rockatansky

Hello. Right now I have my tank in the garage floor and have been doing some cleaning and other repairs there. One of the things is to replace soft lines at my 1980 CIS 928.

I bought some good quality lines from Greg Brown. I asked Greg, but I'm sure he is pretty busy right now to help, so I'm asking the forum for advise about torque values before breaking anything.

Attached is a picture with one of the connectors. My intention is to:

- unscrew 'A' completely away from the hose.
- screw it to the rigid line in the car. (Torque value?)
- Then screw the 'C' to the 'A' connector already in the car. (Torque value?).

This way I think I will not get 'A' loose when tightening 'C'...

The hose came with this label attached in thread at the space 'B'. "Adaptor not Tight (not sure if it says tight)". They seem aluminum connectors so I don't want to over-tighten anything. Any advice will be greatly welcome.

I think I will borrow an open-end torque wrench so I could keep torque values controlled so any values will really help.

ps.- In the near future I will post a video of the whole process removing the tank, cleaning, fuel sender repair, changing lines...

NoVector

I don't know the torque values. But rather than borrowing an open-end torque wrench, you could buy a set of crowfoot wrenches (and use on your torque wrench). Can't upload a picture, but here's a link to what they look like. http://www.jrwebster.co.uk/assets/im...nches/F108.jpg

Leon Speed

I'd say the torque value is 'nice and tight' but not too tight. In other words, tighten with feeling. Light on the wrench, not heavy. Check for leaks and tighten a bit more if needed.

jcorenman

Joaquin,

When I asked Greg this question, the answer was "snug, but not too tight". These are aluminum flare fittings, and don't need much pressure to seal-- only enough to make sure that they are secure, and will not loosen. If over-tightened then the "female" side of the fitting distorts and jams the threads. You see this often with the ball-flare fittings on the stock pressure-regulators and dampers-- they are sometimes hard to disconnect because the PO over-tightened them and distorted the female fitting.

Greg said these are always hand-tightened with short wrenches-- handles of only a few inches-- and aluminum wrenches are sold to use on the aluminum fittings. I use normal end-wrenches but grip them only with a couple of fingers near the fitting.

Also, always counter-hold these fittings: Use two wrenches, one on each fitting, so that the force goes only to the part that you want to tighten or loosen.

So yes, remove fitting "A" and attach it to the hard-line: One wrench on the steel male-part on the hard-line, a second wrench on fitting "A". Then attach fitting "C" loosely, and when you have the hose-routing correct then tighten fitting "C" with one wrench on fitting "C" and a second wrench on fitting "A".

Greg also suggested a very light coat of anti-seize paste on the aluminum fittings-- on the male threads only. This helps the fittings thread together but don't put any paste inside the fitting, on the flare.

I hope this makes sense.

Edit: What Aryan said ^^^

Cheers, Jim

rockatansky

I already have the crowfoots in mind, and now they are on the way home. A box with 15 extensions, great idea, great tool. Also a short torque wrench that I will use often. My long torque wrenches are too long for many tasks and I'm always missing a short one for low torque values, so this is the time to get one. Is also on the way.

Ok Aryan, I will set my wrench at 'nice and tight but not too tight' position

makes sense. With this information I think I can visualize the force needed. More worried on over-tighten that letting it loose, but I will try and of course check for leaks with the fuel pump bridged.

Thanks a lot Jim for your detailed comments. Well, I think I have a lot of information on how to proceed. Some connectors will be easy to 'feel' but others, like those entering and leaving the engine bay from the botton... counterholding... through a small hole with both arms (sssh*t), will be more delicate. I'm thinking now that I will tight before some easy access hoses and check there the value I set by climbing the torque wrench with one NM meter at a time, when the connector moves a bit, I will know the force I applied by feeling, then set this same value on the others... it could work.

Thanks also for the advice on anti-seize. This hoses will survive me (thanks Greg) but the next owner at 2050 will really appreciate.

I will let you know how it goes. Tomorrow I will be getting the tank back in place and probably in a couple of days I will be changing the other lines. Thanks!.

Rob Edwards

Most important step in assessing fuel hose connection tightness is the last one, where you jumper the fuel pump and run around the engine compartment with a bare finger, looking and feeling for any seepage at any of the connections you just tightened.

dr bob

I did this with Rob when he worked on my car with me on the intake refresh. There was one leak almost too small to detect with fingers. A sniff of the contaminated finger confirmed the leak location. Of course it wasn' at any of the obvious and easily-accessible connections. Anyway, your nose is your third-sense helper on this task.

Mrmerlin

dont use a torque wrench to tighten any of the fuel line fittings,
thats the quick way to trash the connectors.
with steel you can snug them a bit more than the aluminum parts,
BUT just past snug is usually enough.

NOTE this means no ham fisted no nothing touching the connectors with the wrenches

GregBBRD

Yes, that note does say "Adaptor not tight". Sorry, too many years of writing stuff very fast.

That note is on there, because someone complained that I didn't tighten the adaptor onto the hose and it leaked. I always though that people would install the adaptor and then the hose, but what the heck...I now put a note on every one. Never thought about no one being able to read it...

I've been baffled by the question about how much torque. I've never seen a torque specification for a fuel line...much less an AN fuel line fitting. I've certainly never torqued one...one of the few things I do not torque.

"Tight....not over tight" sounds good to me. I'm guessing about 40 ft. lbs. for the adaptor to the steel fuel line and 30 ft. lbs. for the fuel line to the adaptor.

Let me know what you find out.

Mrmerlin

I could just envision a broken torque wrench that didnt click till it was way over the selected torque,
now the fitting coupler is trash.. a good set of hands is needed to tighten the coupling

Leon Speed

You said it much better

rockatansky

Ok. Rob, I will check every new connection more than once when I jump the pump first.

Bob, good advice using the nose. I will.

Greg, thanks. I didn't know fuel lines never use a torque value. I suppose they ask you many times because for experts is easy to have a feeling on every bolt but for people starting on this like me, it's better to know the ft-lbs before breaking something. I will do my best to feel the force (as luke did) before using the torque wrench on this. I will let you know how it went...

Mrmerlin, I knew also about one guy that after changing the oil of his bike, used nice snap-on torque wrench, that was so nice that used a digital display instead of clicks to set the force and a beep when that force was reached. Batteries in the wrench got dead when he was already tightening the bolt and... never beep...

Thanks guys, I have enough information to get on the task This afternoon I have already installed the tank back. As soon as I can I will do the lines and let you know.

GregBBRD

The Snap-on people should use those tools a bit, before they go to market. They are nice, but the battery cover, being threaded with a right hand thread naturally loosens as you pull. Common to suddenly not have power to that little computer....especially on the 1/2" drive unit when tightening big hardware at higher torque.

rockatansky

...needless to say that this person was me, if someone has any doubts. That was the first time I was using the digital snap-on (second hand and torque checked, but not the batteries. my fault). Since then I feel more comfortable with the click sound. But sometimes is useful to see the torque value growing at the display.