Fuel Lines: Does this sound right?

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Julie P. - 20 Nov 2005 23:06 GMT

Sorry to post yet again today, but my car needs a lot of help. :)

I went to measure the outside diameter of my three fuel lines today with a
1" micrometer. At least one line is leaking. They are all very rusty near
the rear. I need to replace about 60" worth of each line.

Here are my measurements:

Fuel Tank to TBI Unit: 0.4025"
TBI Unit to Fuel Tank: 0.3016"
Evaporative Canister to Fuel Tank: 0.2063"

So I need to find what size of line to buy.

Does this sound right:

Fuel Tank to TBI Unit: 0.4025" -- USE 3/8"
TBI Unit to Fuel Tank: 0.3016" -- USE 5/16"
Evaporative Canister to Fuel Tank: 0.2063" -- USE 3/16"

My GM shop manual does not specify size, or even type of flare used (I
assume it is ISO metric bubble flare, since that is how it is on my 3/16"
brake lines).

Also, before entering the tank, my three lines go to hoses, and then back to
a metal line again. They go right into the tank as metal lines, but it is
hard to see exactly. I think these metal lines are built right into the
tank. They are rusty there, so I guess I will have to replace the tank now
too then? And since I have the tank off, I might as well do the fuel pump.

Thanks for any help!

Julie

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Shep - 20 Nov 2005 23:54 GMT

Julie, due respect, if you are going to tackle these jobs, you should get a
subscription to say Alldata.com ,has a complete on line manual for 24.95.
Your lines sound right double check the flares, may be just double flares,
The tank itself won't need replacement, just the pick up/bracket for the
pump where the lines are rusted. Again, try and remember to post what car
this is.

> Sorry to post yet again today, but my car needs a lot of help. :)
>
[quoted text clipped - 29 lines]
>
> Julie

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Julie P. - 21 Nov 2005 02:19 GMT

> Julie, due respect, if you are going to tackle these jobs, you should get
> a subscription to say Alldata.com ,has a complete on line manual for
> 24.95.

Thank you Shep. I am considering this. But I do have the official GM shop
manual.

> Your lines sound right double check the flares, may be just double flares,

Ok, I hope so. The manual says: "The flare used on these fuel pipes is not
compatible with the flare used on normal fuel pipes."

I know for a fact my brake lines use bubble flare, ISO metric, and not
double lap, which sucks, since the bubble flaring tool is much more
expensive than the double lap flare tool.

> The tank itself won't need replacement, just the pick up/bracket for the
> pump where the lines are rusted. Again, try and remember to post what car
> this is.

Sorry! Yes, it is a 91 Chevy Cavalier 2.2 liter.

Julie

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Mike Romain - 21 Nov 2005 00:20 GMT

Wow, I took the body off the frame for my rebuild.....
http://www.imagestation.com/album/?id=4292105877

Made running all the lines 'soo' much easier....
;-)

You are correct I believe in your size estimates.

Where the hoses meet the steel at the tank will be a tank fitting.
Either the pump base for the TBI lines or a check valve for the canister
line. These tank fittings remove from the tank usually.

Normally you just want to deburr the new steel lines. They don't use
fitting ends, but the slightest burr and it will eat through the hoses.

Make sure you specify 'gas' line when you buy the flexible hoses.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/index.html?id=2120343242
(More Off Road album links at bottom of the view page)

> Sorry to post yet again today, but my car needs a lot of help. :)
>
[quoted text clipped - 29 lines]
>
> Julie

Reply to this Message

Julie P. - 21 Nov 2005 02:12 GMT

> Wow, I took the body off the frame for my rebuild.....
> http://www.imagestation.com/album/?id=4292105877
>
> Made running all the lines 'soo' much easier....
> ;-)

Very nice pic. At least your body come off though. And it look like you have
a garage to work in, which is nice. :)

> You are correct I believe in your size estimates.
>
> Where the hoses meet the steel at the tank will be a tank fitting.
> Either the pump base for the TBI lines or a check valve for the canister
> line. These tank fittings remove from the tank usually.

Ok, I hope these are regular flare nuts, and that the fitting is not frozen
to the line, like with my brake lines. I know there are flare nuts at both
ends where the line enters the fuel filter, and also where the fuel pump
line enters the hose before the fuel tank. And also at the other end too,
where they enter the TBI unit.

> Normally you just want to deburr the new steel lines. They don't use
> fitting ends, but the slightest burr and it will eat through the hoses.

Re the deburring, I am always scared there will be metal slivers left in the
line, after I use a needle file on them. I had to use a needle file in order
to get the flaring tool to fit in my existing brake lines where I cut them
(I only replaced half the brake line, since the front end was still good).
But I suppose I could just blow on one end for new line.

> Make sure you specify 'gas' line when you buy the flexible hoses.

Got it! That's what the GM manual says too. It says use "fluoroelastomer".
And the line must be brazed seamless steel tubing needs to meeting GM
specification 124M. The good news is I am allowed to use fuel hose to
replace part of the vapor fuel line, at least, so long as it is not longer
than 10" at a time.

And O-rings need to be brown, not black, and called "Viton(R)".

Julie

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Julie P. - 21 Nov 2005 02:52 GMT

> Got it! That's what the GM manual says too. It says use "fluoroelastomer".
> And the line must be brazed seamless steel tubing needs to meeting GM
> specification 124M. The good news is I am allowed to use fuel hose to
> replace part of the vapor fuel line, at least, so long as it is not longer
> than 10" at a time.

Also, I am allowed to replace up to 6" of faulty fuel line with fuel hose!
This is great, especially for area where the line bends! I won't have to
bend them now with springs or the bending tool.

It just seems so weird they would allow this though, due to the pressures
involved and risk of a leak or burst.

Julie

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Mike Romain - 21 Nov 2005 03:02 GMT

> > Got it! That's what the GM manual says too. It says use "fluoroelastomer".
> > And the line must be brazed seamless steel tubing needs to meeting GM
[quoted text clipped - 10 lines]
>
> Julie

Ahh, I was off then, you do have some flare fittings too. I was just
thinking the steel to flex line connections. You need good clamps for
that.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/index.html?id=2120343242
(More Off Road album links at bottom of the view page)

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Shep - 21 Nov 2005 12:29 GMT

Julie there are 2 types of rubber fuel lines, one especially for high
presuure fuel systems that will hold 85 psi.

>> Got it! That's what the GM manual says too. It says use
>> "fluoroelastomer". And the line must be brazed seamless steel tubing
[quoted text clipped - 10 lines]
>
> Julie

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