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Posted by: pcdarks Jan 22 2021, 10:42 AM

I'm getting ready to put my 1.7 back together and am wondering what you people do to insure that the push rod tubes don't leak. From what I saw taking it apart this is where most of my leaks came from. Is it possible? or were the tubes designed by the British? thanks.

Posted by: Superhawk996 Jan 22 2021, 10:45 AM

They all leak eventually. Viton seals are the best bet long term.

In my experience, I've had decent success with silicone grease O-ring lubricant from Dow Corning. Helps avoid nicking the o-rings on install and provides a little lubrication to account for thermal expansion contraction.

RTV is a no-go IMHO. I've never seen that work.

Posted by: wattele Jan 22 2021, 10:51 AM

I had my push rod tubes powder coated.
After powder coating they are a little ticker this together with new seals I have no leaks after 8000 Miles.

Succes Willy

Posted by: DRPHIL914 Jan 22 2021, 10:52 AM

for me the third time was the charm no leaks for 2.5 years!
used some lube/oil, NOT RVT!, and a different seal from McMark they are squarish
work them on with a twisting motion slowly to not crease or catch the seal.

Phil

Posted by: 914Sixer Jan 22 2021, 10:55 AM

Motor oil. On 1.7 engines there were two sizes of push rod tubes. Early heads had smaller diameter opening so watch for that. Use a 15mm or so deep socket with extension to push them in. You should hear a pop sound when they seat.

Posted by: iankarr Jan 22 2021, 10:57 AM

New viton seals...and hospital-clean bores. Some people put a thin coat of locktite 565 on the o-rings.

Posted by: pcdarks Jan 22 2021, 03:56 PM

I found this thread it says to put in Viton O Rings and use Loctite pipe sealant on them when installing.

http://www.914world.com/bbs2/index.php?showtopic=260801




get them from McMaster-Carr

Small Viton Orings: 9464K33 ($8.20 for 25)
Large Viton Orings: 9464K35 ($8.43 for 25)

Posted by: dlee6204 Jan 22 2021, 04:47 PM

For many years I replaced them with no sealant with marginal results. I now use Loctite 565 with great results.

Posted by: Mark Henry Jan 22 2021, 05:00 PM

Guys stating they use "Loctite 565", it's also called loctite pipe sealant, pipe dope, teflon pipe sealant, liquid teflon it's all the same stuff. I used to use it, works good, but I moved on to dow corning 55 a decade ago.

Posted by: Superhawk996 Jan 22 2021, 05:06 PM

There you go. Thats the stuff -- I couldn't remember the number when I posted. Also reminds me I gave mine away long ago and need a new tube for upcoming rebuilds this year. Thanks Mark!

https://www.aircraftspruce.com/catalog/pnpages/08-13684.php?gclid=EAIaIQobChMIhuLavdOw7gIVT_DACh0pkg3nEAQYASABEgK0zPD_BwE

Posted by: flat4guy Jan 22 2021, 08:57 PM

In the VW world they now have spring loaded ones that always have tension on them - I have used 2 sets and no leaks 2 years later. About $100 for 8

Posted by: Mark Henry Jan 23 2021, 10:42 AM

Maybe for a T1 but that won't work in a T4.

My biggest trick is I use a 1" flap sander and give the bores a quick once over and I also debur any sharp edges before the final cleaning and install of the tubes. I use the dow 55 Oring lube slight twist as I install. Once done be very careful installing the retaining spring and Bob's yer uncle.

Posted by: AZBanks Jan 23 2021, 12:17 PM

Does anyone have the part number for seals for a 1.8?

Posted by: yellowporky Jan 23 2021, 02:12 PM

We just rebuilt my stock 1.7 and i bought the expensive stainless pushrod tubes thinking that i did a good thing but they unfortunately were not as good as there price would dictate. We tried to make them round and were hopeful but after 1200 miles 2 tubes on the passenger side are leaking.
This stuff drives me crazy so i did some more research and came across these CSP tubes that are billet aluminum and under $300 shipped from Germany. Arrived in 2 weeks too.
For me it is a small price to pay to hopefully never look back. And i did just order a tube of the Dow 55.
Thank you for that recommendation.
Fingers crossed

Posted by: Dave_Darling Jan 23 2021, 10:10 PM

Those seem like a big waste of money to me. The stock ones are plenty good, and not that expensive.

Note that the stock tubes are spring-loaded, that's what the "curious bent wire" thing inside the rocker box is. It's a spring that pushes the outer shoulder of the tube inward toward the case centerline. You need to make sure that the parts of the wire that poke down into the tubes actually sit on the shoulders of the tube, or they'll rub on the pushrod and wear a nice notch in it.

--DD

Posted by: Mark Henry Jan 24 2021, 07:22 AM

I've used a few sets of aftermarket tubes and except in the odd case of an oversized stroker IMHO these are a waste of money.

If I only had two leakers I would just have another go at those two.

Posted by: yellowporky Jan 24 2021, 11:37 AM

If they work it is worth the money to me as time to work on the cars is difficult to come by and I would rather be driving it than working on it

Posted by: pcdarks Feb 7 2021, 02:33 PM

I bought the Viton seasl from McMaster Carr. Can someone tell me the difference between Loctite 565 and 567

Posted by: 914Sixer Feb 7 2021, 03:03 PM

My engine has been on the stand for 4 months after run in with no oil leaks. No sealant anywhere except for engine case and oi pump gasket

Posted by: Rav914 Feb 8 2021, 12:15 AM

Viton seals. I've removed the heads three times in the past few years for reasons unrelated to leaking. I replaced the seals each time, never reused them. I also make sure the bores are super clean and then put a fine coat of engine assembly lube on the seals so they don't catch or twist. Zero leaks every time.

Stock pushrod tubes as well.