So while I'm doing my oil line/check valve adventure (almost done-other thread updates to follow..) and have one HE off already, I'm looking at the oil return tubes and thinking that may be part of the leaking issue. I'm able to turn them and it appears they will pop out without too much effort. There is a large spring that seems to be expanding the tube. It looks like I can just compress it and pull the end away from the case, then pull it out of the cylinder head.
Is it really that easy? I looked on the Pelican site and they talk about using vice grips to squash/compress the tube and then get an expandable one to replace it. Are 911 engines different?
I'm assuming there are rubber seals/o-rings on the ends of the tubes that should be replaced? I looked on 914Rubber and didn't see anything. I found some on Pelican, but almost $10 each, and there are 2 per tube. Any alternatives?

There are two versions of these tubes

The “original” ones are a single piece. They are installed when the cam housings are off and being re-assembled. The only way to replace them is to crimp them, bend them and remove them. They are destroyed in the process.

The second kind are the two piece “ expandable” kind. They are designed to replace the originals without pulling the engine apart. They are a bit of a compromise. Joints, o rings leaks etc. no other choice unless you want to do a top end rebuild/reseal.

There are many versions of after market expandable oil return tubes for the
six cylinder engines.
The best and most effective expandable is the Porsche version.

I am going to be doing this soon, my plan is to take my time and pull the tubes.

DO NOT CUT THEM!!!!! that will introduce material into the engine that you do not want, hopefully it would not make it into a bearing, but it will most likely go through the scavenger side of your oil pump.

@Rgalla9146 Rory do you have a part number for the Porsche one? I have a bunch of them collected from a friend, but want to make sure I get this correct. Do it once do it right.

Dow Corning 111 on its way to make the o-ring placement easier.

Other trick, is use a couple of hose clamps and then take a pair of E-Clip pliers they have a nice jaw to expand the tubes into final location.

Dow 111

Example of the pliers I referenced, I have this set and love them.. Makes CV repair a breeze, also needed if you work on things like tranfercases, and other axle situations.

On the 914-4 pushrod tubes I used a Loctite product I may use that here instead of the 111. Loctite, this product really helped me get to a leak free type -4. And a Teflon based pipe sealant, I am torn, experience says that those worked great, other people say 111 or even petroleum Jelly will do the trick.

One thing I do know make sure you get the proper Viton Seals, anything else will be gone in no time.

Thanks. So can anyone identify these? At least 30yrs old, probably closer to 40+ if they aren't stock. Pretty sure one or more are leaking at the case end, but it only seems to happen after the car sits for a long time and the oil drains back into the sump (hence the reason I'm doing the check valve). I'm not really up for pulling them and finding out I can't get new seals so they have to be replaced. Click to view attachment

I was always told the LASO with dow 111 silicone grease to install but Rory is the expert here.

@Rgalla9146

Never saw that type. The o rings look black. Never saw springs. The newer o rings tend to be green.

There has to be a seal some where inside to seal the two tubes against each other, also probably an o ring.

Might be worth trying new o rings and seals, but this is a PITA job you only want to do once.

I've seen two versions of the expandable tubes. One is made in steel other in aluminum. I'm not sure which is better but I do know that they are a real pain to install. As for removing the old tubes I only did one before. What I did was crush the old steel tube and bent it enough to slip out of the cam tower. Have fun installing the new one. Another pair of hands helps. One person holds one side that's seated while the other tries to seat the other end while trying not to crush the new tube. Use the green o-rings with some type of lube. I've used the DOW corning 55 and seamed to work fine.

As for the tubes on your engine, I've never seen them with the external springs like that. Best of luck.

I was told to stay away from the fancy machined aluminum ones.

your tubes with springs are aftermarket
I've never seen that style before... but some aftermarket design that didn't last through the years.

the current aftermarket design works well
so you may want to consider switching over to that

or reuse what you have with the right o'rings

but definitely yours are not stock from the factory style.
brant

I quit using the liquid Teflon pipe dope on the T4, I use Dow 55 for O-rings . Dow 111 is likely similar, basically an O-ring grease.

I've never seen or heard of ones with springs.

The 2-piece ones are fairly easy to install, you just need to get a couple appropriate size
hose clamps, place them a screwdriver-blade distance apart and use the screwdriver to expand them (may require re-positioning a couple times to move them the full distance.)

yes the expandable tubes are a bit hard to expand, but saves having to remove the half of the top of the engine to replace the original ones.

OEM expandables.
the cleaner ones are on an aluminum 2.0 in my white car
The others are on a 3.0
part # 930 107 040 01
usually comes with green O rings

Well, I may have done them in the late 70's when I had the top end apart, or George/AA did them in the late 80's when I had him do some work on the car. Either way, they certainly have lasted and no apparent corrosion. At this point I don't think I'll "fuch" with them. No leakage from the outer side, and it appears the case/inside only leaks when the tank was draining back into the sump and filling it up.
To my mind, a spring loaded assembly like this would be better than a rigid tube. I'll pull them if it starts to leak badly or when/if I do an engine rebuild. I want to get it back running before the snow flies.

I too have never seen that type used before,on a VW T1 yes but not on a 911 motor,if you can turn them thats most likely your leaks.
I used the alloy external spring type on a T1 1600 and they worked well,they were used when I got them so I replaced the internal "o' rings which turned out to be an odd size,ended up getting them from a hydraulic repair company.

I just tried turning them to be sure they weren't stuck. Maybe an O ring on each end, possibly cracked at this point. Still thinking I don't want to mess with them right now so I can get back on the road for a little bit.

If the leaks are small that's most likely the best thing to do,don't think you have a cracked "o" ring as you really know about that,most likely they have dryed out and shrunk a little in diameter.
Don't worry about oil leaks,I fix a couple then others start but you get there,I have one I can't fix but not losing sleep over it,cheers.

, how can this not be better than no spring at all, at least for after market? I've seen 'em before too.. but maybe it was type I, not sure. Do we know for sure that Type I's have different dimensions? I might be interested in getting some.

.

I found these, but I suppose they're Type IV (doesn't actually say, but..), not for a six.. I like 'em and will consider for my project.
https://vwparts.aircooled.net/Spring-Loaded...sh-rod-tube.htm

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The spring is on the inside of the replacement 911 return tube to compress it into the gap,no other reason,the external spring VW one is designed to compress the cup type (conical ?) seals in the case and heads.. different use but principal is the same to get around engine pulling your engine apart.

I worked on a lot of VW type 1/2/3 engines 'back in the day'. The pushrod/oil tubes are vastly different from a Porsche 6. Much smaller and as mentioned, a conical seal on the ends. I put the heat exchanger back on without messing with the 'mystery' tubes. Someday when I (or someone else) pulls the engine, we can get an answer. I did put a magnet to them, the spring is obviously steel, and it sticks about 1/3 of the length of the large tube. Maybe from the smaller steel(?) tube being inside. The rest of the large tube appears to be aluminum, but pretty heavy duty. Again, I would have to pull one, but sure looks like a nice solution for the original fixed tubes, or compression replacements. These are 40+yrs old, so have held up well.