mike77

My steel fuel lines are rotting out. I see you need to drop the suspension to swap these lines over. I'm looking into nylon or rubber replacement.

Can anyone confirm the diameter of the hard lines?

Also I see that some people who have done this use nylon lines with compression fittings. I've just been speaking to someone at pirtek who advised against this saying rubber would be better. Any opinions on that?

murray928

I replaced mine with a combination of 3/8" smooth boreand 3/8 convoluted bore stainless steel braided ptfe." No need to drop suspension on my MY 1985 928 S2. Used the convoluted hose for the really bendy section in the wheel arch. Also replaced transmission lines with the same 3/8" smooth bore. Materials cost for all lines €454 = $500 approx. Really pleased with result.

mike77

So 3/8 would be 10mm then I think?

My problem is that I was speaking to a garage here in the UK who said they could sell me a nylon kit a few weeks ago. Communication seems to have broken down a little, i guess they are busy. Anyway I'm now booked in with my local indie shortly to do this and a few other jobs but I've no fuel lines for him. I think I just have to go with whatever advice pirtek give as i need to come up with a locally sourced solution pretty quickly.

mike77

Just to add, the two lines from porsche are not that expensive but the suspension drop labour hours worries my wallet a little. I also liked the thought of a rust proof solution as they like to salt the roads here

mike77

More questions. Does anyone know what pressure that these two lines run at?

Cheers
mike

John Speake

One is the return so low pressure. The injectors run at around 50psi so you want a good safety margin above that.

Igaffz

I've just ordered some 10mm nylon pipe + inserts for mine from eBay. I think it was £12 for a 5 meter length. I've also ordered some 10mm clips to mount them. My 85 s2 has nylon and compression fittings already but only over the rear wheel arch so I wanted to replace the lot.
I've had no problems as yet?


Ian

mike77

Thanks John. I'll tell the Pirtek people.

I was going to order nylon lines but the guy at pirtek didn't think that compression fittings were a good idea unless the section of the hard line they were connecting to were in good condition. He thought any surface rust or pitting could lead to a leak. He seemed to think rubber was safer.

I'll get back to them with the info about the pressure and see exactly what he's suggesting.

oaros

A thread link I saved, maybe helps.

https://rennlist.com/forums/928-foru...r-options.html

mike77

Ok that link suggest nylon is the way to go rather than rubber that the hose shop people are telling me. Unfortunately neither of the product links work anymore.

I spoke with a garage that does the nylon replacement but unfortunately doesn't sell a kit. The guy was pretty helpful though and told me what I would need.

7 meters 10mm nylon fuel line
2 compression fittings with olives
2 olive inserts
1 foot of fuel hose internal diameter
4 jubilee clips

So I took this list to the hydraulic hose shop and got hit with a few questions I couldn't answer and then they recommended rubber.

From the other post it looks like it should be 12x10 nylon line? And would that be the same for the fuel hose?

Also there were different fitting sizes for the compression fittings. So not sure there either.

As for the nylon lines are there fuel grade lines?

murray928

Check this out on ebay, rated for fuel and no need to drop suspension.
I have used similar with the convoluted type for the extreme bend in in the rear wheel arch.
http://www.ebay.co.uk/sch/i.html?_od...+10mm&_sacat=0

mike77

Hi that looks like a good option but I'm not sure I can get that on time for Tuesday, with the easter holiday coming up. I think I can get the nylon lines in time from the local pirtek. I'm not sure what size fittings I need though. From the looks of your link it would be AN8. I think the fittings are cheap so I could cover all the bases and get AN6 and AN10 too.

murray928

If you decide to go that route, you need to disconnect the old lines and take them to a specialist shop which supplies this ptfe braided hose so that the exact lengths required can be cut to size and end pieces fitted correctly. If the lengths are not correct they will not fit into the old steel pipe retaining clips on the underbody. Of course the car needs to be up on a lift to remove the old pipes. My mechanic ran the line directly from the fuel filter using smooth bore connected to convoluted bore for the extreme bend in the wheel arch, then smooth bore again up to the engine bay. He also had to make an adapter to connect the fuel feed to the intake in the engine bay. You would need a mechanic who knows what he is doing.

mike77

Sounds like I won't be able to get that sorted before Tuesday. He's an experienced mechanic but I'm not sure how much he'll be willing to play around with non standard parts although he has no problem fitting them if I bring them. I don't think the nylon kit will be expensive so I'll buy it and if he doesn't like the look of it then I won't fit it.

As I said above I didn't think the porsche lines were that expensive. I'm wondering if buying new lines cutting them at the suspension and then using nylon to bridge the gap would be an option