Oil Lines on thermostat....

scca_ita · 03-11-2002, 03:12 PM

I want to clean out the used lines I bought but I have heard it is risky to remove the lines to/from the cooler because the thermostat housing is aluminum and the treads will strip off.

Is this true?

Superman · 03-11-2002, 04:02 PM

Yes, it is true that some folks have quite a bit of trouble with those (thermostat) connections. Some of those connections are so corroded that there is essentially no hope of separating them. Others say you can cut the lines off, or at least the big nuts, but of course that destroys the oil line. All I can say is to be careful if you're gonna cut your nuts off.

I am going to try to remove one of my lines from the thermostat, but I will not risk breaking the thermostat and I would destroy the line only if the new line will fit, which I don't know yet.

Early_S_Man · 03-11-2002, 05:26 PM

With a used system that isn't installed on the car, yet ... you might want to try cleaning off all oil and grime from the thermostat with brake degreaser/cleaner spray and try brushing or soaking in some plain household vinegar. it is not very aggressive, but it does help remove and loosen corrosion. The soaking need not be more that a couple of hours, but if applying by brush only, you probably need to apply every 15 minutes or so.

Again, with the thermostat and lines off the car ... before trying to apply any torque to loosen the European flare nuts, put one side on a large vise with a flat anvil working surface, and hit the opposite flat aquarely with a large mallet or hammer, several times in order to break loose the encrusted corrosion. It would probably help to have an assistant, and a piece of bar stock would help to minimize damage to the flats of the nut. Rinse off the thermostat and flare nut (blow off with compressed air to dry) before trying to loosen, and apply penetrating oil overnight ... just to improve your chance3s of NOT stripping the aluminum threads.

scca_ita · 03-11-2002, 05:35 PM

What if I pull the actual thermostat out of the housing. would that give me access the the forward lines for cleaning?

Sunroof · 03-11-2002, 05:40 PM

If you have one of those thermostats that look like an artificial heart I was advised by my mechanic that he uses heat to get the lines apart. I certainly would never mess with that. I have heard of others on past threads that have taken the lines from the front cooler to the oil tank off just to access the thermostat.

I would like to know just where you can obtain that thermostat as I understand its megabucks!!

Regards
Bob
73.5T

Early_S_Man · 03-11-2002, 05:41 PM

Yes, it would ... I suppose you could plug the forward ends, or clamp the rubber lines (if it isn't a 'trombone' system) with large C-clamps, and try pouring in some B-12 Chemtool, and let it sit overnight!

jwetering · jwetering's Garage

I just went through the "character building" exercise of removing the oil lines from that thermostat. Let me tell you, the lines would not come off cleanly on my 1978. The lines are steel, the thermostat is aluminum. I used Wurth penetrating oil and a MAPP gas torch. Finally I resorted to splitting the nut off of one of the ports...

There are four ports in all. The worst case was that the seat of one of the ports went with the steel nut. That was on the port where I split the nut. Another one of the nuts took ALL of the threads off of the thermostat side. Two lines came off cleanly....there is hope. Do note that the location of this thermostat does not alllow a lot of leverage, or room to move a wrench. The nuts are 36 mm. You need a 12" crescent wrench at the minimum.

Also..I got a new thermostat for less than $250. I won't name the source out of respect for Wayne, but they're not difficult to come by.

ChunkSnoW · 03-12-2002, 01:49 AM

the problem i had with the lines wasnt so much the threads but
the seat on the thermostat where the union screws in and the copper/aluminium washers sit was so coroded i couldnt get a seal and had to replace the thermostat
another thing i u replace the oil pipe from the filter to the thermostat with a new one from porsche they changed the design
slightly and the pipe tends to kink behind the suspension porsches answer to this is to put a clamp on the pipe to keep it round!

-chunky

Thomas Owen · 03-12-2002, 04:17 AM

I replaced the rear lines recently and after having soaked the fittings in Blaster they came loose immediately. I understand Performance sells a piece to repair the threads if they become damaged, not necessary to replace the entire thermostat.
Good luck,

Formerly Steve Wilkinson · 03-12-2002, 04:48 AM

If you do strip the threads on the thermostat, there are aluminum fittings that screw onto the stripped threads and provide you with fresh threads to reattach the oil lines to. I assume Wayne carries them.

Stephan

KTL · 03-12-2002, 05:36 AM

I did the oil line removal from the thermostat this past weekend. Same deal as the others. Nuts were pretty stubborn, but with some heat and back and forth massaging of the nuts they eventually let go and came off cleanly enough to be able to save the thermostat.

I did have to cut the oil tank line with a hack saw as the line did not want to free itself from the nut. Kinda sucks but that's the way it goes. I think i'll make a new braided line instead of buying the factory style replacement line.

Here's the repair adapter Stephan mentioned:

Pelican carries it.

http://www.pelicanparts.com/catalog/shopcart/911M/por_911M_oilsys_main.htm

antsg · 03-12-2002, 05:39 AM

On my 77' I sprayed WD40 on all the threads twice daily for 2 weeks before removing the pipes from the thermostat, and off they came without much drama. Before doing this i couldn't even budge them. This should work most times as you then give the penetrating fluid time to do it's job. it's no good spraying it on and then trying half an hour later.

Clark Griswald · Clark Griswald's Garage

Actually heat will work against you on the tstat side connections. The tstat is aluminum, the hex nuts that retain the oil lines are steel. Aluminum has a higher coefficient of expansion than does steel. So if you heat them up you are making them tighter!

Sometimes a heat cycle can create some movement between the hex nut and the tstat due to the diffferent expansion rates and that will help, but you should then let them cool before attempting to turn the hex.