Help - Search - Members - Calendar
Full Version: Push Rod Tube Seal Leak
914World.com > The 914 Forums > 914World Garage
collinvon
Looks like I found where all the oil has been coming from. I cleaned the engine as well as I could with a degreaser, ran it for 5 minutes at idle, and was able to spot a substantial leak coming out of the push rod tubes:
IPB Image

I'm going to tackle this project this weekend. I've found some good older articles that mention it can be done without dropping the engine, but might have to replace the seals on a couple without fully removing them.

I'm going to replace the valve cover gaskets, adjust the valves for the first time, and I'll being doing the first oil change since I've had it. I've heard Valvoline ZR1 20W-50 is a good oil to use, and I can find it locally. Thoughts?


Aside from ensuring I don't damage the seals on reinstallation, and thoroughly cleaning everything, anything else I should keep in mind, or try to tackle while I'm in there? Any other tips and tricks are much appreciated.

Thanks in advance for any feedback.
JawjaPorsche
Excellent oil. Get newer seals such as viton. It can stand the heat better.

http://www.autoatlanta.com/Porsche-914-Vit...l-Kit-srch.html
mark04usa
Be sure to clean the push rod tubes and the bores really well and lube the new seals with oil on installing. Some folks will tell you to use a sealant on the o-rings. This has been debated here several times. My vote is no sealant because of the expansion and contraction of our engines from cold to fully warm moves these seals in the bore.

You won't be able to fully remove all of the tubes and it is a tight area to work in. Be sure your car is well supported by safe stands. smash.gif
dr914@autoatlanta.com
it is a very nice filthy greasy mess to do, and will make you appreciate your 914 more once accomplishing it. Please make sure to check the valve adjusters for pock marks
iankarr
agree.gif
If you've never done pushrod tubes before, I'd recommend dropping the motor. There will be a fair amount of blind wrenching, cleaning and head scratching geometry and if you're unfamiliar with how it all goes together, you'll have an easier time and learn more with the engine out. It will also give you an opportunity to change the oil cooler seals, do a full cleaning, and see if there's anything else that needs attending to. Also, if the PO used a sealant in the bores, it will be difficult to fully clean them while under the car.

In addition to the viton seals, spring for a set of new tubes. They're not expensive and you'll know they're all round and not dented wink.gif.

Good luck and be safe!
collinvon
QUOTE(cuddy_k @ Jun 19 2019, 03:54 PM) *

agree.gif
If you've never done pushrod tubes before, I'd recommend dropping the motor. There will be a fair amount of blind wrenching, cleaning and head scratching geometry and if you're unfamiliar with how it all goes together, you'll have an easier time and learn more with the engine out. It will also give you an opportunity to change the oil cooler seals, do a full cleaning, and see if there's anything else that needs attending to. Also, if the PO used a sealant in the bores, it will be difficult to fully clean them while under the car.

In addition to the viton seals, spring for a set of new tubes. They're not expensive and you'll know they're all round and not dented wink.gif.

Good luck and be safe!

Thanks for the great info. I have some viton seals on the way. I'm hoping to avoid dropping the engine for another couple of months, if at all possible. I plan to drop the motor, change all the seals/wearable parts, and see if anything else needs repair/replacement this fall while I repair some hell hole rust spots.. I will definitely be replacing the tubes themselves this fall as well.

If I have too much trouble, it looks like it's not too terrible to get the engine out. Getting it back in the first time is what is a bit more intimidating to me.

That being said, if it can be done with the engine still in, what is the best product to clean everything up with in there?
iankarr
If you're under the car, don't use anything too mind altering. Mineral spirits is probably as hard core as I'd go.
Mark Henry
To do them without dropping the engine you can remove the shift rod, loosen or remove the clutch cable, etc, then undo the front mounts and drop the nose about 4-6" . PITA on jack stands but doable, I have a lift and use my tranny jack to do this.

I use Dow 55, it's a mil spec O-ring lube, I used to use liquid teflon or even oil, I don't like putting them in dry.
Heads off I use a 120g drill flap wheel to to clean the head bores, on a rebuild I also do this on the case bore, but not on a assembled engine. With some sandpaper or scotchbrite pad make sure the bore openings have no sharp edges. Everything spotless clean and degreased.
As I put the PR tube in I spin the tube 1/4- 1/3 turn as I install, this and cleaning up the bores is so you won't cut/nick the seal as you install.

Double check that the PR tube retaining springs sit correctly, Likely you'll have to use needle nose pliers to pull them out so both corners sit on the PR tube edge correctly.

Oil, you're in minnesota, cold spring/fall mornings, so I'd recommend 15w40.
collinvon
QUOTE(cuddy_k @ Jun 19 2019, 04:22 PM) *

If you're under the car, don't use anything too mind altering. Mineral spirits is probably as hard core as I'd go.

Sounds good. The more I think about it, the more I do just want to pull the engine and do everything right once. Seems to be easier to make sure I don't screw anything up if the engine is all the way out..
collinvon
QUOTE(Mark Henry @ Jun 19 2019, 04:33 PM) *

To do them without dropping the engine you can remove the shift rod, loosen or remove the clutch cable, etc, then undo the front mounts and drop the nose about 4-6" . PITA on jack stands but doable, I have a lift and use my tranny jack to do this.

I use Dow 55, it's a mil spec O-ring lube, I used to use liquid teflon or even oil, I don't like putting them in dry.
Heads off I use a 120g drill flap wheel to to clean the head bores, on a rebuild I also do this on the case bore, but not on a assembled engine. With some sandpaper or scotchbrite pad make sure the bore openings have no sharp edges. Everything spotless clean and degreased.
As I put the PR tube in I spin the tube 1/4- 1/3 turn as I install, this and cleaning up the bores is so you won't cut/nick the seal as you install.

Double check that the PR tube retaining springs sit correctly, Likely you'll have to use needle nose pliers to pull them out so both corners sit on the PR tube edge correctly.

Oil, you're in minnesota, cold spring/fall mornings, so I'd recommend 15w40.


Awesome, thank you for the tips. Sounds like pulling the engine might just be the way to go.
iankarr
It's not as intimidating as it sounds/seems. I made a video outlining the steps and the link is in my signature below.
collinvon
QUOTE(cuddy_k @ Jun 19 2019, 05:26 PM) *

It's not as intimidating as it sounds/seems. I made a video outlining the steps and the link is in my signature below.


That's a great video, I'm sure I'll be referencing it the entire time. Anything else I should check or replace while it's out? So far i'll be doing the following:

Replace push rod tubes/seals
Replace oil cooler gaskets
Oil Filter
Check oil sump filter (I ordered a new one JIC)
Replace valve cover gaskets
Adjust valves
914Toy
agree.gif
JawjaPorsche
Get valve cover gaskets from 914Rubber. They make thick ones and they don’t leak.

Also since you have to remove shifter rod, I would replace bushings.
iankarr
...and check to make sure the front main seal and pressure sender on top of the engine aren’t leaking. Glad you found the video helpful!
Superhawk996
QUOTE(collinvon @ Jun 19 2019, 06:03 PM) *

QUOTE(cuddy_k @ Jun 19 2019, 04:22 PM) *

If you're under the car, don't use anything too mind altering. Mineral spirits is probably as hard core as I'd go.

Sounds good. The more I think about it, the more I do just want to pull the engine and do everything right once. Seems to be easier to make sure I don't screw anything up if the engine is all the way out..


biggrin.gif good call beerchug.gif

porschetub
I've only ever changed one set with the motor out of the car (not a 914) and found the old ones were viton and covered in a red sealant,I couldn't buy replacements @ the time so I visited a friend who ran a Eaton Fluidpower franchise and we sized hydraulic grade orings to suit,I had no leaks,these orings have a higher temp rating than viton ,don't remember the hardness rating but we found ones that matched the originals.
My guy said never fit them dry,some sealer is ok on T1 seals but not on a T4 as there is movement as mentioned.
IronHillRestorations
I also clean the bores, inspect for nicks and gouges, and use a Scotchbrite pad to gently scuff them circumferentially. and clean again. I stuff a piece of lint free disposable cloth in the lifter bore to keep abrasive from getting in. I use a thin coating of Loctite 565 right before installation. It helps lubricate the O ring and seal them. I do one tube at a time.

I've seen some guys goop them up with RTV, but that's not a good idea as it limits the thermal movement and can cause leaks.

Make sure you get the retaining wire in correctly or you'll ruin the push rods and potentially kill your engine.
collinvon
QUOTE(IronHillRestorations @ Jun 20 2019, 07:02 AM) *

I also clean the bores, inspect for nicks and gouges, and use a Scotchbrite pad to gently scuff them circumferentially. and clean again. I stuff a piece of lint free disposable cloth in the lifter bore to keep abrasive from getting in. I use a thin coating of Loctite 565 right before installation. It helps lubricate the O ring and seal them. I do one tube at a time.

I've seen some guys goop them up with RTV, but that's not a good idea as it limits the thermal movement and can cause leaks.

Make sure you get the retaining wire in correctly or you'll ruin the push rods and potentially kill your engine.


Awesome, thanks for all of the info. Any tips on ensuring I get the retaining wire back in correctly?
IronHillRestorations
It's pretty straightforward, just be sure to see how it's in there (pics prior to disassembly help) and make sure it goes back in correctly.

It's basically held in the slot on the rocker shaft bracket by spring pressure, and keeps pressure on the end of the tube. In doing my first rebuild a few years ago (35) I mistakenly trapped the spring under the rocker shaft bracket and was fortunate to find the problem before it killed my engine.
collinvon
QUOTE(IronHillRestorations @ Jun 20 2019, 10:39 AM) *

It's pretty straightforward, just be sure to see how it's in there (pics prior to disassembly help) and make sure it goes back in correctly.

It's basically held in the slot on the rocker shaft bracket by spring pressure, and keeps pressure on the end of the tube. In doing my first rebuild a few years ago (35) I mistakenly trapped the spring under the rocker shaft bracket and was fortunate to find the problem before it killed my engine.

Sounds good! Thanks again for all the info. beerchug.gif
collinvon
Alright, so I was able to pull the motor this last weekend, and it really wasn't too bad at all.

I had a new set of DANSK push rod tubes come in today, one is pretty messed up on both ends:
IPB Image
IPB Image

So I'm hoping to be able to clean and reuse one that's already on there.

Has anyone used these before? I'm curious if they hold up well.

Second question: Do I have to remove them one cylinder at a time with said cylinder being at TDC?

And third question/finding:
I was trying to check my valve measurements before I pull the rockers, and it was either a miracle the car was running, or I am doing something incorrectly.
I was able to see the notch on the flywheel and the notch on the fan, both at the top of the engine and they lined up perfectly. I'm assuming that means I'm at either TDC for one or three. I had the distributor cap off as well, and when it was pointing to cylinder one, there was no play at all in the rockers for either intake or exhaust on cylinder one and I am unable to get a feeler gauge in there at all. There was play on cylinder 2 intake and cylinder 4 exhaust. Also worth noting, that there was no play at all on cylinder three either. Please correct me if I'm wrong, but it is my understanding that I should be able to adjust both intake and exhaust for cylinder one when it is TDC, and 2 intake and 4 exhaust at the same time?

iankarr
No, you don't need to be at TDC when you pull the tubes / rods. But definitely keep track of which rod is which, and it couldn't hurt to note the orientation as well.

Sucks about that damaged tube. The flanges aren't really critical, since only the O-rings contact the bore...but I'd be concerned that the tube is out of round. Good idea to just re-use the best of your old ones.

Yes, if the flywheel notch aligns with the case split and the fan mark is visible in the front notch, you should be at TDC on #1.

If you have chromoly pushrods, 'loose zero' would be normal. Just loose enough to spin the rod, but not enough to put in a feeler gauge.

As for the "Cap'ns method" of adjusting other valves when 1 is at TDC...it makes perfect sense, but I find it confusing when I'm under the car. It only saves a few revolutions of the flywheel and doing one at a time is easier to keep straight. Not worth it for me, but maybe for people who abbreviate the month "June" smile.gif
MarkV
I always use the Crusty method. Just seems easier to me.

http://www.914world.com/bbs2/index.php?showtopic=28758
collinvon
QUOTE(cuddy_k @ Jun 25 2019, 01:13 PM) *

No, you don't need to be at TDC when you pull the tubes / rods. But definitely keep track of which rod is which, and it couldn't hurt to note the orientation as well.

Sucks about that damaged tube. The flanges aren't really critical, since only the O-rings contact the bore...but I'd be concerned that the tube is out of round. Good idea to just re-use the best of your old ones.

Yes, if the flywheel notch aligns with the case split and the fan mark is visible in the front notch, you should be at TDC on #1.

If you have chromoly pushrods, 'loose zero' would be normal. Just loose enough to spin the rod, but not enough to put in a feeler gauge.

As for the "Cap'ns method" of adjusting other valves when 1 is at TDC...it makes perfect sense, but I find it confusing when I'm under the car. It only saves a few revolutions of the flywheel and doing one at a time is easier to keep straight. Not worth it for me, but maybe for people who abbreviate the month "June" smile.gif


Thanks again for the advice! Shouldn't I be able to check the current adjustments for cylinder one when it's at TDC? I guess that's where most of my confusion is at the moment.
collinvon
QUOTE(MarkV @ Jun 25 2019, 01:18 PM) *

I always use the Crusty method. Just seems easier to me.

http://www.914world.com/bbs2/index.php?showtopic=28758

Hey Mark,

Thanks for the link! As I mentioned to Cuddy, I don't have any clearance at all right now for cylinder 1 at TDC, which seems like a big issue because the tolerances are so small. However, the motor was running fairly well before I pulled it out.
IronHillRestorations
Just make sure you are on TDC#1 not #3. If the engine is on a stand, I do one set at a time, which requires more rotations of the crankshaft
Mcraneiowa
I currently have my engine out. Can the engine be placed on end as it would be easier to view everything since I don’t have an engine stand. Would it have any effect on lifters, etc. being on its end while replacing the tube seals. About ready to start this process, just a bit more grime to clean up!
isdyl
Hi - sorry to butt in with a quick question, but I'm just fixing a leak at the moment and am a bit stuck. I thought I was just going to change the tube seals, but have found one tube has a hole in it! It's one that won't slide out fully annoyingly, so does this mean I have to take the engine out please?? I really hope not. Is there another option like maybe lowering the engine a bit somehow?
Regards, Dylan
iankarr
If that tube has a hole in it anyway, maybe just bend it till it comes free?

Also. @ironhillrestorations is right...When you think you're at #1 TDC, pull the distributor cap and ensure you're pointing to the #1 terminal. If you're at #3, you need to go round again.

@Mcraneiowa Way easier to work on the engine when it's on a stand. If you tilt it on its side be prepared for an oily mess. You can get a stand at HF cheep and a yoke from this guy...
https://www.thesamba.com/vw//classifieds/de...l.php?id=606308
isdyl
Thanks but I still need to get a new tube back in. Although I've bought a new set of tubes, I I'm considering repairing the hole in the tube now to avoid moving the engine. Does anyone know what temperature these tubes get to please?
Thanks
maj75
The tubes are drain back routes for oil from the head. If you rotate that tube so that the hole is at the top, no oil should leak out. Maybe some oil vapor, condensation. Should get you by until you can pull the motor.
ndfrigi
If you just want to replace one tube for now, I think you can lower the rear tranny by placing a floor jack to support the middle between engine and tranny (under the flywheel area) then loosen the bolts of both side of the engine mount bar by the engine support console and also loosen or unbolt tranny mount so you can lower the rear tranny until you get the tube out away from the suspension console mount.

Or place one floor jack in the middle of the mount bar and one floor jack in the middle of tranny. Just make sure to be very careful when you start lowering the rear tranny and not damaging the engine mount bar bolts. I’m sure you get the idea with this.
ClayPerrine
If you put a floor jack under the engine crossbar, then remove the bolt holding that side of said crossbar to the chassis, you should be able to drop that side of the motor down far enough to get the pushrod tube out of the head.

You may need to loosen the other side of the crossbar to get enough movement.


Good luck!

Clay
isdyl
Thank you all - I'll give it a go!
Regards, Dylan
isdyl
Hi, I've changed one tube and repaired the hole in the other with JB Weld Extreme Heat. I think there's a fair chance it won't last long but I'm just going try it. I'm just struggling with this funny wire retainer. Is there a diagram somewhere of how it should go please? It was in the wrong place previously and has damaged my push rods.

Click to view attachment
IronHillRestorations
Sorry, I don't have pics. The slot in the rocker shaft retainers goes to the bottom and that's where the upper bends of the retaining wire goes, the lower bends go against the end of the push rod tube. You have to put the rocker shafts in first and then the wire.
isdyl
Ah, ok thanks - I'll put the rocker shafts in and hopefully it will be clearer. That's great.
Regards, Dylan

QUOTE(IronHillRestorations @ Dec 14 2020, 12:51 PM) *

Sorry, I don't have pics. The slot in the rocker shaft retainers goes to the bottom and that's where the upper bends of the retaining wire goes, the lower bends go against the end of the push rod tube. You have to put the rocker shafts in first and then the wire.

isdyl
Ok I think I got it in correctly. It's quite tricky because of the access but your description was actually quite good thanks. I found it's important to get the spring against the tube ends first and then bend into the slots. If the spring goes down the tube by accident it's quite hard to bend into the slots anyway.
The leak is now just from the cover gasket!

QUOTE(isdyl @ Dec 14 2020, 12:59 PM) *

Ah, ok thanks - I'll put the rocker shafts in and hopefully it will be clearer. That's great.
Regards, Dylan

QUOTE(IronHillRestorations @ Dec 14 2020, 12:51 PM) *

Sorry, I don't have pics. The slot in the rocker shaft retainers goes to the bottom and that's where the upper bends of the retaining wire goes, the lower bends go against the end of the push rod tube. You have to put the rocker shafts in first and then the wire.


This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2024 Invision Power Services, Inc.