Changing Pushrod Seals , need help

[tyler]

Ive never had to change pushrod tube seals, I have a very bad leak is it hell putting in new pushrod seals???

Ive had mechanics do it for me in the past how do they replace the seals without removing the heads??

Please, please email me: Snakes2U@aol.com

[BenI]

Its an easy job:

1)Jack up car on side your are repairing-use a jack stand-I like placing it on the rear suspension member right in front of the rear wheel.

2)Remove valve cover
3)Turn engine over (put it in 5th gear, one wheel should be in the air, the other on the ground, release E-brake and turn wheel in air) so that the springs for the vlaves youre working on are relaxed, i.e no pressure from rockers on valves
4)Remove 2 nuts securing rocker assembly for the cylinder
5)Pull off rocker assembly
i)hold assembly at either end of rocker shaft
ii)when assembly is off, put q-tips (or anything else that works) in rocker assembly stud holes to keep the rocker springs from expanding
iii)keep rockers organized and clean(and everything else)
6)Now you can either remove push rods and pull the tubes out a little, or leave push rods in and pull the tubes out a little-the tubes just pull toward the outside of the car
7)You can actually remove the entire tube w/o taking pushrods out-but keep everthing clean!
8)Remove old o-rings from tubes
9)CLean tube ends and mating surfaces with denatured alcohol
10)apply thin layer of high-temp (orange or grey in color) gasket maker (I think permatex, comes in a tube) to new o-rings and put them on tubes.
11) Reassemble everything-tubes will pop into place-you will be able to feel when they are in


Ive done this several times before-its easier and faster than it may seem. Give the gasket compound enough time to cure, and they will not leak. Also, if you ever have to do it again, the gasket compound cleans right off with alcohol and remains flexible-its good stuff.

Good luck

email if unclear: ihas@colorado.edu

[Conrad W Peden]

Don't forget to put in new valve cover gaskets while your at it.

They are cheap and should be done at the same time.

------------------
CWP/VIR
72 914 L20E in rusto.
73 914 L20E 2.0L in resto.
http://members.rennlist.com/a914lover

[TimW]

Here is a how-to on doing the job: http://www.914fan.net/pushrod_tubes.html.

It's just a rehash of what's above, but it gives you a different perspective on the task.

Although I would disagree with the article on a few points:

- Don't use tools on the push rod tubes, as tempting as it may be. They crush very easily.

- DO use permatex. The article says don't, BenI says do, I say do. I've had good success using it.

- I just relax the rocker by feel. The article does it by TDC, etc. Both will work, one will take longer.

Tim



[This message has been edited by TimW (edited 01-18-2001).]

[Bleyseng]

I disagree with using a gasket compound to seal the seals. The rubber O rings are designed to float and seal as the engine expands. If you anchor the pushrod tubes with sealent then thats where you get the leaks later on. Use Viton rubber seals and clean the engine case bores, heads bores and the pushrods super clean and you won't have any problems with the tubes leaking. The trick is seating the tubes with new seals. Apply a little 30wt onto the seals then slowly rotate the tubes until they seat home. You don't want to pinch the seals anywhere! After reassembling the rocker assembly, make sure the funny spring is seated onto the pushrods correctly. Otherwise, the tubes can float out of their seats and leak bigtime! Also, replace any tubes that are bent, dinged, or don't clean up perfect. The tubes are cheap! Make sure when you put the valve covers back on that they seat correctly too. It very easy to install them incorrectly and then it looks like the pushrods tubes are leaking.
If you do remove the pushrods, make sure they go back into the same lifters! When I have done this job, I take a cardboard box and mark it with the cyl numbers, #1, #2...and punch holes to push the pushrods into to keep everything in order.
Just my .02
Geoff
76 914 2.0L

[John Rogers]

I used to use Permatex on my old VW bus on the seals and they would last just about a year and start to leak which reminded me to adjust the valves. I use a hi temp synthetic grease on the ones in my race motor as it does not have the springs due to roller rockers and the grease allows the o-rings to move a bit without leaking. I agree with the use of the vitron hi temp o-rings. As a last item, make sure the push rod tubes seat in the lifters correctly and do a careful valve adjustment. I have seen people that just bolted the rocker assembly back on and had to do a valve adjustment the next day! Good luck.

[Dave at Pelican Parts]

Did they use it on the outer end only, or on both inner and outer ends? The "sliding" function could still work if only one end was "gooped" in.

--DD

[Bleyseng]

I figure if VW/Porsche built the motors without sealant they must know something. The motors I have built didn't leak a drop at the tube seals. I have seen lots of people use sealant. Some of them also throw out half the cooling tin, rip out the FI cause it's crap on and on.....
Geoff

[rich]

I used red RTV. I sprayed the seals with carb cleaner. While they were still wet, I slid the tubes in place. After I installed the tubes I wiped things clean and dry. I applied the goop to the outside of the tubes only. It cures like soft rubber and is more flexible than the "O" rings. I ran my motor for 3 summers (outside storage in the snow for two of three winters) No leaks.

[roadtrp204]

Once you apply sealant, you are stuck using it. You will never be able to remove all of it unless you pull the engine out and have a clear view of what you are doing.

As stated by permatex, RTV is a gasket maker, to be used in place of a gasket. Companies like Cheverolet use it as a cheap way to seal valve covers and tranny pans. It is also to be completely cured before the part is installed. Having it blob inside an engine (valve train with small oil passages) is a dangerous thing to do.

O-rings are one of the best sealing devices. Using ones that meet the temperature requirement and the right lubrication on installation should provide a long leak free service life.

------------------
Chris
75 914 2.0L

[Pritchard]

I battled leaking pushrod tube seals for years. I replaced the seals/O-rings three times in three years and still had leaks. I even tried the red RTV idea. It worked pretty well. Then I had some head work done and replaced the pushrod tubes (mine were dinged up) and seals with the Vitron(sp?) seals (ordered from Pelican). I have had absolutely no oil leaks from the O-rings in the past 14 months.

The combination of new tubes and the PROPER seals made the difference for me.

Pritchard

[BenI]

You don't have to use the compound on the o-rings, but you know the cylinders are iron and the tubes steel, so they expand and contract basically the same way. The compound is very flexible, and if there is slippage due to expansiopn, the compound isnt going to stop it. Its up to you.

[TimW]

"New pushrod tube o-rings are part of every gasket set. Apply coat of Permatex 3H or RTV silicone sealer when installing to prevent oil leaks." p.137 How to Rebuild Your Volkswagen Air-Cooled Engine by Tom Wilson.

[TimW]

woops.

[This message has been edited by TimW (edited 05-23-2001).]

[TimW]

I talked to a pro VW engine rebuilder who said he NEVER uses anything but good quality O-rings. Maybe I’ll try that next time.

[guards73/2.0]

Just finished a top end rebuild and am horrified at the thought of the Freddie Krueger-like return of puhron tbe leaks.
I did the agonizing job of replacing the seals in the car last summer and that helped, but did not solve my problem. When I installed NEW seals on NEW pushrod tubes into NEW heads they felt MUCH tighterwhen they went into the lifter bores...so I banged 'em in...and when I filled the crankcase and looked underneath....ONE WAS LEAKING! My long, incredulous gaze revealed
the cause...I'd whacked them in too far into the lifter bores, and not enough tube was sticking into the heads I ( I could actually see the seals in the heads from underneath), so I tapped on the inner head-side flanges with a screwdriver to move the tubes and that stopped the leak. I think that the "New tubes, new seals" theory sounds best. I HATE
RTV! It's ugly and seldom works. I just used the 30 WT. So we'll see when I fire it up. more in the head direction

Originally posted by Pritchard:
I battled leaking pushrod tube seals for years. I replaced the seals/O-rings three times in three years and still had leaks. I even tried the red RTV idea. It worked pretty well. Then I had some head work done and replaced the pushrod tubes (mine were dinged up) and seals with the Vitron(sp?) seals (ordered from Pelican). I have had absolutely no oil leaks from the O-rings in the past 14 months.

The combination of new tubes and the PROPER seals made the difference for me.

Pritchard

[JP Noonan]

On the two motors I re-sealed without doing any head or motor work, I didn't use sealents, both are dry 4 (?) years later.

What I did do was to completely remove the valve train and tubes (motors were out of the car. Then stuff the lifter bores with shop towels. Then I used carb cleaner and a "Scotch-brite" pad on the lifter side and head side where the O-rings sit. Used German seals, oiled them, then used a larger 1/2 drive socket and extension with hand force to drive them in. Had to push on the socket and also rotate them to get them in.

Biggest mistake you can do is to used Brazilian seals ANYWHERE on your engine.

[SteveStromberg]

When installing the tubes put a light coating of Curil K2 on the seals. Steve

[J P Stein]

Silicone GREASE is the hot ticket on similar applications (oil return tubes) on the 911 motors. Any O ring, for that matter. They do need to move around. It withstands the temps and won't be washed out by oil.

I've been smoking for 35 years......that don't mean it's the smart thing to do....

JPIII

[Jim Smolka]

Oh an air cooled motor, I would never use RTV. The problem with RTV is that it becomes somewhat hard and is likely to break off and go into the oil. NOT A GOOD THING


I recommend either Silicon Paste or Loctite 518. Both are a little expensive, but well worth the extra $$.

I use the Silicon Paste on O-Rings and the 518 on gasket surfaces.

Just my $0.03 worth.