Pushrod tube seals

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Mulcheese
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Location: Maple Grove, Mn
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Pushrod tube seals

Post by Mulcheese » Sat May 02, 2015 5:34 pm

I started the annual check over after the winter storage. The same process as every year. Do an oil change, and general inspection of everything in the general vicinity. Last year I noticed a bit of oil leakage from the pushrod seals. Interesting since I replaced them with the good Vitron from BD. This year I noticed a much more accelerated leak from a seal. These seals are two seasons old. What did I miss? Why should they leak? Did I miss something on how to seat them? There isn't a special Trick to install, is there? The tubes were not dented or damaged on the ends.

What should io check for? Is there something that I should do different?

80* here today and driving the van with the windows down. Feels awesome. Almost a true summer!!!!!!!!!!!
"attending to things in the moment with curiosity and acceptance."
____________________
82 Vanagon Westy - aka: Honey Badger - "cause she just dont give a ...."

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SlowLane
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Re: Pushrod tube seals

Post by SlowLane » Sun May 03, 2015 9:35 am

Mulcheese wrote: What did I miss? Why should they leak? Did I miss something on how to seat them? There isn't a special Trick to install, is there? The tubes were not dented or damaged on the ends.
Well, there is the special trick of making sure the wire retainers are correctly installed, with the flat parts bearing against the ends of the tubes, not nestled inside the tubes.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: Pushrod tube seals

Post by Amskeptic » Mon May 04, 2015 1:11 pm

Mulcheese wrote: This year I noticed a much more accelerated leak from a seal. These seals are two seasons old. What did I miss? Why should they leak? Did I miss something on how to seat them?
Yes.

You want nice push rod tubes with no little smashed spots where someone tried to hammer them in.

You want clean bores in the crankcase and the cylinder head. Clean, smooth, no crud.

You want the serpentine springs in place.

These brown seals can nick very easily if the edges of the bores are too sharp and you don't get a dead-on alignment as you push the tube home.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Mulcheese
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Re: Pushrod tube seals

Post by Mulcheese » Wed May 06, 2015 7:02 am

Amskeptic wrote:
Mulcheese wrote: This year I noticed a much more accelerated leak from a seal. These seals are two seasons old. What did I miss? Why should they leak? Did I miss something on how to seat them?


You want nice push rod tubes with no little smashed spots where someone tried to hammer them in.

You want clean bores in the crankcase and the cylinder head. Clean, smooth, no crud.

You want the serpentine springs in place.

These brown seals can nick very easily if the edges of the bores are too sharp and you don't get a dead-on alignment as you push the tube home.
Colin
I was aware of these issues upon installation. I tried very carefully to clean, watch bores, and not smash. Well I may need to remove the bad ones and install new. I have read of many issues that follow installation and I thought that I covered my butt, but i guess not. time to get some new.
"attending to things in the moment with curiosity and acceptance."
____________________
82 Vanagon Westy - aka: Honey Badger - "cause she just dont give a ...."

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Amskeptic
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Re: Pushrod tube seals

Post by Amskeptic » Thu May 07, 2015 1:21 pm

Mulcheese wrote:[I have read of many issues that follow installation and I thought that I covered my butt, but i guess not. time to get some new.
A razor blade rake of the cylinder head bores to create a softer chamfered edge is an option. You clean nicely when done with the razor blade . . . :blackeye:

I have never had a push rod tube leak, except after broiling the little o rings into petrified mummies in Death Valley and then going into the cold northeast. Let us know of your Most Victorious Success.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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MountainPrana
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Re: Pushrod tube seals

Post by MountainPrana » Wed Jun 01, 2016 9:56 pm

Mulcheese wrote:There isn't a special Trick to install, is there? The tubes were not dented or damaged on the ends.
I know it's been a minute but I was wondering how your install went? Any leaks?
Amskeptic wrote:I have never had a push rod tube leak, except...
I am hoping for the same (no leaks) and have one quick question. Should I put moly grease on the seals when I install? I will have spent about 3-4 hours on cleaning the white silicon off from the PM (previous mechanic) and am hoping for a better solution.
Amskeptic wrote:You want nice push rod tubes with no little smashed spots where someone tried to hammer them in.
Looks like I'll have to replace 2 of the push rod tubes.
Amskeptic wrote:You want clean bores in the crankcase and the cylinder head. Clean, smooth, no crud.
I got this part covered:

Image
Image

Tim

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MountainPrana
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Re: Pushrod tube seals

Post by MountainPrana » Thu Jun 02, 2016 9:58 am

Ok, found some good info here: Newly Rebuilt Engine Questions 1980 Vanagon
SlowLane wrote:
cegammel wrote: 1) 3 of my rod tubes are drip-drip-dripping. On my last partial rebuild, I put them in dry with no leaks. This time, I put some white grease around them, and they drip like sieves. Is there any easy fix, or just pull the tubes and replace the rings?
Pulling the tubes is the easy fix (considering the ease of doing so on a T4 compared to a T1).
  • Use Viton rings
  • inspect and remedy any burrs or rough patches in the case and head bores
  • inspect and remedy any dents or irregularities in the tubes where the o-rings sit. New tubes aren't that expensive, so consider replacement if yours are looking ratty
  • use just clean engine oil for assembly
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  • gently use an appropriately-sized socket to seat the tubes during assembly
  • last, but definitely not least, make sure your spring retainers are correctly installed with the flat bits resting on the ends of the pushrod tubes, not sitting inside the tubes. The proper positioning of the retainers is essential to keep the tubes from creeping out of the case bores as the engine expands and contracts.
Tim

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Mulcheese
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Re: Pushrod tube seals

Post by Mulcheese » Fri Jun 03, 2016 9:52 am

MountainPrana I am happy to report that I do not have any leaks. What I originally thought was a push rod leak was the head leaking. It was dripping down on to the tubes. I never thought that the head would leak in that manner but I will have to wait for the rebuild to fix this one.
"attending to things in the moment with curiosity and acceptance."
____________________
82 Vanagon Westy - aka: Honey Badger - "cause she just dont give a ...."

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SlowLane
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Re: Pushrod tube seals

Post by SlowLane » Fri Jun 03, 2016 5:18 pm

Amskeptic wrote: A razor blade rake of the cylinder head bores to create a softer chamfered edge is an option.
This reminds me that the AMC heads I installed had some sharp edges in the area around the pushrod tube bores where the machine tool stopped boring the, er, bores. These sharp edges made it disgustingly easy to cut the o-rings, even while being very careful. Since there was no reason to have those sharp edges, I rounded them off with a jeweller's file.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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MountainPrana
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Re: Pushrod tube seals

Post by MountainPrana » Sun Jun 05, 2016 5:19 am

Just waiting on a few new push rod tubes but it's looking good so far. Glad to hear the process turned out well for you Mulcheese. I have to pull the motor to fix the front main oil seal which is leaking down through the Bell Housing, I'll be happy to get the oil leaks taken care of!
SlowLane wrote:This reminds me that the AMC heads I installed had some sharp edges in the area around the pushrod tube bores where the machine tool stopped boring the, er, bores.
Man the OEM VW heads seemed sharp enough, I can't imagine. Luckily I haven't run into any problems with the four that I have installed already. Although this little guy seems to be getting braver by the day.

Image

Tim

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