# How do I replace the “sock” at the fuel pick up?



## jimmy328 (Oct 12, 2011)

Been reading threads on the subject of “vapor lock” which I believe is the cause of my engine quitting after 25 or so minutes on the road. I think replacing parts as old as the vehicle (1967) is probable the best start. Carburetor not even a year old, pump working as it should, rubber lines between pump and carb replaced, rubber lines near fuel tank will be replaced but otherwise look okay. I could use “wrap” for the metal fuel and return line between pump and carb but doubtful this as an ideal fix.

I raised the back end and examined the section in the front of the fuel tank; one line to pump, a return line and an electrical wire (probable for gas gauge). But I don’t see how this unit can be replaced; I do not see screws or bolts. Perhaps the entire unit spins? Any suggestions?

Thank you,
Jim


----------



## chuckha62 (Apr 5, 2010)

There is a three tab lock-ring, that needs to be turned 1/4 turn (or so) counter-clockwise to release the assembly.


----------



## jimmy328 (Oct 12, 2011)

Cool, I'll look for it, thank you Chuck.


----------



## 05GTO (Oct 6, 2004)

Jim,

How are the lines routed thru your engine compartment?


----------



## BearGFR (Aug 25, 2008)

Also keep in mind, the locking ring and access to remove the fuel pickup and sock is on the top side of the tank. To get to it, the tank has to come completely out of the car.

Bear


----------



## fasterfiero (Sep 6, 2011)

67 has the sending unit/pick up on the front of the tank....... would be a pain to replace while in the car, but possible , Maybe you should pull and flush the tank, replace the sending unit...... then find out if this is what, is causing the vapor lock.......


----------



## jimmy328 (Oct 12, 2011)

05GTO: The fuel line and return line run from the fuel filter mounted on top of the intake manifold down along side of the block and water pump which then split; one to fuel pump and one through frame back to tank.

It doesn’t look too intuitive to remove the tank for easy access to the locking ring-fuel pickup. I guess the rear bumper can stay in place. Looks like only two metal straps keep it in place.

Fasterfiero: Flush the tank……with water? Is this to remove possible sediment? Makes sense, could be a lot undesirable substance after 45 years.


----------



## jimmy328 (Oct 12, 2011)

Now that I’m looking online for “sending units” it makes sense to replace this entire part rather than the “sock”. Don’t know though if it is a 3/8 or 5/16 inch line.


----------



## BearGFR (Aug 25, 2008)

My bad - I didn't know 67's were different like that. 

Bear


----------



## 05GTO (Oct 6, 2004)

When does your car shut down? While you are driving or after you have driven the car for a period of time, turn off the engine and it doesn't restart?


----------



## jimmy328 (Oct 12, 2011)

05GTO: The engine shuts down after about 20 to 30 minutes on the road (a really bad feeling on a 3-lane road with a curb and traffic). I bring it to a stop, try to restart, begins to fire up but doesn’t. After about a 10 minute cool down, it may go another 2 or so miles. After about a 30 minute cool down, it will run another few miles and shut down. This pattern tends to repeat itself.


----------



## chuckha62 (Apr 5, 2010)

Did this on a '73 Malibu back in the day... Took the inlet line off the input of the fuel pump, put a rubber hose on it and blew compressed air back through the system. I used my air compressor, not a can of air. It blew the sock clean off the end of the pick-up, because it was so plugged. Drove it for quite awhile (changing fuel filters regularly) until replacing the entire pickup.

If it doesn't blow the sock off like mine did, it should at the very least reinflate the sock and knock crud off of it. You will need to keep good filters on hand until you replace the pick up and clean your tank.


----------



## 05GTO (Oct 6, 2004)

I don't think your problem is vapor lock, your fuel lines are protected from the engine heat inside the frame and you also have a vapor return line. Vapor lock usually does not shut the engine down while driving, but if you stop for a few minutes the engine's heat will vaporize the fuel inside the fuel line.

Could be a couple things, like chuck said maybe a blockage from trash in the tank or you have a leak in your fuel line between the tank and the fuel pump. If you are drawing air into the rubber to metal tubing connection points it would cause the engine to shut down. Remove the fuel line from the sender unit and from the fuel pump and pressure test the line for leaks.


----------



## jimmy328 (Oct 12, 2011)

I just ran the engine in my garage at about 2500 RPM’s in the garage for about 20 minutes, came back about 25 minutes later and noticed gasoline leaking profusely beneath the fuel pump; however, the engine continue to run strong.
Further inspection I noticed the leak appeared to be coming from the return line rubber hose-metal line connection. The metal line appears to be ¼ inch and the rubber hose appears to be 5/16. There are two quality screw type clamps but still this may leave a gap for air to get through. Obviously I need to fix this problem first.


----------



## chuckha62 (Apr 5, 2010)

Good start! Get those kinds of issues taken care of first and you'll either cure it completely, or at the very least be better able to pin down your problem.


----------



## fasterfiero (Sep 6, 2011)

I would not flush it with water, rather slosh fuel or a solvent around so any crap comes out of the tank. Maybe compressed air or a combination of all three methods. OUTDOORS with lots of fresh air cause the vapors can be harmful and even potentially dangerous!!!!


----------



## jimmy328 (Oct 12, 2011)

Problem fixed.

The returned line had a 5/8” nylon tubing on a ¼” steel gas line.

My problem GTO was in storage at my dad’s house for 5 years. Before I re-took ownership a few months ago, he decided to have a GM “stealership” look over and “road-ready” it before shipping on a truck 300 miles (God love him for trying). The dealership was pleased to have the work and displayed it outside their work bays. They did a good job replacing the carb with a rebuilt Quadrajet, fuel pump, fuel lines (almost) and tires; could have done it all myself.

Anyway, for about $10.00, I put on ¼” high strength nylon gas tube with proper clamps between the filter and steel return line, got the engine “HOT” (210 to 220 F) in the garage for 30 minutes and no leak.


----------



## chuckha62 (Apr 5, 2010)

Excellent! Good to hear.


----------



## 05GTO (Oct 6, 2004)

jimmy328 said:


> Problem fixed.
> 
> The returned line had a 5/8” nylon tubing on a ¼” steel gas line.
> 
> ...


Good find, that beats the hell out of dropping the tank, replacing the sending unit and then having the same problem.


----------



## geeteeohguy (Feb 2, 2008)

Great news. If you ever DO pull the tank to replace the sock, clean off the retaining ring and outside of the unit first (so no grit goes into the tank), and spray the whole ring assy. with WD40. Then, use a BRASS drift to tap the ring loose (CCW). A pretty easy job. I would also recommend just replacing the sock. I have heard of a lot of problems with Re-pop sending units being the wrong resistance value, and therefore, not reliable or accurate (chinese crap). Enjoy your ride!


----------



## jimmy328 (Oct 12, 2011)

It’s no longer leaking gas; unfortunately, the engine did shut down again today on the road. I immediately popped the hood and checked the carb for fuel and sure enough very little was being ejected when I manually worked the linkage. I was only a half mile from home and it limped backed and coasted to my front yard. After cooling down 20 minutes I put it back in the garage; it’s idling now at 200 F and after one hour it did stall out but started again. It’s bizarre the engine runs semi fine in the garage but stalls/quits on the road. Perhaps fuel movement in the tank? I don’t think using heat wrap on the lines would help but I will do this anyway. I think the fuel tank should be removed, flushed, and sending unit replaced, but I’m open to suggestions.

O5GTO suggested I check for leaks between the sending unit and pump. I believe this is all one steel line. Are there possible cracks? Is there a tool or method to check for this?

Chuckha72 had a cool idea of blowing the crap off the sock with an air compressor but I would prefer to change it out.

Thanks all for the help.
Jim


----------



## geeteeohguy (Feb 2, 2008)

I've posted this before, so I'll be brief: same thing happened to me in '88 when I took my '67 GTO on vacation from CA to Yellowstone NP. In the middle of Idaho, I started having the exact same problem. In good clothes, in 100 degree heat, I'd get out and get under, disconnect the fuel line at the pump, and blow it clear with my mouth until I could hear bubbling in the tank. That would get me about 8 miles down the road at a pop. Compressed air to blow the lines at a tire shop netted the same results. Long story short, the problem was the fuel sock in the tank....it had folded up like one of those snail ended party favors, wadded up on top of itself about 6 or 8 times.....completely blocking the fuel line pick up. I ended up cutting the fuel sock off of the pickup, and 24 years later, it's still off. Fixed THAT problem! One of these days I'll get around to putting a new sock on the darn thing......


----------



## chuckha62 (Apr 5, 2010)

The reason it's doing it on the road is that your fuel demand is higher and it just can't keep up. Long term, replace the sock, but for now, try the compressed air method...


----------



## jimmy328 (Oct 12, 2011)

I’ve certainly read your post GEETEEHGUY. I suppose I could blow out the crap but I prefer to just replace the damn thing.

Chuckha62: I don’t depend on this beast for transportation. Hopefully in a week or two I can just do the job right and replace the entire fuel tank sending unit. Stay tuned (LOL). 

Thanks to all.
Jim


----------



## 05GTO (Oct 6, 2004)

Jim,

One other thing to check would be for a plugged fuel tank vent, loosen or remove the gas cap and drive the car and see if anything changes.

In my opinion the best way to gain peace of mind would be to replace the fuel tank, sending unit and vent tubing or at least drop the tank and treat the inside and flush all of the trash and rust out and also replace the sending unit sock. 

You have a rubber tube connecting the sending unit to the fuel line, from that point the steel tube is one piece until it exits under the fuel pump in front of the cross member.

Good luck,


----------



## jimmy328 (Oct 12, 2011)

*Fuel Tank Removal*

I heated up the engine, removed the gas cap and again the engine quit.

I removed the tank (easy) and coated the sending unit retainer ring with lubricant. Even with a hammer and flathead screw driver it wouldn’t turn. I may have to replace the tank. As I check out online retailers I see tanks for $120 to $180.


----------



## fasterfiero (Sep 6, 2011)

I replaced the tank in my 67 Tempest, Canadian made tank ( I believe ) I would have spent more if I thought it made a difference.... Be sure to ask if it is the same gauge metal as the original, mine is thin and although it probably won't be a problem, it still bugs the heck out of me that companies can make cheap thin crap.......


----------



## chuckha62 (Apr 5, 2010)

jimmy328 said:


> I heated up the engine, removed the gas cap and again the engine quit.
> 
> I removed the tank (easy) and coated the sending unit retainer ring with lubricant. Even with a hammer and flathead screw driver it wouldn’t turn. I may have to replace the tank. As I check out online retailers I see tanks for $120 to $180.


Spray the Bejeezeus out of it with PB Blaster. Let it sit over night, then try to remove the lock ring. If your tank is not rotted out, or too full of stuff to clean, I'd use it over a replacement, if the replacements are not up to snuff.

my $.02 worth.

Chuck


----------



## geeteeohguy (Feb 2, 2008)

Man....that is RUSTY. I've never seen one like that, being and ignorant Californian. Tanks over here still look new, for decades. X2: penetrating oil will get it done. Use a brass drift, not a screwdriver, unless you want to blow yourself up.


----------



## gjones (Oct 8, 2012)

PLEASE be careful running a shop vac around the gas tank. DO NOT EVER try to suck gas out of a tank with a shop vac. You'll be blown to smithereens. Heard tell of two Mexican mechanics in N.Y. back in the 80's that tried that little trick. They became crispy critters.


----------



## jimmy328 (Oct 12, 2011)

The PB Blaster did the job; first time I’ve heard of this product as well as X2. I thought the tank had threads to hold in the sending unit; now I see it does not and that’s good. I think the original tank will work fine once I get it cleaned up. The only problem I see with the sock is that it’s ripped in various areas. Therefore; crap in the tank could be collecting in the fuel filter that is just before the carb. This may be the culprit of the “engine quitting” problems. Obviously this sending unit needs to be replaced.


----------



## jimmy328 (Oct 12, 2011)

I received my 2nd sending unit today; the 1st one didn’t have a return line as I requested. Summit said I had to order the sending unit with the 3/8” main line witch comes with a ¼” return line; so I bought it. Now that I see it, both lines do not match the original uniy in that they are too long and make an 90 degree turn upward which would hit the trunk pan. I guess I have to bend them or cut them and somehow add a flange to help lock in the rubber tubing. 

Any suggestions please? Thank you,

Jim
See pic’s


----------



## jimmy328 (Oct 12, 2011)

Also, does the orientation of the float in the tank face downwards or upwards? I think downwards is the correct position but would like to make sure.


----------



## geeteeohguy (Feb 2, 2008)

I would A: get the exact unit and return the generic one, or B: take a tubing cutter and cut the lines and flare them at the ends so you can install the rubber hoses. The sending unit only goes in one way....it should be keyed to the top of the tank for position.


----------



## jimmy328 (Oct 12, 2011)

I buy through Summit Racing but they had this part shipped directly from OPGI (didn’t know till after payment). This is the 2nd unit the sent to me. I’m not sure an exact replica of this part even exists.


----------

