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914rat
I pulled my heads and will replace the tube seals was wondering if there is anything I should put on the seals besides some oil?
DanT
nope biggrin.gif
dr914@autoatlanta.com
QUOTE(914rat @ Apr 7 2010, 12:38 PM) *

I pulled my heads and will replace the tube seals was wondering if there is anything I should put on the seals besides some oil?



we use silicone grease when installing and nothing else. (except for the viton seals!)
914rat
Thanks biggrin.gif
URY914
agree.gif
Cap'n Krusty
I hope you didn't pull the heads just to replace the seals ...................

Be sure the bores on both ends are REALLY clean.

The Cap'n
realred914
get the holes the o-ring goes into very very clean. easy to do if your pulling a head anyway. but a bit more tricking if you replacing them on the car.

if on the car, do a steam clean before you start, then pull the tubes and seals then with a bright flash light and mirror, carefully inspect for zero dirt ALL AWAY AROUND the seal bore, THIS IS CRITICAL!!!!! make sure your tubes seal area is also perfect clean and still round also!!! the bores on teh engine case are hard to see up in there with engine in car, hence teh flashlihgt and mirror are needed. o-rings will not seal well if installed over dirt. you should be surgiacally clean when doing this

o-rings like to be lubed when installed, it prevents them from twisting and tearing, either which can make a BIG leak. I lube them with engine oil, but automotive greases should work fine too.

Once installed, you need to do the whole mirror flashlight routine again, this time makeing sure that the oring did not get pinched. You must look 360 degree all around the seal at teh engine case if you see ANY o-ring pertruding out over the ridge on the tube, you need to repair it. hence the light and mirror are needed.

oft one or more of the of the rings will get pinched. examine the seals as you push the tube in, if you see it starting to pinch and poke out, back off a little bit and with a blunt wooden or plastic stick tuck it back in, then contiune to push in the tube untill seated, then re-insepct. do not use metal pokers like a screw driver as they can easily damge the o-ring.

dont use glue or sealant

use of VITON tyep rubber is hgihly recommended, Viton is a high temp polymer that will out last the older style stock seals. it cost a bit more, as it is a hightech specail rubber, but it is well worth the price as it helps prevent doing it again soon!!!!!!!! headbang.gif


take your time, inspect , be supper clean, lube up, install tubes with slow even pressure, inspecting for potruding o-rigns as you push the tube in, and re-inspect when done, you only want to do this job ONCE!!!!!!
then you get to do a valve adjust!!!!!!! inspect your valve adjustment screw ends for pits and waer at this point, same for the valve stem ends. if youfind an adjsuter screw with a step worn in it, get a new one, elve your valve wont stay adjusted, and valve rotation may not happen. note for correct valve stem/adjuster screw contact, you want ot have good roations, by having them slightly offset, with nice smooth contact surfaces!!!!!
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Al Meredith
I use a "dingleberry" hone on the head to assure a clean surface for the Oring to seal. Put a little grease on the Oring so it rolls in , and use a flashlight to inspect the installation.
Jake Raby
I have applied them in the conventional manner as mentioned here, but have also applied various sealants to them during install.

In some applications I have found the necessity to use sealant and my choice for this is Loctite 565 as it remains flexible and is a super slippery Teflon based product.

I use this for engines that will be operated in very adverse conditions, or where the tube could become dislodged during operation, creating a leak. I have also used it as simply an added bit of insurance during the assembly of both street and race engines.

I have found this sealant to be VERY helpful when using fully synthetic oils that have a tendency to weep by the pushrod tube seals when installed as prescribed without sealant.

I did this to the engine in my 912E and after 160K miles its still bone dry and has used synthetic oil since day one, with as much as a 23,000 mile drain interval. I've never changed the oil in that engine at less than 10K miles and it still doesn't leak. The oil thats in it now has been there since 2008 :-) Bone Dry.
Mark Henry
I've also used used Jake's method and it works well.

I spin the tube as I install and the 565 makes it slip in.
I think it's when you cut the seal on install that causes a leak, the 565 may just be preventing (because it's slippy) the seal from being cut
914rat
QUOTE(Cap'n Krusty @ Apr 7 2010, 05:20 PM) *

I hope you didn't pull the heads just to replace the seals ...................

Be sure the bores on both ends are REALLY clean.

The Cap'n



Nope,pulled them because the car was running rough and after checking the carbs and ignition I went to adjust the valves and a rocker arm was broken.I pulled the head and found stuck valves by my local machine shop.Evidently the ethanol in the new gas causes the fuel to turn to maple syrup after 3 or 4 months.He says the last 2 years they have seen it a lot.The area behind the valve was like glue.Pulling the other head tonite and having them cleaned up.He said that if the car is going to sit for several months to use fuel stabilizer it's a must with this crappy gas we get now.He had to bang the valves out on #4.
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