gas leak - two questions

[mattn]

Smelled gas in the garage - found a slow leak which looks to be right behind the gas tank. The car is a 1972 911T that now has a 1986 3.2L with transmission. I say this only because the fuel line setup may not be stock. Haven’t jacked the car up yet but I see what appears to be the fuel pump right there behind the fuel tank and protected by a skid plate – in the vicinity if the leak.

My plan is to get it up on jack stands, remove the skid plate and identify the leak. I’ll plan on replacing the soft hoses and then the pump only if it is the cause of the leak.

Question: Is measuring the exterior diameter of the hose a good way to identify the hose size for replacement? Keeping in mind I can’t be sure it’s a stock fuel line setup.

Second question: Would like to save the full tank of gas I just put in. Any clever ideas on how to cap off or otherwise save the gas. Given the quantity (full tank) I don’t even have enough clean buckets at this point.

Thanks,
Matt

[Flojo]

guess a connection to the pump or in its periphery got shot (rust).
you'll need to check the inside diameter (not outside) for hose replacement.
guess you'll have to drain the tank, as its nozzle towards the pump is (obviously) set very low.

good luck.

[gomezoneill]

If it's the hose that's leaking get the proper hose cut it longer than needed put a hose clamping device on the hose then pull off your old hose and quickly install the new hose over the nipple. No need to drain tank. You'll lose a small amount of gas and of course it'll run down your arm.

[steely]

The 3.2 fuel tank/pump lines were simpler to me than the older setups in that they only have 2 connections instead of 3 or whatever, a short low pressure feed to the pump, and a higher pressure return line.

I think the ID measurement is best. 7 to 9 mm?
If you can't work fast, siphon off the gas to another car.
The stock tunnel lines are soft hoses with a crimp to harder polyimide, and a challenge to replace, but others have been successful in making some repairs before replacing the whole thing.

[Knockdown]

If it's the fuel pump, you can tape up the jaws on a set of vice grips to clamp off the supply line from the tank to the pump. I also tie wrap the vice grips so that they don't accidentally pop open. Then you can replace the pump.

If it's one of the lines to or from the engine bay, then these must be handled as high pressure fuel lines, some good threads on this site describing proper ways to replace these.

Don't use buckets for fuel, a closed container should only be considered.

[Mark Salvetti]

I think you're going to have to get under there and see what you really have. A 1972T would have had mechanical fuel injection with an electric fuel pump back near the engine, and I believe the fuel lines through the tunnel would have been steel.

I don't know if the steel lines could have been used with a 3.2 conversion (not sure they were large enough).

Either way, we probably can't help much until you get under there and see what is really leaking, and what kind of fuel line setup the PO left you with.

Mark

[jlex]

When I removed the skid plate to search for a small leak on my '88 a couple of months ago, it turned out to be the pump itself. Was leaking at the seam of the top plate. Tape on the jaws of the vise grip did just fine to hold the gas in the tank. Don't forget to disconnect the battery when you're fooling around with it.
Getting that skid plate back on is a real *****. Don't know the secret to that even though I used a bottle jack to take the tension off the suspension. Try not to cross thread the bolts

[mattn]

Thanks for al the advice. I'l be trying to fix this on Thursday. If all goes all you won't hear any more please for help…
Matt

[BoxsterGT]

Let us know what you find.

Len

[mattn]

Update - Got her up on jack stands and quickly diagnosed the problem as the pump. It is indeed a 1986 pump that accompanies the 1986 engine. On order from our host. I found a trick online when removing the old pump - I put a nail set (punch) into hose and clamped down on it with the hose clamp. That saved me from draining a tank full of gas. Pump should arrive Friday and hopefully installation will be as easy as removal.
Matt