Push Rod Tube Seals (how to) ?'s

[Moonunit]

1980 Westy "type" new to me. Leaking onto exhaust manifold, pass side. The "bible" appears to still be in greek to me, (proly cause there's no damn index!). Tried the search without any real luck.

I'm a half decent wrench, have lot's of tools and access to a full shop and lift on occasion. A link or step by step would sure be appreciated. Haven't really tackled VW's although I also have a 72 Camper, I've always paid someone else to work on it. Time for me to learn

[Moonunit]

OK, I found this on type2.com.

"Pushrod Tube Oil Seals

Leaky pushrod tube oil seals are a common cause of oil leaks on the VW air-cooled engines. To fix the leak, you have to remove the pushrod tubes and replace the seals on both ends.

It's not a technically difficult task, but it is time-consuming and will try your patience. It will be easier to do the job with the rear wheels removed.

NOTE:This procedure applies only to the Type 4 engine. To replace the pushrod tube oil seals on a Type 1 engine is much more involved, since the cylinder heads have to come off. "

So, is this considered a type 1 or type 4? If it's a type 4 I think I've found what I'm looking for.

[tencentlife]

You have a T4, so you're in luck. The pushrod tube seals are a very easy job, so far as lying on your back with dirt in your eyes can be easy. And while you're at it you can check out your valves, learn how to preload the hydraulic lifters, and especially look for one of the notorious T4 "dropped seats".

But all that is a bit more than would be realistic to type out instructions for, at least all at once. You should get the official factory manual, the Bentley book, and go over the procedures, then maybe ask questions here where you need clarification or more info. The book isn't big on step by step procedure, but has good exploded drawings and specifications. The Haynes manual is structured in a step by step format, but doesn't tend to have such good illustrations.

http://tech.bentleypublishers.com

Haynes manuals are much cheaper and they have them at AutoZone, Pep Boys, most other AP stores.

[Moonunit]

Thanks very much for your reply The Bentley book is the "bible" I was reffering to. If you are well versed with it, and you get a chance, perhaps you might be able to point me to where I can go in the book. I have to admit I became frustrated with it just trying to find info on what I was looking for.

I've already cleaned the area quite well so the dirt in the eyes won't be as much of a problem when I get started, hopefully today. Thanks again.

[tencentlife]

Good, you have the book. I missed your reference to the bible, thought maybe you were a faith-based technician.

Look at:
p.15.2 expoded view
15.3 fig. 1 & 3
15.6 right column

You'll need to know how to find top-dead-center on each cylinder to do the valve adjustment later (p.13.9 fig. 5 for cyl.#1). The book doesn't seem to have a basic engine orientation diagram, so ask if you don't know how to move to the other cyl. numbers.

You'll open both valve covers and remove both sets of rocker gear (2 per side) and the pushrod tube retaining clips and pushrods. Mark or store them in a way that you can put them back in their original locations. Inverted eggboxes make a nice rack for holding the pushrods in order. It's OK to mix up the tubes, though.

The tubes pop right out. This is where the T4 is easy. You can't do this on any other of the boxer engines. If they're stuck, use a round-jawed visegrip and set it to VERY GENTLY grip the outside of the tube just inboard of the taper, and give the pliers a tap with a mallet. Careful not to dent the tubes, it is easy to do.

Renew the o-rings, two different sizes inboard and outboard by color. VW wants them lightly oiled and installed into the clean bores. You can use a light NON-HARDENING rubber cement sealer like Gascacinch instead of oiling them, but never use any silicone type sealers. Silicone will squeeze out, the flashings will harden and come loose and can clog up your oil pump pickup screen. Hardening sealers like Aviaton Form-a-Gasket or Indian Head will shorten the life of the o-rings. If in doubt, just use your motor oil and get the grooves and bores very clean.

The tubes with fresh o-rings go back in, and with a little push they pop back into position. Before you do, take a close look at one of the hydraulic lifters in the case. Take a pushrod and feel how it can catch inside the rim of the lifter, and how you can budge it a little so it pops into the shiny socket in the very center of the lifter, which is where it needs to end up. Having a feel for this will help when you reinstall the rocker gear.

Before you do, get a straightedge, like a 1 foot steel ruler, and lay it across the tops of the valve stems to see if any stick out further than the others. If any are proud by more than 1 or 2 mm then you may have a valve seat "dropping", or getting mashed into the cylinder head casting by heat and the hammering of the spring pressure. This is a classic problem with T4 heads. If you think this is the case, plan on doing a valve job soon, before the seat comes loose and damages the engine internals.

Reinstall the rockers one pair at a time, making sure that the pushrod is seated in the center of the lifters, which you now can't see very well, so it's good to have gotten a feel for it. You can lever the inside end upward if needed with a wide screwdriver put just into the pushrod tube opening, but be very gentle. Do it with your fingers if you can. Torque the rocker nuts to 20 ft.lb. (EDITED: the torque should be 11 ft.lb. ) Reinstall the tube retaining clips like the picture in the book.

On 15.6 is the procedure to preload the lifters. This is controversial, and there is an endless unsolveable discussion as to whether preload is necessary or even advisable. I haven't had much problem with these lifters, so I always preload them 1.5 or 2 turns. It is not an exact adjustment at all. If you are between 1 and 2 turns it'll all be OK. The reasons why are way too involved for me to even begin to talk about in this already too-long post.

Use new valve cover gaskets, the cork ones. For solid lifter motors that need 3000 mi. valve adjustments, I always coat the gaskets with wheelbearing grease and stick them into the covers. The grease keeps them supple and good for two or three adjustments without getting brittle. For a hydro lifter motor, where you won't be in there so often, I Gascacinch them into the covers, but coat the other surface with grease. That seems to work well. The gasket doesn't dry out, but it won't creep under the cover rim. The non-hardening cement makes it easy to peel them away from the covers when it is time for new ones.

Have fun!

[Moonunit]

Yup, that's the area of the manual I was in. The diagrams are nice, but explanation is nearly non existant. My initial thought was, oh, the heads gotta come off to do it I read a bunch of posts before joining the forum and ran across one that just touched on the type 4 I guess, and got a glimmer of hope.

THANK YOU so much for taking the time to walk me through. I generally don't get into internals without direct supervision, but with the info you've provided, I think I'll give it a whirl.

Off for parts, the cork gaskets and Porche seals. I'll let you know how it turns out

[tencentlife]

It's my pleasure. I have time, and I like to help anyone learn. Good luck, take your time, and don't hesitate to ask questions. There's a wealth of helpful folks around here.

[Moonunit]

OK, I'm doing it now. One side at a time, in the driveway. I've got all the hardware off and properly lined up. Getting the forward tube out was tricky cause of the shielding but I got it. I'm going to use Permatex High heat thread sealant, non silicone, saw it in another post (formerly a locktite product).

I'm going one at a time. Putting the first one back in a few. One question. Since nothing has changed with the rocker settings why do I need to readjust them after reinstalling? They will (should be exactly the same as before). The other ones look easy. I should be checking back in an hour or so, before resetting the rockers or sealing her back up. Thanks.

Redid a whole C4 corvette drivetrain (not the rebulid) into a High 11's street car on my own with help from the corvetteforum and others, I love these forums!

[Moonunit]

OK. everything is back in correctly. I'm ready to torque the rockers back down to 20 ft lbs. The valves were nice and even with a straight edge. Two of the four tubes went in by hand fairly easily. I used a socket and a few light hammer taps to drift the other two. the seals looked good as far as I can tell. Did a lot of additional cleaning in the area.

I got an old Motor Manual from a buddy while I was running parts. It has some additional proceedure info not in the "bible" that I could find. Firing order and so forth. His AllData only go's back to 82 and didn't look like any help even for this proceedure in there. I got mechanic buddies, but they hate VW's especailly the vans so I'm kinda on my own with you guys They don't care for non stock Vettes either

Now I'm oh so tempted to throw on the valve cover and see if she leaks or not. Of course bypassing the valve adjustment and preloading the lifters. I figure if needed I can adjust all the valves at onece after I complete the other side. Can I, Can I Can I?

[tencentlife]

You're exactly right, by putting the rockers back in their original positions you don't really need to reset the valves,especially since hydraulics are so forgiving of the basic setting. I just threw that in because you should be familiar with the procedure, since even though they are self-adjusting it's a good practice to check them every so often, maybe 20- or 30-thousand miles. You can skip it for now.

But study the book that has the cylinder numbers and wire positions on the distrib. All flat four VW's are the same this way, so you can memorize the layout and it will help if you need to ask questions on forums like this.

Im not familiar with that sealant, but as long as it is non-hardening and doesn't squeeze out flashing of excess sealant it should be OK. The sealant shouldn't harden because these seals kind of float in the bores and need to be flexible. The engine is long in layout and expands quite a bit as it heats up.

Good report on the valves, that's nice to know you don't need to worry about a valve job too soon.

One last warning. Make sure to HAND CRANK the motor thru several full cycles to be sure you've got all the inner pushrod ends seated in the lifters. If any are out of place you'll hear a nice loud SNAP as they pop in, after which everything is OK. I wouldn't want that to happen at running speed, though, something could be damaged. Also if any aren't seated it's possible a piston could hit a valve on the overlap. You'll definitely want to feel that out first before firing it up.

[Moonunit]

Well, I got lucky, and, unlucky. All the pushrods were in place as I fired the engine before reading your last post. A little rattle for about 30 seconds which I suspect is normal. Ran the motor for about an hour revving now and then but no test drive. NO LEAKS FROM THE SEALS

Now for the unlucky (normal for me), if it ain't done [at least twice] it wasn't done by me. I think I may have understood your step by step post thinking that rocker nuts was rocker assembly nuts I got one or two to torque to about 14 ft lbs. The others never did and I started to get suspicious that i was stripping something. Well I was right.

I decided to go to my friends shop and try a different torque wrench today. When I went to take the nuts off one side that I was particularly suspicious of they wouldn't come off but the studs came out of the head! Well, then I couldn't get the nuts off the studs without some heroic efforts I won't go into. Suffice it to say the studs were toast. Fortunately the head side was all good.

Unforutnutely, pretty much a dealer item, not in stock of course. Five days out. The nearest ones in stock were in Michigan or something. The hunt on, no parts houses have em. Looking for used now, I'm 15 mi from home clogging up the buddy's shop + a ride home Finally, as I had just about given up a call came in from a place that was to busy to talk to me and I didn't expect to hear back from. How many do you need? Two. We got two. Need the nuts too. K we got em.

Long story short[ened], big traffic, but I wraped it up at about 5:30 PM while my buddy waited graciously to go home. While I was trying to find the studs I was able to determine that the torque for these is 11ft lb which the guy that sold me the studs made sure to advise me in no uncertan terms without my ever telling him why I needed the studs

Livin' and learnin' over and over and over again. Thanks again for your help tencent

[tencentlife]

Well, my bad. I didn't look up the torque on those studs, just threw out a standard torque for an M8 fastener which is 18 ft.lb., rounded to 20 ( I use a dial torque wrench and you can't see the difference betw. 18 & 20 ). But you're right, the bible has 11. Maybe those are M7's, that would explain it. I used to build them, but I haven't been into one of those T4's in ages. And something like that was just tightened by feel. Now I kind of remember them using a thinner stud there.....

Sorry it caused you trouble. But then, there's that saying about free advice: it's worth what you paid for it. That'll remind me to cross-check things people tell me.

Anyway, you're on the road, and free of those stinky leaks. That's cooly cool. Enjoy!

[Moonunit]

[tencentlife]

Well, when I'm writing my little screeds here I usually have the book open nearby so I can make sure I'm not giving anyone the wrong info, but I just went from memory on that one, so shame on me, too.

[moosie982]

Is this procedure the same for an early 83, (aircooled). Thanks,,,Peace,,Moosie

[tencentlife]

Yep. Have at it, Moosie.

[tencentlife]

Oh, Moosie, or anyone else who might use the procedure above but haven't read the rest of this thread, don't forget to only torque the rocker arms' retaining nuts to 11 ft.lb.

[moosie982]

o.k. thanks for the reply, havent crawled under it yet to see the actual leak, only that I can smell it and can see that the heat exchanger is oil stained, maybe it'll be just the V.C. gasket,,,,,,nah, not with my luck. It dont seem likke to bad of a detail if it is those push rod tube seals. Peace,,,Moosie

[tencentlife]

I thought this board wouldn't let me edit after a reply has been posted, but I went ahead and edited the procedure to correct the torque setting.

[peruvian]

I just replaced a bent pushrod and after turning over the engine, it wouldn't start. Took the valve cover back off, pulled out the new push rod and it's bent

Called Ken at Van-Again for a new pushrod and he mentioned it could be a stuck valve. Suggested hitting it with a hammer to check (yikes!). Can someone provide insight into how I diagnose and repair a stuck valve? Never had an overheating problem and the heads were repaired (due to coolant leak) 2 years ago.

Thanks.