Fuel Leak at fuel line front of carb

Domano 68 · Mar 8, 2015

Got a small fuel leak. Looks to be coming from inbetween the large flange nut and where it mounts to the carb (fuel filter marking). You can see the top of the manifold where it is wet.

Tried to tighten the smaller flange nut on the left but its pretty tight. Didn't want to mess with the larger one until I educated myself here.

Is there really a filter in there? Wondering if this setup was modified and changed since an inline cant filter is located to the left if you follow the line to the left a couple of feet.

Is there an o-ring or gasket that could have gone bad? Just looking for some guidance here on what to do. Thanks in advance!

69-Pace · Mar 8, 2015

Yes there is a filter in the larger section, and there is a gasket between the body and the larger. Rochester rebuild kits or suppliers like Cliff can sell you what you need to tighten her up. http://www.cliffshighperformance.com/

If the leak is in the smaller and fuel line connector you might have an issue with the flair of the line. Some folks use liquid sealers but be careful about contaminating your fuel. COnnecting and maintaining the connection is a two wrench project - one to hold and the other to do the work.

The 69's 350/300hp engines used two filters the big can and the internal so having two is not uncommon.

TJS69 · Mar 8, 2015

Your fuel line does not look straight. Bend the line so that the flare nut will seal the line when tightened.

DEROID · Mar 8, 2015

Aircraft thread sealant also may help.

Everett#2390 · Mar 8, 2015

As suggested, straighten the fuel line into the carb and buy a Q-jet rebuild kit - used to be $8 - and use the sealing washer from the kit and store the kit for a later rebuild.

69-Pace · Mar 8, 2015

The angle of the incoming line is what we mean here by straighten the line out.

Domano 68 said:
Got a small fuel leak. Looks to be coming from inbetween the large flange nut and where it mounts to the carb (fuel filter marking). You can see the top of the manifold where it is wet.

As to the fuel line - I thought I said this last night but guess my thoughts got lost in the daylight saving time switch.

In the original factory configuration the metal fuel line would have traveled up the front of the block from the fuel pump behind the water pump and fan then for some Quadrajet equipped engines, through the "tin can" AC fuel filter - where the return line for some models looped back to the fuel rail by the fuel pump and then back to the tank - then all went over the manifold to the Quadrajet inlet with a series of bends to align the fuel line with the Q-Jet inlet.

Yours looks like it is bent up and over the valve cover. See the attached photo of a 69 Q-jet setup for reference. The severe angle may be leading to the flair of the line not sealing the nut on the two part inlet.

BPOS · Mar 8, 2015

Domano 68 · Mar 8, 2015

BPOS said:

Great stuff as always guys. Thanks for everyone's input. I understand the problem now.

Will straightening the line take some bending of the actual fuel line or just taking the fuel line off at the coupling and putting it back on and lining it up straight?

69-Pace · Mar 8, 2015

Either or both may solve your problem but I fear if the line is actually that close to the valve covers and with a high spot at top you may flash the fuel inside the line and be prone to skipping under heat condition such as idle.

Can you post a wider picture of what you have going on? The original design was at the front of the block for a reason and the lines are widely available so you can put it back stock.

Domano 68 · Mar 9, 2015

69-Pace said:
Either or both may solve your problem but I fear if the line is actually that close to the valve covers and with a high spot at top you may flash the fuel inside the line and be prone to skipping under heat condition such as idle.

Can you post a wider picture of what you have going on? The original design was at the front of the block for a reason and the lines are widely available so you can put it back stock.

Can you elaborate more on what you are referring to with the high spot and flashing?

Here is a few other pictures. Thanks for your input here! (post image icon above is not working here!)
http://i148.photobucket.com/albums/s9/dmnsmith2/IMG_2489_zpsu33tbq1e.jpg
http://i148.photobucket.com/albums/s9/dmnsmith2/IMG_2490_zps8ie4czge.jpg

Domano 68 · Mar 9, 2015

So the plan is to take the line off of the carb end and try to bend it to come in straight to the carb inlet. Any suggestions on where to bend the line or how much bend is allowed? Newbie here when it comes to fuel lines, carbs etc.

Lawrence454 · Mar 9, 2015

Domano 68 said:
So the plan is to take the line off of the carb end and try to bend it to come in straight to the carb inlet. Any suggestions on where to bend the line or how much bend is allowed? Newbie here when it comes to fuel lines, carbs etc.

I would buy a pre-bent line from a restoration company.

What car is the engine in ?

Cdminter55 · Mar 9, 2015

You may want to find a Holley or Edelbrock fuel pump which the body is adjustable. Check at Advance auto and use a $40 off coupon. (TRT41) http://shop.advanceautoparts.com/p/holley-mechanical-fuel-pump-12-327-11/6121985-P The body is adjustable to move the outlet where you need it so you won't have so many bends in the line. $50 for that pump is a steal.

69-Pace · Mar 9, 2015

Lawrence454 said:
I would buy a pre-bent line from a restoration company.

What car is the engine in ?

x2 you can bend lines yourself but its a technique and requires skill. Buying the correct line is cheap and easier.

69-Pace · Mar 9, 2015

Domano 68 said:
Can you elaborate more on what you are referring to with the high spot and flashing?

The line currently looks like it is running over the valve cover higher than the fuel inlet. Like a "still" the fuel could flash its state to vapor due to the heat off the covers then take time to condense back to liquid.

Thats why I asked for a better over all picture to figure out how this ride is plumbed.

TJS69 · Mar 9, 2015

OK, the reason it is leaking is because the line has too much pressure on it, and they just tightened up the connection at the carburetor and hoped it would seal. The easiest fix would be to hold the line straight and "pull" on it as you retighten the connection so it goes in straight.

Another way would be option #1 in the photo. Cut the line at the two red lines, slide some rubber fuel line over the ends of the tube and tighten with hose clamps. The hose represented in crooked white line. Note: You will still need to "redo" the connection at the carburetor so it is straight.

Option #2 - Don't have a tubing cutter ? Remove the connection at carburetor and install hose fitting. (use teflon tape) Use hose clamp to insure that rubber fuel line is secure. Remove compression union (splice) at top of valve cover including the compression ring from the line and push rubber hose over the fuel line (if you can get the hose over the compression ring on the line, you can leave it on the tubing) and clamp it with a hose clamp.

You will want to push the tubing over towards the water pump so the line isn't on the valve cover. (light green arrow in picture)

Use a good quality 1/4" fuel line (I would use NAPA etc.) NOT just rubber hose !

Domano 68 · Mar 9, 2015

69-Pace said:
x2 you can bend lines yourself but its a technique and requires skill. Buying the correct line is cheap and easier.

The engine is out of a 69 Impala. Going the new line route, I assume it would be one piece ( one line) going from the pump to the carb?

TJS69 · Mar 10, 2015

Single fuel line on the frame usually meant a Holley carburetor. Dual Fuel lines on the frame meant the quadrajet, with a return line at the fuel pump.

This should be what you need.

http://www.rickscamaros.com/camaro-...l-pump-to-carburetor-steel-327-and-350ci-4-barrel-carburetor-3-8-1967-1969.html

BPOS · Mar 10, 2015

http://inlinetube.com/Preformed Lines/Camaro/68 Camaro/Engine lines/CCE6802.htm

Domano 68 · Mar 10, 2015

:beers:

Again, much thanks!

Fuel Leak at fuel line front of carb

Domano 68

69-Pace

TJS69

DEROID

Everett#2390

69-Pace

Attachments

BPOS

Domano 68

69-Pace

Domano 68

Domano 68

Lawrence454

Cdminter55

69-Pace

69-Pace

TJS69

Domano 68

TJS69

BPOS

Domano 68

Top Contributors this Month

Recommended Communities