joe_padavano

OK, I'm not proud of this one, but it worked.

To make a short story long, last summer the fuel inlet on the Qjet on my wife's 85 D88 started leaking. Fought with it for a while, finally pulled the fuel filter fitting off the carb and noticed what appeared to be a crack or score on the flare inside the fitting. Grabbed another off a parts carb and installed it. Now the leak was at the fitting to float bowl joint.

Pulled it out again and replaced the plastic gasket on the fuel filter fitting. All was good.

Fast forward to last weekend. The car stalled in the driveway and wouldn't restart. I finally found that it was massively flooding out - an obvious stuck float or debris in the needle and seat. After waiting for the carb rebuild kit and new float to arrive (NO ONE stocks carb kits anymore...), I rebuilt the carb. Found a sliver of the old plastic inlet fitting gasket wedged in the seat, holding the needle open. At least the flooding problem was easy to fix.

Reinstalled the carb, spent the usual hours tweaking the CCC system, and that's when I noticed the fuel inlet leaking again, from the flare nut area. Pulled that apart and carefully inspected the flares on the inlet tube and on the inlet fitting. Both appeared to be scored and pitted. This is a daily driver and I did not relish the thought of disassembling the front of the motor to remove that fuel tube (it snakes under miles of vac line plus the brackets for the A/C compressor and A.I.R. pump). I thought about the conical copper washers they sell as a flare seal, but didn't want to wait for them to arrive. I recalled something I'd read on another bulletin board about using an o-ring inside the flare fitting as a seal. It's a serious kluge, but what did I have to lose? I have an assortment of silicone o-rings that I bought a while ago and selected one that snugly fit inside the inlet fitting. I tightened the flare nut to compress the o-ring but not distort it. Amazingly, problem solved. My only concern is that the flare nut might loosen since it is not at the usual tightness for a metal-to-metal flare seal. I'll keep an eye on that.

I know there are people who put teflon tape on flare nuts, which is worthless since the seal is the flare, not the threads. In this case, the o-ring serves as a gasket between the distorted male and female flare surfaces. I also wouldn't recommend this fix on any system that sees a pressure higher than the 5-8 psi in a carb fuel system, as I have no idea how well it would hold up under those conditions.

oldcutlass

You might use blue locktite on the nut threads to keep it from loosening. I would probably get the copper washer and replace at the earliest convenience because if the O ring splits it will ****/spray a large amount of fuel.

joe_padavano

Good points. I wonder how the Locktite holds up to fuel exposure.

oldcutlass

It should be fine, the only exposure will be if there is a leak and at that point an insurance claim will probably be the next repair.

The locktite is just to keep the nut from backing out.

TripDeuces

Can you take a small piece of flared tube and use it as a lapping tool on the male flare in the carb with valve lapping compound? Use your flare tool on the line to make a new surface on it.
Sounds like you have a tight work space so may be impractical but at least you can remove the carb to get extra space.

Another idea is to use a Dremel tool with the cupped stainless wire wheel. It may be harder than the fitting seat and burnish it back into shape.

joe_padavano

Replacing the inlet fitting is easy. Replacing the tube from the pump to the carb is not. This is a daily driver and right now it needs to be functional. Once I get the 67 on the road, I can take this one down for a more permanent fix.