Replaced my oil return tubes without removing exhaust

[Christien]

Yes, it can be done! I was very tempted to remove the exhaust after I did the first one, but I hate taking it all off and replacing it. I've done it 3 times over the last few years, and I swear it's the most miserable job I've ever done on the car. So here's what I did - maybe it'll help some poor soul in the future.

I've got a 1982 3.0L engine with 1972 exhaust, and the oil return tubes were, I believe, original to the engine. They weren't the crushable aluminum ones, but thicker steel. The vice grips did nothing to deform them - maybe a tiny dent. I tried the dremel, hacksaw, angle grinder (wouldn't fit), anything I could think of. I ended up drilling a couple holes in them, first with a small bit, then a large one, straight through, then wobbling the drill back and forth to enlarge the hole. The 2 nearest the rear of the car I could reach with the hacksaw, so I was able to saw a bit on those, too. But the drill trick is what worked the best. I got a lot of material drilled out, then with a combination of different size crowbars and vice grips, I was able to wrestle the mangled bits of tube out. There's a risk here of getting metal shards into the engine case, so I was careful to watch where stuff was flying, and cleaned out the holes before installing the new ones.

I started installing the new tubes with the passenger side rear one. That was a mistake - start with the front pair, because the space there is tighter, and it's easier to work without the rear tube in place. But it's still possible. I lubed the tubes and seals up with the recommended Dow Corning 111 grease. I also used the hose clamps, though what I discovered was to put 2 clamps on, one on each piece of the tube. I'd get it in place and spread it as far apart as possible, then clamp a set of vice grips on each end. I'd use the heat exchanger as a fulcrum and lever both vice grips to extend the tube (so basically you're pulling the handles of the 2 vice grips towards each other - make sense?). As it got close, I would then use the same technique on just one end to snap the end of the tube into place. This provides some resistance when you start extending the other end of the tube (though not enough). I'd leave the vice grips in place, then use the crowbar on the hose clamp to extend the tube and push the other end of the tube in place. The combination of resistance from the first end being snapped in, plus the vice grips on that same end wedged against the heat exchanger provided enough resistance for me to crowbar on the hose clamp to snap the other end in place. Once the tube was fully extended, it was just a matter of using the crowbar to slide the c-clip into its groove. I'd slide a bit of it, rotate the tube, slide some more, etc. until the clip was in place.

I did have to loosen and move the hose clamp a few times, depending on where I could set the back end of the crowbar to lever with it. Sometimes it was easier to crowbar on the engine case side, sometimes easier on the other side (hence using 2 hose clamps).

I'll tell you, though, it's a b!tch of a job with the heat exchangers in place. If you ever have the exhaust off for any other reason, definitely replace the tubes while you're in there - it would be a 1-hour job with no exhaust there. In this case, it was probably almost 10 hours. About an hour per tube to remove, and an hour and a half to install the new one. In the end, though, I'm still glad I did it without removing the exhaust.

[mdripley]

Thanks for sharing your experience with the return tubes, I may be doing that very job in the near future.

[ozracer]

thanks for the input I need to do my other two as well. Lucky they are on the side thats easy to get too.

[BrianS]

I was replacing the Oil Return Tubes on my 1987 911 and had to end up created a tool to help. I will take a picture if anyone is interested. I used two small "L" brackets, a long bolt, going through both brackets and a "welded-on" nut on one of the brackets. With this, and a couple small expandable "radiator" clamps and I was able to push the tubes apart and directly into place.

Once completed, I would simply unscrew the clamp and move to the next tube. I have no idea how anyone would have accomplished this without removing the heat exchangers / exhaust on my car without something like this.

[PDACPA]

I used two pry bars. Was a pain, but no need to remove the heat exchanger. You have to do both tubes on the driver side as the one closer to the front of the car cannot be installed without removing the tube closer to the back of the car.

[john walker's workshop]

big channel-locks to crush the tube. two extra long large needle-nose pliers to get the o-rings to slide in. left front one removal by flat end prybar. pry it into a V shape. left front snap-ring install by walking it down the tube by alternate side pushing from above the exchanger with a screwdriver. you'll get it down to 1/2 hour for all of them.

[shrtshck]

I managed to change the oil return lines on my 87 by following (for the most part) the instructions posted on the Tech Center. Used a gear clamp on each end to pry against to get the ends into place and long slim "C" clip pliers to lock the clips in to place. I recall that it took a lot of finessing to get all installed but it can be done.
One thing I can add is to clean the case as much as possible before removing the old return tubes, the bottom side of my engine was encrusted with oil and accumulated grime. Working on your back under the engine trying to work the new tubes into place is no time to be worrying about getting dirt on the nice new seals.