Torque on cam tower oil line?

[Decolliber]

Replaced aluminium washers at banjo bolt on left cam tower oil line, due to leak. How much torque for this bolt? Bentley does not say. I have a tendency to over tighten things, so I just did it lightly, and leak seems to be gone, so maybe I should just leave well enough alone.

[Formerly Steve Wilkinson]

I had a big leak show up in the other end of that line, where it goes into the oil-temp (?) sensor, at a recent DE and asked a friend who was there, who runs an independent Porsche shop, to do the tightening with his educated wrist, and he tightened it a lot more than I'd ever have dared. Dunno if it's the same kind of compression fitting that's at the banjo-fitting end of the line, but he said that line is one you need to really tighten and then recheck later on down the road.

Having said that, if you don't have a leak there, sound like you did it tight enough. Just recheck it every once in awhile.

Stephan

[KTL]

John,

You tighten those banjo fittings with the crush washers until you can feel the washers squishing a little bit. No additional amount of tightening is going to seal them better! Good to just snug them and check for any dribbles of oil. If dribbling, give them another 1/4 turn or so.

The connection at the center of the motor has a cap nut and a little crush/press fitting called a ferrule. These require more tightening than the banjo & crush washer arrangement, but you can still overtighten them as well. AMHIK (Ask Me How I Know).

[ebrownson]

John C

Do you have pictures of the leak, location, parts you replaced, etc? I just noticed some oil near one of my cam oil lines and want to see if we are looking at the same thing. Thanks.


Eric
83SC

[brittbolen]

KTL... I know this thread is OLD, but I want to ask you how you know that you can over tighten that oil like ferrule...

Anybody know if you can over tighten the fitting that goes into the engine block? (i'm got a leak on the right (passenger) side line... and I was going to try tightening everything before I start replacing things.

Where could I find those 2 crush washers (besides our host) would autozone, or advance auto parts have something like that. home depot?

thanks,

Britt, novice.

[KTL]

For those crush washers, you can substitute any kind of washer that is semi-soft. Copper, aluminum, plastic/nylon, etc. Best bet would be a auto parts store. Many cars use banjo fittings for the fuel system and you could easily substitute one of those washers even if it's a marginally close fit. Hardware store would be a gamble for these kind of washers.

I know it's easy to overtighten the inner fitting at the center of the motor because I did it myself. First fire-up after pulling the motor to fix a bunch of pesky leaks and new clutch. Fired up great and I was so pleased with myself. Then I looked underneath after I shut it off and there was a small pool of green oil (old Kendall GT1 that used to be green). Turned out to be the cam oil line leaking at the center of the motor. Yep. I overtightened it. What happens when you overtighten it, is that the cap nut pushes the ferrule (Porsche also calls it a cutting ring) down too far and it doesn't seal against the smooth tubing.

The fitting that goes into the case is probably not the culprit. It too has a sealing ring/crush washer on it, but i'd bet on the ferrule fitting. The case fitting would be more likely if you didn't counterhold the fitting when tightening the line and it then could come loose?

[88911coupe]

Is a sealant not an option for this situation? They seem to leak...a lot.

[KTL]

Which fitting is leaking?

There's many places:

-cap nut going into inboard side of engine case
-hose crimps
-brazed fitting banjo end
-crush washers for banjo.

The only situation i'd attempt sealant is #3 above. Otherwise, a leak should be solved with replacement of the line itself or the sealing part (crush washer or cutting ring). And once the cutting ring/ferrule cuts, it's not coming off.

[304065]

The answer is 35 NM (26 ft-lb). Be sure to use NEW factory crush washers. Don't just use anything or it will squeeze out and leak.

A 12 x 6 900 123 005 00

[RWebb]

sealant is a great way to send little oil gallery dabs of material thru the motor

No No No!

[KTL]

26 ft-lb for a fine thread banjo with crush washers? I'm surprised the spec is that high. Snug plus another 1/8th of a turn has always worked well for me.

[88911coupe]

Anyone know the specs on the other end? The end behind the distributor?

[proporsche]

hi Buck..35 nm....

[KTL]

35 Nm? That's way too tight and will crush the sealing ferrule, causing it to leak. It's a spherical fitting and therefore the tightness is merely keeping the collar nut from vibrating loose. It's the spherical surfaces coming together properly and evenly that ensures a leak free seal. If you over-tighten it, it can leak due to distortion

There's no spec for this collar nut end of the oil line. You make it snug and then tighten it a bit more like a 1/8 turn for good measure. You do NOT want to gorilla tighten this or it will leak.

[proporsche]

Kevin my bad..you are right ,silly me...20hm is just fine....anyhow here is the specs for the rest...never mind the greasy finger marks, it was in use for a while;-)
Ivan

[88911coupe]

Thanks, I must have over tightened it. However when I did the rebuild while back I was careful to not get it too tight then...at least that's what I thought. The other thing i noticed was the end of the hard line that goes into the hollow bolt/fitting, attached to the case, appear to be a little too long past the ferrule. By that I mean the end of the line is bottoming out in that bolt which leaves the ferrule too far up the line to snug down when I tighten the bolt. There is a very small "ridge" or ring on the line to keep the ferrule from moving down the line which seems to keep it from making a good seal.