Re-use expandable oil return tubes?
 

Can I re-use these collapsible oil return tubes with new O-rings ?

Yes. If they are the steel collapsible tubes, make sure you use the green o-rings.

And new circlips too.

That is great, but who's got these rings? I have circlips but no rings.

Pelican should have them, even if they are not listed.

Here's the part numbers from Pelican:

OEM Outer Oil Return Tube Seal (sold per each, 2 req. per return tube), 911/911 Turbo (1974-89)
K-701-465-40 $1.75

Inner Seal for OEM Expandable Oil Return Tubes Only (sold per each, 2 req. per return tube)
K-701-470-40 $1.50

Circlip for OEM Expandable Oil Return Tubes Only (sold per each)
N-012-425-1 $0.75

I don't see the need to replace the circlip unless it's bent out of shape and distorted.... and even then. This is not a high stress area like the end of a piston pin. The circlip merely provides a stop that keeps the tubes from telescoping to a shorter length once installed.

MHO,
Sherwood
http://members.rennlist.org/911pcars

i use stock one piece tubes if the heads are off. why risk a leak at the joint. one less thing to potentially leak down the road. they're cheap.

@ 8$ a piece why chance the leaks? I tossed mine.

"@ 8$ a piece why chance the leaks? I tossed mine."

What, O-rings or drain tubes? If the former, pretty expensive O-rings. If the latter, what's to wear out?

Sherwood

Sherwood, the only reason I suggest replacing the cerclips, is why cahnce it at $3. I understand they are not in a high stress situation, but if I were to pull my return tubes and replace the ( the expanding ones) o-rings, I would replace the cerclips as well. Because I know how much un-finess I had with mine.

I agree with JW, if the heads are off, put one piece style back on.

No fight on my behalf please.

1. The heads are NOT off. I pulled the engine to clean up the 1/4 thick of sludge on the engine, the case, the engine compartment and to do some seals replacement. I happened to grab the collapsible return tubes and turn them, and therby break the seals. So, I might as well replace all the o-rings while I have it out.

2. My collapsible tubes have this very thin steel circlips that have been on there so long they break off like carbon.

I have a box full of different (new) out-side circlips so I will use them in place of the old broken ones.

THanks for the part numbers of the seals, I will order them tomorow.

If you have your heads off, buy the one piece tubes. Collapsable tubes were meant for engine-in-the-car replacement.

Make sure you put the small end of the collapsable tube in the head. New O-rings with Dow corning 111 silicone on them.

AFJuvat

Ahh ok. I was in the situation You were in before. I went ahead and replaced them since I didn't know how old or what condition they were in. I also reused my clips

Definately heed AF's advice and use the Dow Corning 111 silicon, or you'll never be able to slide the tubes against each other. Also, make sure you put the larger tube on the correct side, so the direction of flow is from large tube to small tube. If you don't, you could get a leak. I think the flow is from the heads back to the case. Is this right, everyone?

Charlie

Yes, heads to case is the path of oil flow.

Wait

My collapsibles tubes were previously installed with the big tube into the block and the skinny tube into the heads. According to this discussion, that is backward, right?

No. Charlie half-misspoke. The big end should be toward the case.

It should not make any difference which direction they are installed as long as they fit.
When the engine is running the oil flows from the heads to the case so normally you would want the oil to flow down hill, I.E. from smaller diameter to large. But there is no real pressure and the flow is not great enough to create a velocity enough to leak past the o ring if it is in good condition and has the proper static crush.

If someone really wanted to get anal with these tubes they would replace the viton o-rings with Kalrez (tm) o-rings which can withstand a higher temperature and has better chemical resistance. unfortunately they also carry a higher price tag, probably around $1000 or more to seal all 4 tubes. The advantages of Kalrez does not justify the extra expense IMO.

OK,

Finally found a set of O-rings. These tubes are not the Welmeister or the Pelican ones, and I am guessing they are factory collapsible tubes. The o-rings were hard to find. I finally went to a Rubber place, they pulled out the correct teflon-silicon-viton ones (they had it all). When it is time to pay, the secretary said "not worth it to write up, just take them." Wow, Chirstmas comes early this year.

I had to use some moly-lube and these tubes slide right in.

Thanks every one.