Can a flexible oil line be repaired?

[tirwin]

On my '83 I have an oil leak in the oil line in the right rear wheel well that goes between the hard oil line at the back of the engine and the thermostat.

The leak looks like it is coming out from one of the crimps in the flexible part of the line. After getting the engine back in the car it seems like it is quite a bit worse. Maybe moving it around did it... who knows.

I'm just dreading messing with that line because I'll have to deal with possibly stripping the aluminum thermostat threads. Is there a way that I can try to re-crimp the flexible line fitting in place?

[bpu699]

I have never tried this, but I suppose you could dremel off the crimped material, and just use hose clamps...

In theory, should work.

[Ayles]

A new line off the thermostat is either $75 or $120... Is trying to repair it throwing good money and time away?

You don't have a thing to worry about with your thermostat if you decide to replace the lines. Just carefully cut the old ones off. That way you don't risk the threads on the thermostat by wrenching on them too much.

For me at least, had I known the cost of new lines before I started I would not have wasted the hours trying to remove them.

[Porsche 2]

Just fixed both on my Carerra. Remove the rear nuts on both lines first, anticipating about a cup of oil dump. then remove the front two nuts. Take these lines to reputable hydraulic hose mender, --- my bill was $140 total. Make it clear that the replacement new hose with the pipes must be exactly same length as original lengths. Fit the repaired pipes back, fastening the front nuts first, easy job.

[jlex]

^^ That's probably the best way to do it. Am wondering, though, if cleaning the crimp off real well with brake cleaner, then covering the thing in hi-temp black silicone would seal it... Too much pressure, maybe?

[jwakil]

Originally Posted by jlex

^^ That's probably the best way to do it. Am wondering, though, if cleaning the crimp off real well with brake cleaner, then covering the thing in hi-temp black silicone would seal it... Too much pressure, maybe?

I would wager the silicon solution would be a waste of time. If there is enough pressure to go through a crimped joint, it will definitely leak through a silicon to metal or hose joint. First thing I would try is using a metal screw clamp over the crimp, and see if you can tighten it down enough to deform the crimp and get more pressure on the hose. This might be enough to seal the hose to the barb inside.

[john walker's workshop]

I've had good luck removing that fitting from the thermostat by using a chisel bit in an air hammer. Seems brutal, but place the chisel under one of the points of the nut and give a couple of short hits to slightly rotate the nut. After that, it comes right off. Haven't messed up thermostat threads in years. I have a snapon rounded crowfoot that gets in there to tighten it back up. Just buy a new hose.

[tirwin]

Thanks for the good advice everyone! I think I'll attempt to R&R the oil line.

I've got a follow-up question. I have seen the 30mm replacement nut that Elephant Racing sells. Is that useful in this situation? What's the difference between using the ER nut and putting anti-seize on the new oil line threads?

John Walker - I was in your neck of the woods this week on business. I was sitting in Joey's in Bellevue last night and I saw a beautiful yellow 914 stopped at the traffic light in front around 6pm.

[BoxsterGT]

Ayles has the right advice, replace them w/ new from our host. They are not expensive and you have peace of mind when done. At $50 per special Elephant nut, you are better off with new hoses.

Unless you have lots of time to waste, try John Walker's method first. If that doesn't work use a dremel to weaken the nuts by slicing PART way through, then hit them with the chisel.

Make sure to use anti-seize paste when installing the new replacements.

Len

[tirwin]

Thanks, Len. I did order the new lines... they are waiting to be installed. Been a little too busy to install and besides after not driving the car for 9 months, I have been having too much fun.

[boyt911sc]

Originally Posted by tirwin

Thanks, Len. I did order the new lines... they are waiting to be installed. Been a little too busy to install and besides after not driving the car for 9 months, I have been having too much fun.

Tim,

I am cheap and frugal. So I try to build and fix my oil lines. But times come when you need to bite the bullet. These oil lines are not that expensive and if you figure out the time and effort to replace, repair, drive all over town to the hydraulic shop you end up spending more if you value your time. Time is gold!!!! If you are reluctant to touch the thermostat now, do you think it would be much easier next time?

You made a good decision in buying the oil line. If you will have difficulties getting off the leaking oil line in situ, cut the nut or drop the whole unit (from end to end).

Tony

[tirwin]

On a related note to the oil lines, I've been wondering about something. I seem to really have a hard time getting the engine up to the 180° mark on the thermostat as compared to what I read from others on here. I really have to push the car hard on hot days for a long time to get the temp up. I replaced the internal oil cooler while the engine was out and that didn't make any difference it seems. I'm just starting to wonder if it's possible that the external thermostat is stuck open? I know that oil is getting up to the front cooler.

[Joe Bob]

Trucker hydraulic shops, cheap and reliable.

[BoxsterGT]

Most local hydraulic shops do not have the correct Metric Crimp Sleeves and Jaws. They crimp over the bump on the end of the fitting thats meant to retain the hose, crushing it and causing a premature failure.







This is what is correct:



Shown is a re-hose of a early 911 oil line that was NLA from Porsche.

Len

[boyt911sc]

Originally Posted by tirwin

On a related note to the oil lines, I've been wondering about something. I seem to really have a hard time getting the engine up to the 180° mark on the thermostat as compared to what I read from others on here. I really have to push the car hard on hot days for a long time to get the temp up. I replaced the internal oil cooler while the engine was out and that didn't make any difference it seems. I'm just starting to wonder if it's possible that the external thermostat is stuck open? I know that oil is getting up to the front cooler.

Tim,

Unless you physically test and inspect the engine and auxiliary thermostats, you won't know if they are working correctly specially when you have some lingering question at the back of your head. For peace of mind, check them. A visual inspection during heating in a water bath was what I do for this type of investigation. I will try to find the picture showing four (4) thermostats with different valve openings at same temperature.

Tony

[tirwin]

Thanks, Tony. I was just thinking that while I have the oil lines off is the perfect time to go ahead and check the external thermostat. It would be helpful to know at what temp the external thermostat is supposed to open to the front oil cooler.

For a quick basic check, shouldn't the following work? If I monitor the temp of the oil lines from a cold start, I should expect to see a temperature differential on each side of the external thermostat until it opens. If there is no temp difference then that probably means it's stuck open and I need to bench test it further, right?

I'm hoping that I just have a really efficient oil cooling system, but it would be good to know one way or the other for peace of mind.

[DRACO A5OG]

Oh wonderful

Just discovered weeping from one of my flex lines, at least now I have yet another leak to fix ��

[DRACO A5OG]

Just found this posted Pic:



One side looks like it is holding that was not cut. I am going to give this a try, I have a bunch of those Oetker clamps.

[Jcslocum]

Cut the old ferrule off with a dremel and crimp on some Oetikers. You can get them just up against the ridge on the inner nipple. A second one for good luck.

[DRACO A5OG]

Hey Brother Jon,

Do you recall the size you used?

Tia,

Jim