Replacing 4AF fuel lines

[Ghostyman]

I'm going to replace the fuel lines on my 20 year old 4AF. The existing ones don't leak but they are riddled with cracks and won't last too much longer.

I've acquired 10' of 1/4" ID fuel line. It's some transparent red stuff. Not quite as thick as the OEM line so I couldn't reuse the stock clips (I actually zip-tied it on).

It was technically listed as fuel line for "SNOWMOBILES, BOATS, PERSONAL WATERCRAFT, GO-KARTS, MINI BIKES, LAWN MOWERS, MOTORCYCLES, GOLF CARTS, JET SKIS, POCKET ROCKET, SCOOTERS, AND ANYTHING WITH 1/4" FUEL LINE"... basically everything except for a car.

So far I've only replaced one section (filter to pump) just to make sure it holds up okay. A week and a couple hundred miles later, no problems. (Okay, I lied... I just went back outside and replaced the hard line to filter hose.)

Any potential problems anyone sees with this? It is supposed to withstand -65 to 220f temperatures.

Pictures:

[Ghostyman]

Also, can anyone confirm that stock fuel pressure is 6psi?

[kathyricks]

The factory original hoses have METRIC inside and outside diameters. It's a Japanese car so everything is metric. So either buy Toyota hoses from a Toyota dealer or carry a fire extinguisher rated for gasoline fires.

[Ghostyman]

Originally Posted by kathyricks

The factory original hoses have METRIC inside and outside diameters. It's a Japanese car so everything is metric. So either buy Toyota hoses from a Toyota dealer or carry a fire extinguisher rated for gasoline fires.

Thanks for your know-it-all response.

Do you know what those metric diameters are? I do... because I'm not completely stupid. The fuel pump uses a 6.2mm inlet and outlet. I know this because I measured it with my digital calipers. Because, once again, I'm not completely stupid and I understand that imported cars use metric measurements. Do you know what 6.2mm is in inches? It's 0.24... want to tell me how close that is to one quarter inch?

And just so you can't head me off at the pass: I know the return line is smaller. It's 4.8mm ... 3/16" ID fuel line happens to be 4.76mm ID.

Golly gee. Do you think they're the same thing?

Lastly, I carry a fire extinguisher in every car I own, along with a first aid kit and a change of clothes. There's no reason not to and every reason to.

Thanks for the feedback.

[kathyricks]

I found out the hard way the rubber of an auto parts store fuel hose is so low in quality it will crack and leak within 2 years instead of 20+ years like Toyota fuel hose. And the fact that it doesn't have precise fitting metric inside and outside diameters aggravates this tendency to crack and leak when installed in a Japanese car.

Ditto vacuum hose. Toyota vacuum hose will also last 20+ years. It's sold in 2 foot lengths for about two bucks part number 90999-92003. $20 worth will do an entire 4A-F engine compartment, but I'm not changing mine yet because my hoses are still not cracking or leaking.

[Ghostyman]

Sigh... indoctrination much?

Look, there is nothing magical about Toyota vacuum or fuel hose. I replaced rubber vacuum hoses with silicon for the same price. Silicon is a better vacuum hose material than rubber. And I get to let my inner ricer out and color code stuff.

Ditto the fuel line. There's nothing different about the gas that Toyota engines use. You're worried about a nominal one hundredth of an inch in diameter. That's well within manufacturing tolerances for rubber hose. They're the same hose. Why do you think the Japanese chose 6.2mm? Because it's a nice, round number?

Are you totally sure that all auto parts store fuel line will crack within 2 years? That's a bit of a bold statement. Please explain the magic process that makes Toyota fuel lines different.

EDIT: And why do you keep referring to the OD of hose? What does that have to do with anything? Seriously, please explain.

[Flashmn]

rubber parts in general dont last 20+ years with the abuse they suffer in an automotive environment....They can, but... they're gonna be crispy and crappy.
Toyota doesnt have their own special rubber tree which they make their hoses from, they buy them from a supplier, such as gates, sumitomo, etc.

Outside diameter has little use on fuel hoses, if the hose fits over the barb snuggly its fine.

[kathyricks]

Originally Posted by Ghostyman

Please explain the magic process that makes Toyota fuel lines different.
EDIT: And why do you keep referring to the OD of hose? What does that have to do with anything? Seriously, please explain.

OD impacts the bendability and crackability of the hose over time. Like you, I don't know what Toyota's trade secrets are in regard to hose formulation. I just know that if Toyota decided to use Autozone or NAPA fuel hose, alot of it's cars would go up in smoke within 5 years due to fuel leaks and the company would be sued into oblivion. I've seen Autozone standard fuel hose crack and leak in 8 months, though i suppose if you use hose rated for fuel injection service it would last longer, but not 20-35 years like Toyota fuel hose.

Similar analogy: Rice boys commonly install polyurethane suspension bushings for tighter handling control. But guess what happens to those 'superior' bushings in 5-10 years? They shatter and the car can barely be controlled. This happened to the list owner of the Classic Celica list this past week, fortunately at low speed so he is still alive (but shaken). He installed the poly bushings 8 years ago.

[eage8]

Originally Posted by Ghostyman

Also, can anyone confirm that stock fuel pressure is 6psi?

I looked in my FSM when I got my weber, and it's 6 psi.

I hate to say this but you should probably be fine with zip ties I would probably get some sort of hose clamps though...

other than that, it looks pretty good. clear isn't a bad idea, so you can diagnose if you have fuel in the lines

[eage8]

Originally Posted by kathyricks

OD impacts the bendability and crackability of the hose over time. Like you, I don't know what Toyota's trade secrets are in regard to hose formulation. I just know that if Toyota decided to use Autozone or NAPA fuel hose, alot of it's cars would go up in smoke within 5 years due to fuel leaks and the company would be sued into oblivion. I've seen Autozone standard fuel hose crack and leak in 8 months, though i suppose if you use hose rated for fuel injection service it would last longer, but not 20-35 years like Toyota fuel hose.

Similar analogy: Rice boys commonly install polyurethane suspension bushings for tighter handling control. But guess what happens to those 'superior' bushings in 5-10 years? They shatter and the car can barely be controlled. This happened to the list owner of the Classic Celica list this past week, fortunately at low speed so he is still alive (but shaken). He installed the poly bushings 8 years ago.

I've had autozone hoses on my rx-7 for about 4 years.

a turbo rotary is probably the harshest environment I can think of for rubber and they haven't cracked at all.

and I also don't see how a poly bushing can "shatter".... it's probably from not re-greasing them ever...

[TonkaTom]

Looks fine, just inspect them every once in a while (you probably already do that), and because they aren't as thick don't drive to the north pole, you might have problems.

Edit: At -65 you might be covered...

[kathyricks]

Originally Posted by eage8

and I also don't see how a poly bushing can "shatter".... it's probably from not re-greasing them ever...

Subject: [Classic-Celica] my car tried to kill me
Date: Thu, 19 Mar 2009 06:04:56 -0000
From: "Wayne Stephenson" <stepho@iinet.net.au>
Reply-To:

I had a problem that suddenly appeared when going around corners - the car would go around normally to about the half way point and then suddenly dart further in.

Took it to the tyre shop for alignment. The tyre guy noticed very bad camber on one wheel, fixed that and took it for a test drive. He came back very shaken, saying it tried to throw him off the road.

Further inspection showed the polyurethane bushes I'd fitted 8 years ago had become brittle and had left the room. This left about +/- 1cm wriggle room for the main pivot of the lower control arm - hence the sudden darting in corners.

- Stepho

[79Corona]

You know in 34 years of driving I've never had a fuel fire in any car I've owned? Quite puzzling I say.

[Ghostyman]

Originally Posted by eage8

I looked in my FSM when I got my weber, and it's 6 psi.

I hate to say this but you should probably be fine with zip ties I would probably get some sort of hose clamps though...

other than that, it looks pretty good. clear isn't a bad idea, so you can diagnose if you have fuel in the lines

Thanks for the pressure confirmation. I specifically went with clear fuel line so I can visually make sure that fuel is flowing. For the same reason, I'm replacing at least one of my coolant hoses with a completely clear one so I can quickly see the condition of the coolant. Blue vacuum hose just made sense to balance out the color scheme.

I even put the zip ties on when the engine was warm so the fuel line was a little softer and I was able to make sure the ties bit well. I'll put some hose clamps on at least a couple of the fittings just for ease of removal.

Originally Posted by Flashmn

rubber parts in general dont last 20+ years with the abuse they suffer in an automotive environment....They can, but... they're gonna be crispy and crappy.
Toyota doesnt have their own special rubber tree which they make their hoses from, they buy them from a supplier, such as gates, sumitomo, etc.

Outside diameter has little use on fuel hoses, if the hose fits over the barb snuggly its fine.

I'm sorry but you're wrong. I did some vague, unspecified research and found out that Toyota makes their hoses out of unicorn skin and it actually gets stronger as it ages. The entire engine is also coated with a magic treatment that causes it to spontaneously burst into flames if it detects a non-OEM part. Don't ask for more details because Toyota will send ninjas to your house.

[Ghostyman]

Originally Posted by kathyricks

OD impacts the bendability and crackability of the hose over time.

Yeah, and it's gotta have a metric OD, right? Have you looked at the path the fuel line takes? No sharp turns.

@ "crackability"

Originally Posted by kathyricks

Like you, I don't know what Toyota's trade secrets are in regard to hose formulation.

Actually, I do know. It goes a'little somethin' like this:

- write up specs for fuel hose
- evaluate offerings from prospective suppliers
- get bids
- pick a supplier*
- watch the spools of 1/4" (oops, 6.2mm) fuel line roll in

* Somewhere in there, someone embezzles some money and steers the contract towards his brother-in-law's rubber factory.

Originally Posted by kathyricks

I just know that if Toyota decided to use Autozone or NAPA fuel hose, alot of it's cars would go up in smoke within 5 years due to fuel leaks and the company would be sued into oblivion.

Mad libs: "I just know that if anyone decided to use Autozone or NAPA fuel hose, alot of America's cars would go up in smoke within 5 years due to fuel leaks and the company would be sued into oblivion."

Why don't they get sued?

Originally Posted by kathyricks

I've seen Autozone standard fuel hose crack and leak in 8 months, though i suppose if you use hose rated for fuel injection service it would last longer, but not 20-35 years like Toyota fuel hose.

Let me show you 20 year old "Toyota" fuel line and you can tell me if you consider that "lasting" for 20 years, let alone having another 15 years in it's life. And this is a California car that doesn't see cold weather -- it would tend to have longer lasting hoses due to climate.



I consider this unsafe... and I've got some pretty liberal definitions of "safe".

Originally Posted by kathyricks

Similar analogy: Rice boys commonly install polyurethane suspension bushings for tighter handling control. But guess what happens to those 'superior' bushings in 5-10 years? They shatter and the car can barely be controlled. This happened to the list owner of the Classic Celica list this past week, fortunately at low speed so he is still alive (but shaken). He installed the poly bushings 8 years ago.

Who? Wha? Seriously?

Not enough time in the day to respond to all this at length but I don't expect you to admit you were wrong in public so we'll just call it a night.


Hey, this is fun! Thanks for coming on my thread!