1972 Vapor separator & hoses - drop the tank?

[Gary S.]

In an earlier post, I was inquiring about vacuum and idle and then this gas smell question got in the way, so a new thread is born.

I have read the archives and searched on the forum and it seems that the JB Weld on my fuel vapor separator has deteriorate enough that I can blow through the separator (what a pain to remove with the tank installed) and get a little air out. The JB Weld repair is still "mostly" intact but mostly doesn't count with gas fumes in the garage, both for safety reasons as well as my wife's complaining. I will be ordering a new one but one of the things I wanted to do was to replace the hoses since they are almost 43 years old. For those that have replaced the hose and/or separator, is the easiest way to get at them to drop the tank? I only have about 3-4 gallons in the tank and, now that the spare tire tub is off, this might be the time to drop the tank, replace the hoses and then re-install the tank, hoses, and vapor separator all at once.

So, has anyone done this? Can one drop the tank with the exhaust, rear bumpers and everything else in place?

[Terry M.]

Re: 1972 Vapor separator & hoses - drop the tank?

In an earlier post, I was inquiring about vacuum and idle and then this gas smell question got in the way, so a new thread is born.

I have read the archives and searched on the forum and it seems that the JB Weld on my fuel vapor separator has deteriorate enough that I can blow through the separator (what a pain to remove with the tank installed) and get a little air out. The JB Weld repair is still "mostly" intact but mostly doesn't count with gas fumes in the garage, both for safety reasons as well as my wife's complaining. I will be ordering a new one but one of the things I wanted to do was to replace the hoses since they are almost 43 years old. For those that have replaced the hose and/or separator, is the easiest way to get at them to drop the tank? I only have about 3-4 gallons in the tank and, now that the spare tire tub is off, this might be the time to drop the tank, replace the hoses and then re-install the tank, hoses, and vapor separator all at once.

So, has anyone done this? Can one drop the tank with the exhaust, rear bumpers and everything else in place?

I don't have the Vapor Seperator doohickey, but as I recall from removing the fuel tank I had to remove the rear part of the exhaust -- including mufflers as well as the spare tire tub. No involvement with the bumpers or bumper braces.

I can offer no suggestion as to whether the tank needs to come out to get to the doohickey, however.

[Gary S.]

Re: 1972 Vapor separator & hoses - drop the tank?

Thanks Terry,
You aren't going to let me forget that terminology "doohickey" are you. I guess I was being lazy in not looking the term up but ...

The spare tub is off and now I am looking at the mufflers to see how easy they might (not) be. Might need to coaxing and PB Blaster. They have been on for a long time, even before I bought it 14 years ago.

Gary

[Terry M.]

Re: 1972 Vapor separator & hoses - drop the tank?

Thanks Terry,
You aren't going to let me forget that terminology "doohickey" are you. I guess I was being lazy in not looking the term up but ...

The spare tub is off and now I am looking at the mufflers to see how easy they might (not) be. Might need to coaxing and PB Blaster. They have been on for a long time, even before I bought it 14 years ago.

Gary

Gary,

If you had JB weld on your doohickey (boy, does that sound strange, but I couldn't resist) you got up in there somehow. I have never been there, and I don't want to. I have no idea how it attaches to the tank or how many hose(s) there are or what clamps are there. You are on your own for that. My advice was/is pertained to the tank. I had other work to do in the area (someday I'll tell all of you about how to get 32 gallons of fuel into a C3 ) so I removed the rear exhaust pipes and mufflers.

Someone else on here has been there and done that -- changed the vapor separator -- because there have been threads about it. So there is no need to pay attention to my ravings since they only marginally address your question(s).

[Gary S.]

Re: 1972 Vapor separator & hoses - drop the tank?

Terry,
Perhaps my wording in the OP was off but I have removed the vapor separator (no idea what this "doohickey" term is that you keep using) and it is sitting on my work bench. That is done mostly by feel without any regard to cuts and bleeding thanks to the sharp edges of the fuel tank. The idea was to replace the old hose while I was there and the only way I can see to do that is to drop the tank.

With regard to your prior tank drop, is there some time honored method to get the exhaust pipes to separate, either at the muffler joint or just aft of the last frame pass-through? I can't see using heat because of the proximity of the fiberglass and fuel tank with the fuel vapors that caused the original question, so maybe pipe wrench?

thank you,

Gary

[Tom L.]

Re: 1972 Vapor separator & hoses - drop the tank?

I replaced my Doohickey without dropping the tank or tire tub. I did unbolt the exhaust hanger so it could move a little. You'll have to be creative in your positions to get your arm up there and you'll be working blind. It's held on with two screws, 5/16" head, and the hoses have spring clamps. Might be an idea to try to get some pics so you'll have a reference since seeing it is challanging at best. good luck!!

[Patrick H.]

Re: 1972 Vapor separator & hoses - drop the tank?

I replaced my Doohickey without dropping the tank or tire tub. I did unbolt the exhaust hanger so it could move a little. You'll have to be creative in your positions to get your arm up there and you'll be working blind. It's held on with two screws, 5/16" head, and the hoses have spring clamps. Might be an idea to try to get some pics so you'll have a reference since seeing it is challanging at best. good luck!!

Same here. If it's on a lift it is a lot easier to reach up, but I just dropped the exhaust a bit and then reached up to work on it by feel no matter how the car was suspended. Way too much work to drop the tank if you ask me.

[Gary S.]

Re: 1972 Vapor separator & hoses - drop the tank?

Tom and Patrick,
The vapor separator is out. Period! It comes out more or less easily by blind feel. Now I am into dropping the tank to replace suspect fuel lines and the new question is how to remove the exhaust at the frame or muffler? Since I have been getting pretty heavy fuel smells I want to ensure that all suspect components are replaced.

[Paul Y.]

Re: 1972 Vapor separator & hoses - drop the tank?

Yes, loosening the rear hangers and the clamps if any on the mufflers and even on the transmission hanger has all helped to get the exhaust system to be able to be moved enough to work around that area. Dropping the tank is not too bad if you can lower the mufflers etc. out of the immediate area. If they are welded as original though it is not nearly as easy and may be quite impossible.

[Terry M.]

Re: 1972 Vapor separator & hoses - drop the tank?

Tom and Patrick,
The vapor separator is out. Period! It comes out more or less easily by blind feel. Now I am into dropping the tank to replace suspect fuel lines and the new question is how to remove the exhaust at the frame or muffler? Since I have been getting pretty heavy fuel smells I want to ensure that all suspect components are replaced.

If the vapor separator is out and bolts to the tank then the hose to that will go to the pipe line that runs down the driver's side frame rail. You will have to find where the metal and rubber meet. Look through the driver's side rear wheel well. Might be you have to take that wheel off. I would expect the same kind of spring clamp
.
The fuel supply line is on the bottom of the tank on the rear passenger side. Removing this hose will drain your fuel tank, so be prepared.

The fuel (liquid) return line attaches to a short pipe that comes out of the passenger side of the tank near the top. This might be another blind reach for the spring clamp. The steel liquid return line runs on the passenger side fuel rail. This might be another rear wheel to come off.

Some have told me that the replacement hose is a larger diameter than the original and the original spring clamps would not work. I didn't get into exactly what kind of hose they used, so I don't know for sure if you will have that issue or not. Take one of the spring clamps with you when you get the new hose. That way you can get larger clamps if needed.

[Patrick H.]

Re: 1972 Vapor separator & hoses - drop the tank?

Tom and Patrick,
The vapor separator is out. Period! It comes out more or less easily by blind feel. Now I am into dropping the tank to replace suspect fuel lines and the new question is how to remove the exhaust at the frame or muffler? Since I have been getting pretty heavy fuel smells I want to ensure that all suspect components are replaced.

It's just as easy to replace the lines as it sits in place, because they are too short to be able to "hang" with the tank once you drop it. You're just creating more work for yourself. This is courtesy of the "don't ask how I know this" aka "been there, done that" school of car repair.

[Gary S.]

Re: 1972 Vapor separator & hoses - drop the tank?

The answer is that the tank can be removed without removing the exhaust. Tilt to the right, tilt to the left and the repro OL Anderson tank is out. I'll use Duke suggestion for hose, order new gaskets and VAPOR SEPARATOR thingamabob.

[Gary S.]

Re: 1972 Vapor separator & hoses - drop the tank?

Well just FREAKING never mind all the previous post of mine. I don't need new hoses - I need a new tank. I was cleaning up the old one in preparation for new hoses and re-hanging when I spotted a suspect area of rust. I flicked it and voila - daylight. It is about 1/4" long and maybe 1/8" wide right next to the strap hanging indent. In the attached photo, you can see the hole, just to the left of center and in the center vertically. The tan/red color that you see in the middle is the brick on my garage.

Off to Quanta Products LLC for new tank, gaskets and I might as well get a new cap while I am at it. What else will I need? I think I will get another O L Anderson http://www.gastanks.com/1970-1972-w_...ctinfo/GM-33F/ but other than a few bucks, is there any difference between the non-branded and the OLA? Just curious.

Added, it looks like Quanta gives the two seals but not the filler neck. According to their site, unvented cap. Joe L, can you confirm this?

[Tom L.]

Re: 1972 Vapor separator & hoses - drop the tank?

Like we all said, drop the tank. It probably needs to be replaced anyway : )

[Leif A.]

Re: 1972 Vapor separator & hoses - drop the tank?

Gary,Glad you found the leak...that could have gotten real ugly, real fast.