Oil Leaks....Where?...Oh, WHERE!

[n2582d]

I prefer Aviation Permatex No 2 as a TCM approved sealant.
I demonstrated a pushrod rubber that was split with an exacto, then re-glued together with Permatex (edit: LocTite Stik and Seal) Oil and Gas proof rubber-adhesive (AutoZone/Napa) and challenged a few guys to find any defect. ... I expect it to work fine and will report results later.

So you will be changing those numbers to read NX146YS and adding the required 2" "experimental" label in the side window?

[170C]

I checked my Permatex material and found avaition gasket material, but it doesn't say anything about being an adhesive. Stopped at Auto Zone this PM & saw Permatex RTV Silocone gasket material in several colors (black, grey, gold), but none had any reference to being an adhesive. Got on the forum and see that I should have been looking for Loctite Stick'n Seal which I will ck on tomorrow. Now George, when you split the push tube rubbers to install them around the push tubes, if I understand it that is when you applied the Stick'n Seal. Does it adhere quickly or does it have quite a bit of working time before it sets up? When you put these new rubbers on, did you place the two spring clamps back on to hold the rubbers together while they set up or did you use some other "clamp" to temporarily hold the rubbers together while they cured and later replace this clamp with the spring (same type of spring clamps that we used to see on heater hoses on our cars) clamps? Looks like I need to replace 3-4 of these to stop some leaks on mine. One mechanic said if you would remove the clamps and turn the rubbers 180 degrees that a lot of times that would stop a leak also.

[GAHorn]

Henkel owns Loctite brand..but no mention of Permatex in their long list of branded products.
Permatex, in 1990's bought some international lines of product from Loctite, but not the company. Permatex was acquired by ITW (Illinois Tool) just a few years ago.) As far as I know, Permatex and Loctite have never been the same products.

[GAHorn]

To be completely honest, the pics I showed of rubbers that I glued on the BENCH, not on the pushrod tube, were for a strength-test. I plan to cut the new rubber, seperate and apply the glue and let it cure for 10-30 minutes (like the directions state) then place it in position around a clean/dry tube, and close the rubber against itself. The bond is immediate. I will then apply the ring-clamps.

(Addendum: This promising experiment was an unfortunate failure due to the difficulty in applying sufficient pressure to completely close the rubber-seal around the in-situ pushrod tube. Additionally, the adhesive product has been discontinued by it's mfr. )

I have found that re-positioning the rubbers is a major cause of leaks because the rubber, once cooked-on the engine, is stuck, and then it tears when repositioned. If a rubber is torn, it might reduce the leak if the tear is positioned at the 12-o'clock position since the rubber only facilitates the oil draining back to the sump. (In fact, the very notion of searching for a simple way to replace a rubber without removing a cylinder stems from a time a few years back when a friend (who will remain nameless until I can find a way to take advantage of this story) assisted in re-installing a repaired cylinder. While I was running the engine and he was checking for leaks, he repositioned a rubber...which to this day has a small tear in it, and is one of my leaks that I plan to repair with this method. Moral: be very cautious about repositioning pushrod rubbers.

[Bruce Fenstermacher]

From the Permatex site:

The Permatex product line was expanded and the company continued to prosper. In 1972, the Permatex Company was sold to Loctite Corporation. The business was moved to Cleveland Ohio and integrated with the Woodhill Chemical Company.

It goes on to say Permatex was bought by private investors in 1999 later buying some Loctite markets.

I think it was during this 25 year period that lots of (but not all) Loctite and Peramtex products got cross mixed.

I have no idea if the Loctite product George is using can also be found as a Permatex product. I only brought this up because I've found that to be the case with other Loctite and Permatex products particularly in the thread locker and sleeve bearing glues.

[SUNDBY]

Speaking of oil leaks... It appears some of my leaks may come from the opposite end of the push rod tube; that is where the tube enters the head. I have been told there is some type of expander tool to tighten the tube in the cylinder head. any experence with this? Do tell?
Nels sundby

[Bruce Fenstermacher]

Yes the tubes are expanded after being inserted into the cylinder head. There is a tool that you insert to the right depth then turn in a tapered shaft which forces 3 ball bearings outward. You do this and turn the tool and the bearings expand the tube.

Here it is at ATS for $99. Maybe a local mechanic has one your could "rent" for a few bucks. http://www.aircraft-tool.com/shop/detai ... T_ID=4915A

You must remove the rocker arms and the pushrods in order to use the tool. Caution must be taken when removing the pushrods. Early tappet bodies did not have a snap ring at the end to keep the cup inside the body. Pulling on the tube which no doubt will have oil in it and that will cause the cup to stick to the end of the rod and be pulled.

Problem is you don't know you pulled it out till you spin the prop and the rest of the hydraulic body forces the cup and breaks the tappet body. Know your faced with splitting the case to replace the tappet.

At the very least when gently pulling the pushrods you should turn then to help break the suction. A better method is to shot a quick shot of shop air into the pushrod as you pull it. The air will blow the cup apart from the pushrod and keep it in place.

Oh if you KNOW you have all newer style tapped bodies, they all SHOULD have a C clip which holds the cup inside and in place so you can just pull away on the push rod. I pretend I don't have the C-clip all the time.

[170C]

What Bruce has told you will most likely fix your oil leak problem. It did mine One other word of caution, when expanding the push rod tube, be careful not to expand it too much or you can crack it or virtually cut the tube. Your mechanic will likely give you some direction on the tool's use. I don't know what cylinders you have, but when I did mine, I discovered that my ECI tubes were apparently slightly thicker walled and neither a borrowed tool nor two my mechanic had would fit into the tubes. He put one of the tools on his lathe and turned it down so it would fit inside the tube. Good luck!

[GAHorn]

Here's the tool, and where to get it, and how to use it:

Pushrod Tube Tool Image.jpg

Pushrod Tube Tool.pdf

The price may have changed. This is a ten-year old price sheet.
You can borrow mine if you pay Priority Mail ($5) both ways and leave a deposit equal to purchase price.

[SUNDBY]

Thank you George, I have one on order. El Reno is out of stock, Gibson had one. Nels