fuel line replacement...

[toolboy62]

OK, so the shop that my car is at finally called me. I have to say the guy that I talked to sounded really knowledgeable and motivated to get my car right, and I appreciate that. One thing he brought up concerns me though. He mentioned that the hose between the hard fuel line and the fuel pressure damper was replaced with a piece of regular high pressure hose with hose clamps on it. This is absolutely correct; it *was* replaced as it was leaking when I first bought the car. Another shop did the "fix" and I thought it was OK although they used worm drive clamps... I meant to replace it eventually with proper high pressure clamps and a new piece of hose, but I never got around to it. It's been fine since, but the guy seems really paranoid about engine fires... apparently he had one repaired like this go up in the shop and he's recommending that I replace it properly. The only problem is, his idea of "properly" involves factory replacement parts, at a cost incl. labor of about $1200.

My question is this: what kind of fitting is required to connect to the fuel pressure damper? I have no fear of fabrication and flaring, and I'd be willing to offer as an alternative that I could fabricate a line from stainless braided aircraft tubing and flare the end of the hard line for an AN tube nut, if this is a practical alternative. Would dress up the engine compartment, probably be of higher quality than the factory parts, and a HELL of a lot cheaper than replacing everything back to the tank when all that was ever bad was 2-3 feet of hose.

I am willing to do something to replace this hose to keep the guy happy because he does seem like a good mechanic and it's worthwhile to maintain good relations with a good mechanic. (they are hard to find. If the guy thinks I'm a cheapskate you know he won't do good work or even be willing to work on the car anymore.) But I can't see spending $1200 on a car that's worth maybe $3500 on a good day. Financially it would make sense to just drive it and carry a fire extinguisher; if it burns well then just buy another car. Of course, being a 944, that would be sad, but still...

nate

[Techno Duck]

$1200 is insane.

You can get a replacement hose from Rennbay with the proper fittings for about $110. Taking the rail off and changing the hose should take roughly 1 hour of work.

I would however be happy to drive down and change that hose for you for $1200.

I just looked it up, the OEM line is $90 at Pelican. The Rennbay line uses some nice quality aeroquip hoses and routes the line differently, removing the bend which typically causes the crack in the rubber.

[toolboy62]

I've seen the Rennbay kit, I have to admit that I don't much like the push-on fitting however. What about using that with Oetiker clamps? That'd probably satisfy *me* but I don't have any handbooks listing max pressure ratings of the hose, fittings, or clamps used in the kit.

Yes, I am a little anal retentive myself... If I'm going to spend significant amounts of money (and in my world, that's "more than $20") on a fix, I want it to be damn correct.

nate

[EMBPilot]

Nate,
Im watching this thread closely as i recently changed my lines over to the rennbay lines and am completely paranoid about it. PLEASE PLEASE continue to post here what you come up with and what your mechanic has to say. there are lots of ideas around here floating around about all sorts of solutions.

I used the rennbay line from the damper to the fuel rail and switched back to the OEM line heres why. The rennbay line from the damper to the rail is built to be REBUILDLABLE, so it uses a compression fitting that in turn screws to a fitting to attach it to the rubber line. i felt that, two inline fittings at one connection was asking for trouble, mine happened to have a gas smell i think one of the fittings were loose. so i switched it to a new OEM jumper, that has one fitting at each connection and the rest is crimped.

now for the two lines over the exhaust manifold, the return line comes from the factory w/ a fuel line clamp that attaches it to the fuel regulator, so im good with that. The supply line i have on my car is attached with a fuel line clamp over the factory barb on the hard line at the fender. it connects at the damper with the screw on compression fitting. seems to be holding well and doesnt smell or leak. I think its fine for now...


theres also this guy, Vic @ Pauer Tuning LLC

pauerzone@cox.net he is an aircraft mechanic and makes these SS lines himself they are similar to the Lindsey set

he can be found on Rennlist.

The two above sets attach about 4" INSIDE the fender, you cut back the hard lines and attach these heavy duty compression fittings onto the lines and secure the SS lines on that way. Then cover the SS lines with a thermal cover.

two schools of thought here. Ive had one guy explain to me that compression fittings should NOT be on anything that can vibrate (like a car), and they are likey to vibrate loose, however he did admit after seeing the quality of the compression fittings that "they should be okay but..." he felt that the rubber lines over the factory barbs in the engine compartment with the fuel hose clamps were adequate given the fuel pressure. (around 36 PSI)

the other school of thought, and i think i lean towards this one is....
use the compression fittings in the fender, they will 1) withstand the high pressure fuel going to the damper and hold up very securely. if there is ever god forbid a problem it will occur inside the wheel fender and not spray all over the hot exhaust manifold. and 2) that the rubber lines are a bad idea because the temp in that area of the compartment is too hot and 3) the pressure is too high on the delivery side to safely use the fuel line clamps that are most commonly found on carburated cars.

Come the spring i am going to switch over to the Pauer Tuning system.

I wrote a lot here, sorry about that, im new to most of this and am just a guy that wants to do the job right and not have a nuked 944. The guys here are your BIGGEST ASSET!

-- a shout out to Jon, Tom and Hugh --




note, i no longer use the damper to rail jumper shown here.

please keep us in the loop with what you do!

[schwank]

My car looks exactly like Kevin's, fuel lines, vacuum, and all. The factory lines are available if you want to stay OEM, 944online has them for a fair price. Mine went 20 years.... But I went with the rennbay kit and I'm happy. They are burly. I cut my supply lines back into the wheel well and used two worm clamps ON EACH LINE to attach. So far I've seen no reason to freak, but that's why I put the fuel outside the engine bay. I see people reusing the stock compression fittings after they pry them off the original 20 year old lines, then put them on new lines right over the exhaust headers. How people think the rennbay lines are sketch but are ok with that, I have no clue.

Like jon says (listen to that man folks!), 1200 is INSANE. If you are a total noob, like never changed an oil filter kinda noob, you could do this job with 2 wrenches and maybe an hour, if you are very particular.

Save $1000 cash, spend 50 on nice tools, buy the lines on the net and do it yourself.

[SoCal Driver]

The return line from the fuel rail (regulator) can use clamps.

The feed line should have swedged tubing fittings to the hard line and proper high pressure hose with crimped flared fittings to the fuel damper. Steel lines are preferred between the damper and the rail and the rail and the regulator.

You will also want to support the flex lines just before they connect to the fuel rail. Having these lines vibrate can cause cracking of the fuel rail around the damper and regulator mounting brackets where they weld to the rail proper.

[toolboy62]

Like jon says (listen to that man folks!), 1200 is INSANE. If you are a total noob, like never changed an oil filter kinda noob, you could do this job with 2 wrenches and maybe an hour, if you are very particular.

I agree it's insane... but the way the guy was talking it sounded like to use the factory line I needed to drop part of the rear suspension because the fuel line went over some hard bits? Or does my BS detector need to be calibrated? ('cause it didn't go off - I've seen enough maintenance intensive jobs on cars that nothing really surprises me anymore.)

I appreciate the link to the Lindsey lines but I see they use a compression fitting on the hard line, I'd really feel better with some kind of flare fitting...

I do realize that in the grand scheme of things we're ALL being paranoid, and really, a new piece of high pressure FLAPS fuel line and a double hose clamp on each end (the high pressure, smooth kind of course) is likely safer than a 20 year old factory piece.

nate

[toolboy62]

just took a closer look at those pics... so it appears that the hose in the Rennbay kit is Aeroquip - that is a good thing. Also appears that it is 3/8" diameter, so why not just slide an AN tube nut and ferrule on there and flare it then use an AN fitting instead of a hose clamp? What would the correct size be anyway? 6AN? I think?

nate

(I wish there was an online tutorial in this stuff, the Pegasus Racing catalog assumes that you have some familiarity with this stuff and the last time I made my own fuel line for anything it terminated at a Carter AFB...)

[Razorback1980]

Is he talking about the hard lines that run from the fuel tank forward or just the line that connects the dampner to the hard return line? Sounds like he wants to replace the whole line from the tank to the fender well. I must be misunderstanding.

[toolboy62]

yup, that is exactly what he wants to do, but IMHO that is not necessary since the steel is in good shape...

nate

[Razorback1980]

Unless there was water stored in it and it rusted, I can't see a reason why you would ever replace it either. Sounds like overkill to me. I would have him pass on that project and take care of it later myself.

[EMBPilot]

Originally posted by SoCal Driver
swedged tubing fittings

whats a swedge fitting?

[toolboy62]

swage = factory style fitting with a crimp collar

nate

[SoCal Driver]

There are fittings that will compress onto the OD of the steel tubing coming from the fuel tank/pump. These crimp onto the tubing providing a mechanical lock. Called swedge or swag. Check out http://www.swagelok.com/

One side of the fitting swags (swedges) onto the tubing with the other end of the fitting having the flair for the high pressure tubing or hose. These are used in high pressure hydraulic applications like back hoes and other construction equipment. I've used similar in saturated steam manifolds for many years.

[Gear Dog]

I put in the Lindsey racing lines and it was a pretty easy fix. This is an old shot, I cleaned the gas/varnish that was pooled up in the shock tower

[EMBPilot]

I want to mention something i discovered today. After a pretty long conversation with Vic at Pauer Tuning.

I really wish i purchased his kit first, his name JUST ISNT out there like the lindsey name is. His kit is $140 and WAS the first stainless steel kit with heavy duty compression and AN37 adapter fittings made for the 944. his kit was so nice, Lindsey COPIED HIS PRODUCT.

i come from a family of small time designers/inventors. My dad holds HUNDREDS of successful patents in the toy industry and my brother holds a single patent in the fencing industry. so this really strikes home with me. because i know personally how much it sucks to get walked on, and then have someone else take credit for something that is not theirs.

His support is second to none, i didnt even buy a kit from the guy and we were emailing back and forth throughout the day. he had every right to tell me to go pound sand as i purchased his kit from a competitor.

If your going to upgrade your fuel lines, the Pauer Tuning kit is the way to go. Id venture to say its of higher quality than the Lindsey kit based on his background as an aircraft mechanic and his PERSONAL support.

I thought to flare the hard lines in the wheel well and use a double flare fitting, however the tool to put the flare on the hard line is about 2bills and it is also an overkill. The compression fitting supplied with Vics kit will withstand FOUR times the pressure of the 951 fuel system.

In fact, after typing this, IM GOING to order his kit. i dunno what im gonna do with the lindsey kit, ebay, deep six it... i dunno, but i'll feel a lot better using the guy who did it the right way first.

[nynor]

my two cents, because i can't help it...

i took my car in with a fuel leak at the fuel pump. i determined that it was the hose there was split. not wanting to mess with it, i took it to the shop. i called them three days later and they said they were working on it still. i couldn't figure it out. then after a week, i called and insisted they tell me wtf was going on. turns out, they replaced the whole fuel line, the return lines, the fuel tube to fuel tank. this entailed dropping the transaxle and fuel tank. i nearly freaked. the labor alone was $1200.

the story does have a silver lining: no more fuel smell in the car whatsoever. the lines are new, the filter is new, and they did good work.

however, i could have purchased my own LIFT for $1K and done the work myself. total bill was in the neighborhood of $1800.

[Razorback1980]

Ouch! I would think they would call you with an estimate before they run up a bill like that. I would have been ticked.

[nynor]

yeah, i wasn't very happy. i thought an hour or so labor and some high pressure hose. my wife was ANGRY!

[toolboy62]

I don't know why I just like the idea of using a flare over a compression fitting. probably because my grandfather was a tube fitter and I must have unconsciously picked up a few things from him. Anyway a 45 degree double flare tool can be had for about $40 or so, I have one as well as an ISO flare tool.

Funny thing is, though, I can't seem to find any common use of 37 degree AN flares on plain old steel tubing anymore! Are my web search skills not so good, or are they really obsolete? Are the compression fittings really better?

I will have to drop this Vic guy a note and get his thoughts on my ideas. Sounds like he would be a good source for parts, anyway.

nate