Pushrod Tube Oil leak

[Pritchard]

I have a '74 2.0 with oil leaking from some of the pushrod tubes. I have replaced the seals twice with little improvement. Any ideas on how to stop the leaks?

[john rogers]

The current issue of Porsche Panorama has a short tech article just on this matter. Make sure of four things, the tube o-ring areas are not damaged, use the correct hi-temp o-rings, use the grease mentioned in the article and insure the springs are reinstalled correctly as they keep the tubes in place. Sorry I don't have the name of the grease as I don't have the issue here with me, but don't use permatex or other sealer that prevents the movement during expansion/contraction.

[rich]

For the benifit of us that don't get the panorama could some post the type of grease currently being recomended. Thanks

[mikeyz]

For those who don't get Panorama, you can get a free subscription when you join the Porsche Club of America (PCA). OR you can order copies of "Up fixen der Porsche" via a PCA member. Up fixen, has tech articles from Panorama magazine that are reprinted according to make model and/or year. Very helpful.

[john rogers]

Actually I use AmsOil 2000 racing synthetic gease and it works great at hi temps. I use it on the push rod o-rings on both our cars and the o-rings on the piping for the turbo charger on our '87 Turbo and it does not run although it does change color?

[Dave at Pelican Parts]

The grease mentioned in Panorama is a silicone lubricant, possibly a paste. It was NOT a silicone sealer like RTV. I forget the exact name, but I think it was a Dow product.

--DD

[Pritchard]

Thanks for all the help.

[Dave at Pelican Parts]

Heck yes, I'm interested! A dry 914? That would be a nice change for me... (Hopefully the fan seal I replaced will get me there.)

--DD

[rich]

I consider my self to be a real novice in the ways of the air cooled assm.,And I almost hate to admit it but; When I installed my push rod tubes I sprayed them with carb cleaner and slid them in. After the carb cleaner evaporated I back sealed the tubes. I ran the engine two summers with no leaks.(around the push rod tube anyway) I used red RVT. It's going to suck to tear down. Although I know better I couldn't resist. The devil made me do it!

[Tim Polzin]

Looks like everybody has some ideas on sealing push rod tubes. When I rebuilt my 2.0, I carefully cleaned the seating areas and applied a little white grease to each O-ring. When I inserted them through the head, I twisted the pushrod tube to allow them to seat. I had no problems with any oil leaks.

I have a friends engine apart now and one of the previous owners put what looks like aviation permatex on them. I think my first job will be to make sure I get all of that old material off before re-assembly. It really made a mess.

My 2 cents (just realized there is no cent symbol on the keyboard).

[john rogers]

We used to use a product similar to the Red RTV on boiler feed pumps and steam turbines and it would still be pliable after months of hi temp use. As long as it doesn't get hard or burn off it will work well. The actual amount the tubes have to allow for the expansion/contraction is pretty small so it would seal.