a U-shaped manometer) to the car interior, and hose water 
onto suspect points of the exterior. Should be easy enough to improvise on a 
GTV6, perhaps with more taping around doors and deck-lid.

Finally, on the windshield gasket, it is not just a matter of seating 
properly. There are five lips on the gasket; (105/115, I assume 116 is 
probably similar) two on either side of the glass, two on either side of the 
roof flange (where you use the popsickle sticks for removal and the cord for 
installing) and the fifth the outermost edge of the gasket which you see on 
the outside. Between this fifth lip and the fourth (the one on the outer side 
of the flange) there is a channel which is filled with a sealant applied with 
a sealant gun with a thin curved tip to put the sealant just where it is 
intended to go, covering the roughly 1/4" interface between the painted 
sheetmetal and the outer lip. The same sealant gun also applies the same 
sealant between the glass and the outer lip of the glass channel. Note that a 
windshield, with gasket properly installed will look exactly the same with 
and without this hidden last-step sealant. Note also that if this sealant is 
interrupted anyplace there will be a potential leak-path to the interior.

The applicator guns and proper sealants would be available through the 3M 
Bodyshop Supplies Catalog, and probably other suppliers to body shops. Jay 
Negrin's glass installer is of course right, you don't just go down to Home 
Depot for some bathtub silicone caulk. Probably glass installers - especially 
older ones, from the days of gasketed windshields (last used in production 
some fifteen years ago)  - know all this, and probably most are conscientious 
in doing the job thoroughly, but those are not necessarily always safe 
assumptions with archaic techniques.

The GTV-6 windshield gasket is also retained (against pop-out in accidents, 
and perhaps to aid in torsional stiffening) by four clips (P.N. 
11657.61598.00) which are pop-riveted in place and are completely hidden by 
the interior trim. I wouldn't be surprised if a lot of GTV-6s which had 
windshields removed for painting never had those clips replaced, and I also 
wouldn't be surprised if, over time, the sealing was less effective. Might 
be, might not.

Good luck staying dry -

John H.

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End of alfa-digest V7 #1350
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