Project Difficulty Level Question - SC oil lines
 

I need to remove and flush my oil lines and tank after rod bearing material went through the system (just to be safe). I've had the oil cooler (Carrera cooler) flushed and tested at Pacific Oil Cooler Svc so that should be good to go.

How difficult is this project? It seems pretty straightforward. Looking for comments and suggestions. Thanks.

Removing the oil lines from the engine and the oil tank are not too bad. But depending on their age and condition, they may not release from t-stat. You often have to strike them to break the crud free and possibly cut the nuts to split them. Then you can replace the nuts with one of Elephant's replacement nuts and washer.

On the other hand, the oil lines on the underneath of the t-stat can be a bear. You'll want to mount your t-stat in a bench vise and those will take some time and patience with striking, heat, penetrating lube to get them free.

A good way to swab the brass oil lines is to tie a piece of rag (make extra sure it's tied tight and won't come loose 1/2 way through the tubing!) to some strong braided string. On the other end of the string tie a few M10 or similar size hex nuts. Fish the string through the tubing with the weighted nuts and then dump some solvent in the tubing. Pull the string through and let the rag swab out the tubing. Repeat & replace the piece of rag as necessary until the rag comes out clean.

You'll also want to remove the caps on the thermostat and clean that out. You have to remove both caps and not just the large cap with the temperature regulator in it. Crud material definitely gets collected in the smaller pressure relief section of the t-stat body and you must clean it out.

I use a pipe wrench to remove the slotted caps and discard them. Replace them with hex head caps. JimmyT here on the forums makes very nice hex caps for a very reasonable price

http://forums.pelicanparts.com/porsche-911-technical-forum/790036-auxiliary-oil-thermostat-hex-caps.html

I did exactly what Kevin suggested and it was fairly straightforward.

Disconnected the rubber lines from the tank and the hard lines from the cooler up front, dropped the whole shebang with the T-stat and walked it over to a vise. Several days of penetrating oil, torch heat cycles, and all 4 connections came off the T-stat with no damage.

Same process for the T-stat caps with penetrating oil, torch heat, pipe wrench over the caps, clean the inside, and Jimmy's caps to seal it up.

Not difficult at all, just need to be patient and not bugger anything up too badly.

Also, when re-torquing the connections at the T-stat in the installed position, tighten the inner ones first with the outer ones out of the way, then maneuver the outer ones in place and tighten those last. Didnt seem obvious until I struggled with it for some time first. You can also mark the lines and T-stat orientation with a sharpie before removal, tighten on the bench and install as a unit.

This is interesting, because I just went though this myself. But as I did so the following question came to me regarding the front oil cooler and lines'

Since the oil passes through the cooler after exiting the engine via the scavenge pump, and since it goes through the oil filter after passing through the front cooler circuit and before it goes back into the tank, why is flushing the front cooler and line critical? Wouldn't any debris there be caught by the filter before going back into the system?

When the engine munches a bearing(s), that debris falls into the sump. Even though the pump has a screen on the suction side, smaller debris crud can get sucked up and pass through the screen. The pump grinds it through the rotors, tears up the inside of the pump and then sends it off to the thermostat and oil cooler and then back to the tank where the oil filter catches a lot of it. If the filter gets full of crap it can go into bypass mode and send contaminated oil back into the tank to feed the engine and continue the process of distributing crud through the engine

Don’t assume the filter protected things. You need to clean any location that oil gets into to avoid an “encore presentation” of bearing crud causing future damage after your cleaning efforts

Ok, I can see that.

One thing I intended to mention was a way I found to break the thermostat loose from the lines running to the front cooler. I had no problem (after the usual Kroil soaking for a few days and applying heat) getting the lines off aft of the thermostat, but the others were a different story.

To me the one big issue was the inability to counter hold the nuts while trying to turn them. The one day it hit me; stick something in one of the thermostat bores to use as a lever. Obviously whatever that was couldn’t damage the aluminum housing; no breaker bars, bolts, etc. so I measured the bore and went to the hardware store.

Solution? Small hickory hammer handle! I stuck the small end in the T-stat and as torque was applied to the wrench the hammer handle contacts the inner body providing the counter force.

Another issue is the wrench; the normal open end oil line wrenches require you spend part of your attention keeping the wrench lined up on the nut. Solution? Get a 36mm crows foot. The one I acquired, a Martin, has a deep enough ring that it was really self-aligning. That wrench, the hammer handle, and a pull pipe had both nuts loose, I damaged threads, in about five minutes!

$10 for the hammer handle, $40 for the wrench, a little heat, and lots of time and headache saved!

I've had good success holding the t-stat in the vise with a pair of plywood scraps. I cut them into small squares and they do a great job of grabbing the t-stat w/out damaging it. The squares are also really durable and have lasted a number of years.

For anybody "local" in the US, if you need a thread die to clean up the t-stat external threads just let me know. I can send it in a USPS flat rate box for $8 or whatever the going rate is nowadays.

I bought the M30 x 1.5 die to clean up the threads on oil line connections and it does a nice job of cleaning up boogered threads, within reason. If the threads are totally hosed, the die isn't going to magically recreate them. But if they're just a bit roughed up from corrosion in the nuts, it'll dress up the threads to allow the nuts to mate properly.

One other tip that comes to mind. Someone might think "ah screw it i'll just cut the oil line since i'm going to replace it anyway. Then I can fit a socket on the nut and zip it off with my impact gun." I would strongly recommend against that. A buddy and me did that on his '87 911 many years ago. Oh, it got the nut off. But unfortunately along with the nut came a big hunk of the t-stat casting. :eek:

This kind of question always makes me think of the concept I call "the Application of Force". Nothing very original...but having been a dealership service manager for some years and thus around some truly primo techs (and some hacks), I learned to admire not just their understanding of machines and systems, but also their ability to apply just the right amount of force when disassembling or putting something back together. Some amateurs and DIY's grasp this immediately and can walk that (ideal) line between getting the job done reasonably quickly without damaging (or destroying) anything. Others either break stuff or take massive amounts of time. We'd look for this with new kids: do they have "the hands?", we'd ask. Having The Hands was closely linked to mastering the Application of Force!
So I'd urge the OP to make sure he has the right tools and thinks through each application of force involved in this job. If the wrench slips, where will it end-up? Make sure not in your teeth. Similarly, think ahead about your knuckes and fingers. Consider getting some Mechanix gloves or best quality latex gloves. I used my MAPP/Oxygen Bernzomatic torch to heat the lines I had to pull from the T-stat for my SSI installation...made sure I had a fire extinguisher immediately at my right hand. I'd bought the SIR wrench set. All these things sound obvious, I'm sure. Thanks for reading my thoughts and best of luck to you. John in CT.

great suggestions all thank you! now I just need to find the time in between chasing 3 kids and a working wife around! Jon

Yup. Application of Force. Some folks are better at it than others.

Removing a tie rod end from a steering knuckle. The mechanics don't use pullers. They WHACK the steering knuckle and the conical bolt lets go. Sometimes, this requires holding something heavy (sledge or whatever) onto the other side of the steering knuckle. So that the steering knuckle will deform and evict the tie rod bolt.


Other times, a dead blow hammer is the right force. Or a mallet. Or a plastic-face hammer. I understand what jjeffries is saying. Mechanics are artists. The good ones, anyway.