Oil Return Tube Reinstall

[jmills]

And now the reinstall.

I could not find Dow 111, but I bought this stuff.


Like the Dow, this is a silicone valve/O-ring lubricant/sealant. Once I lubed the O-ring and the inside of the larger diameter tube, I could slide the tubes very easily.

I used the hose clamp method and two small pry bars to push the tubes apart.


I found that if you can expand the tubes enough prior to installation (or by hand) so that the ends of the tubes will sit in the holes, it makes it easier to expand the tubes into the holes. If you try to expand the tubes with one end seated, the other end moves around and it is hard to get it lined up.

On the driver's side, you will need to install the forward one first. The heat exchanger is in the way, so expanding them with two pry bars back to back won't work. I put a hose clamp on each end of the tube and used the heat exchanger to pry against. Here is a picture of the outside.


There is a hose clamp on the inside in about the same location.

And here is the final product.



Thanks again for all the help. I am sure I will be back with more questions and I work my way though the oil leaks.

[PushingMyLuck]

Originally Posted by kohho

Wow -what a difference. I looked all over town and finally found the DOW 111. Auklands-Grainger here in Vancouver BC carry it. The assembled oil-return tube was very difficult to slide apart when I was using silicon grease, then motor oil but once I cleaned them up and used the DOW 111, the two tube pieces slide easily. I'll try the install again tomorrow.

Dow Corning Silicone Valve Lubricant & Sealant 111 MIN 12 - Amazon.com

[PushingMyLuck]

Is crushing the oil tubes an accepted method of removal?
It seems very risky to destroy something on the way out.
If you can't remove it, you're screwed now.

[PushingMyLuck]

Why are the OEM tubes 1-piece and the replacement photo 2-piece?
Also are the tubes reusable?
Why not just replace the o-rings at the ends?

[Hugh R]

They put the original tubes in as they build the engine. You can't get the old ones out without crushing them and you can get new one piece in without taking the bottom end apart.

[jmills]

You can replace the o rings on the two piece tubes since you can get them out without crushing them. They will come out the same way you put them in.....in theory at least.

[boyt911sc]

Originally Posted by Hugh R

They put the original tubes in as they build the engine. You can't get the old ones out without crushing them and you can get new one piece in without taking the bottom end apart.

Hugh,

How did they get the one-piece OEM return tube/s installed with the engine completely intact? Thanks.

Tony

[theiceman]

I think maybe he means that you can put the one piece units in while you are doing only a top end.

[bryanrex]

Nice work on the oil return tube replacement and documentation! I just replaced the return tubes on my 1979 Euro SC today and it wasn't fun (having never done it before). On my car there are emissions air inlet tubes going into the head, and those tubes plus the heat exchangers (not SSI) render it a nearly impossible task, but it can be done!

On the driver's side you must pry the heat exchanger down with a pry-bar while using a rubber mallet to coax the oil return tube through the small gap. Do not bend the tubes, and do this without the outside oil return tube seals placed or you will probably damage the new seals. Place the outer seals after getting the return tube assembly through the gap (this is also difficult). You don't have to remove the air inlet manifold on the driver's side to get the tubes in, however on the passenger side you will have to remove the air inlet manifold or there is no way to get the tubes in place.

Removing the passenger side air inlet manifold is straight-forward, however due to oxidation I had a hell of a time getting it detached without stripping the fittings. Use a lot of WD-40 or thread penetrator. You must hold the nubs in place otherwise you could strip the aluminum fitting. This was a delicate process!

On the passenger side there is plenty of room to extend the tube once placed using the hose clamp method. I used only one hose clamp on the inner tube, and twisted a flathead screwdriver between the hose clamp and the lip of the outer tube in order to extend it. It extended about a quarter inch at a time and I kept relocating the hose clamp as the tube extended. Once you understand the process the passenger side could be accomplished in less than an hour.

On the driver's side however, extending the tube is next to impossible (due to almost no access). I placed a hose clamp at each end of the return tube, then used vice grips (wedged in place) to hold the side closest to the engine case in its seat. With that side of the tube securely in place, I then used a pry-bar against the heat exchanger to extend the tube using the outer hose clamp. It took about 2 hours, but both finally seated and sealed perfectly. Moving the c-clips into place is simple once the tube is extended properly.

Although I was successful replacing the oil return tubes on a Euro SC, I've heard from several credible sources that it can't be done properly without removing the heat exchangers and the air inlet manifold. It CAN be done, but it requires forcing a lot of pieces in ways they weren't meant to. Do not attempt this on a Euro SC unless you are very patient and inventive. I'll try to upload some reference pics in a bit.

[bryanrex]

Here's a picture of the undercarriage. The circles indicate air tube inlets that must be unbolted. There are three of these on each side, but only the passenger side air tubes need to be disconnected in order to install the oil return tubes.

The arrows indicate where I attached hose clamps to help extend the tubes.