1977 cpe......Gas dripping from muffler on passenger side...I'm thinking rotted rubber hose(s) to tank....Does the tank have to be dropped to replace hoses?...I know water drain hose connects to top rubber collar ...are other hoses on the side somewhere or near top?..I took off spare tire and covers and still could not see lines anywhere except for the fallen water drain hose.thanks for your help...

BTW...had my '77 since 1980

 

the hoses connecting to the tank are on the passenger side. You need to place the car on a lift to see if the leak is from the hoses or the tank is rotted. If you can get past the exhaust you may be able to replace some hoses without dropping the tank.

 

Wow...that was fast......have it backed up on ramps...tank looks really good.....may try dropping muffler to see if I can reach hoses...thanks...

anyone else had to replace rotted hose to tank?

 

I know this part of these cars intimately over the past 7 weeks.

Put a jack under your tank with a nice wide board between it and the tank.
Remove the rubber neck from under your gas door
Take off the 4 gas tank cross member bolt's nuts (the cross member won't fall off with the straps through it- this is a good thing right now)
-SUPER slowly lower the gas tank 1 or 2 inches- you might have to wiggle it around to get it to come off the frame cross-over in the rear.

-Now inspect the rubber hose(s) (2) connecting from the stock steel fuel line and return line on the passenger-side of the tank to see if they're leaking (they probably are).
Get your needle nose pliers in there -drop the tank another inch or so, if you need to and pull those hoses off- might as well do the rubber line from the driver's side coming from the evap canister, too while you're at it.

Replace the crappy old rubber hoses with new ones, jack the tank back up, and screw down the 4 cross member nuts.


I think it's doable even without completely taking the tank out. -You might need to let your exhaust hang down and remove them from the hangers to get a little extra room to drop the tank a little (I took mine off first thing so I'm not sure it would be required for this job or not.).

Full disclosure, though: I just got too impatient with this job and didn't actually properly remove the hoses as I explained above. -I used a wire cutter to just cut the stupid rubber hoses in half so I could drop my tank (I needed a new fuel pump and it had to come out anyway).



Adam

 

OR: Take the whole tank out so you can easily inspect it and work on it, do rust remediation, and repaint it using Eastwood Tank Tone paint. (I'll send you 1 1/2 cans for $10. (I have 1 1/2 cans left over from my tank.) ;-)


Adam

 

Does it leak all the time or just when full or near full?

It's probably the hoses from the tank to the vapor separator valve and the rubber hose from the valve the the vapor return hard lines that run along frame. Most likely the hose that runs from the tank the the separator as the separator should stop liquid fuel from entering the vapor return line. It could also be your vapor separator valve is cracked.

 

It's probably time to replace all the rubber hoses up on top of the tank

 

Here's what the top of your '77 tank looks like. Try getting those hoses and clamps off without dropping the tank, I dare 'ya. Can't be done. Dropping the tank isn't hard.

 

are these molded? same size, or diff diameter?
it looks like this should be done before it starts leaking. real good post!

 

they are not molded you can pick up standard fuel hose at the autoparts. its 2 sizes(i foget size). They attach to steel lines going toward the engine. The hoses at the fuel pump/engine are molded S shape.

 

If you dont want to remove the tank, you can probably loosen/remove the straps enough to push the tank down so you can access a bit better through the sides and top(if you remove the gas door).

 

On my 80, I could get the hoses on and off without dropping the tank. In fact, you have to get them disconnected before you drop it completely. However, as noted in an earlier reply, you need to drop the tank a could inches first to get some working room. I'd try that approach first since, as I said, you need to do that before dropping it all the way. So no time lost.

 

Thanks for the insight guys...you C3 guys are great!...I guess the tank needs to be dropped and all hoses replaced...not sure yet if my '77 even has a vapor separator...eh...

 

No vapor separator.
If the hoses have never been replaced they'll be just about welded onto the fittings. Prepare to have to cut them off. Just lowering the tank and working through the top opening is really tough. It's tight. Be prepared with lots of band-aids.

 

gonna get it on a lift and drop the tank...after 41 years it deserves new hoses...old ones must be dry rotted by now...no wonder its leaking gas...just lucky the whole dang thing didn't catch fire dripping gas on the hot muffler...can't wait to get it back on the road... actually like it better than my C5...old school rumble sound and throaty sound of 4 bbl........crazy, right?...anyway after new hoses and a few other things, maybe a nice paint job...who in their right mind doesn't like the looks of a C3 with the coke bottle fenders

I have had it since 1980



Thanks again !

 

You might want to replace the filler neck gasket while you are at it. You did say you are dropping the tank, but that can also be done topside, just be sure not to drop any debris in the tank. I am kind of surprised your tank is still good. Mine rotted out at the base where it rests on the cross brace with the same result, gas dropping onto the mufflers. The military calls it a "thermobaric weapon". Quite spectacular.

 

Just to make life harder, be careful about scraping the back and top of the tank when dropping it. The build sheet may still be there and legible. Mine was. A nice historic document if you can retrieve it.

Here's a link showing mine including where I first saw it

https://www.corvetteforum.com/forums...tank-rust.html

 

So how did you do? Did you drop the tank out or just lower it bit? I did not lower the tank when mine leaked onto the muffler. I used a string and fished the hose's thru. Yea it was difficult but it can be done without moving/removing the tank.

 

Taking it in Tuesday...I cannot even see the clamp to loosen it on any of the hoses...you are way more talented than me...I can only get to the water drain hose that connects to the rubber collar...I guess I am going to have to bite the bullet....dagnabit......I will look again tomorrow with a flashlight to see if I can see the clamp(s)...Thanks for trying to help me...

looking underneath from the rear, I can see gas dripping from the right side frame rail onto the muffler when I run the engine...so it must be a hose on that side that is leaking.

 

Yes mine leaked from the right frame rail onto the muffler. I smelled gas in the garage and saw the stains on the right muffler. The hose had been repaired by the previous owner and you can see in the picture they did not get the clamp onto their connector far enough.