Leaking push rod tubes

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Leaking push rod tubes

Postby JRGilbert » Sun Sep 03, 2017 7:44 am

I am attempting to repair the oil leaks in my engine...with limited success.
I replaced the push rod tubes with EMPI spring loaded tubes. It looked like a reasonable thing to do, but. they leak worse than the factory tubes.

It's more than a notion to get them in.
I made a wooden tool to compress the spring and had no trouble getting them in place, however, damaged 2 of the seals and had to order another seal set.
Got the silicone seals.
I very carefully replaced the seals and checked the o-rings in the sliding tubes and reinstalled the tubes. The tube washers are in place where the push rod connects to the engine.
They are fully seated and I don't believe that I damaged any seals this time. I still have a leak.

I've been fixing sports cars over 40 years.
I've rebuilt VW engines.

Is there some magic to this that I'm missing?
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Re: Leaking push rod tubes

Postby RS-60 mark » Sun Sep 03, 2017 9:58 pm

You didn't say if they are leaking in the middle, at the case, or at the head. Several tubes, or just one?

Did you buy "standard" push rod tubes or "big mouth" push rod tubes? If you bought "standard" push rod tubes, remove the valve cover and visually assure the push rods are not touching the open end of the push rod tube at any time throughout 2 revolutions of the engine. If so, then the push rods are banging on the sealed end of the tube, breaking the seal. If you have something other than a stock 1600cc engine you may need "big mouth" tubes which have a wider opening at the head end. Having said that, it also doesn't help if you install the head end against the case.

Another thing to look for is to assure the push rod tubes are straight, and not touching anything (like cool tin under the cylinders).

Otherwise, the tubes should seal drip-free unless the seats on the head and case aren't smooth, or are scratched/gouged. Or, if you have excessive pressure in the case. I can remember watching the engine actually puffing visible mists of oil from under the case side seals until I got my case pressure problems under control. Excessive case pressure will cause other leaks too, like from the case behind the crank pulley.

And, yes, installing the spring loaded tubes can be an SOB. The trick I use is to hold the spring compressed with a zip tie. Once the tube is positioned, cut the zip tie.
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Re: Leaking push rod tubes

Postby JRGilbert » Mon Sep 04, 2017 3:48 am

I have not seen the big mouth tubes except on 914.
These are straight.
Push rods are not touching.
Openings in the head and case are smooth.
Leak is at the engine, not the head.
The seals appear to be deforming and leaking at the bottom between the tube and washer.
My engine is 2175cc.
I have 1/2" breather connections from each valve cover to a collector with 2 large breather caps.
I do have the oil mist you spoke about.
Never has a leak at the crankcase pulley.

I've come to the conclusion that the EMPI spring loaded tuber are garbage. I had hoped that I could use them and not have to pull the heads.
I noticed after the tubes had been installed and run they could not be removed again without a tap from on the head end. Seems like the o-rings stick to the wall of the tube.
Once they have moved there is no problem with the slider and easy to take out.

I have thought that if the seals were glued to the tube; that might solve the problem...but I'm past tired of messing with this.

There is one other product that uses a threaded tube arrangement. Is that any better?
The best thing may be to go back to stock parts.

Thanks for your help.

Jim
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Re: Leaking push rod tubes

Postby RS-60 mark » Mon Sep 04, 2017 10:38 am

RE: "big mouth" tubes. You are looking for aluminum tubes that specify 7/8" inside diameter. The larger diameter is supposed to accommodate high lifts and ratio rockers. The push rods will hit the the "standard" aluminum tube opening.
RE: the "threaded tube arrangement". I am not the expert, but this seems like brute force masking of a different problem.
RE: deformed seals. If the seals are deformed to the point of leaking then that sounds like seating alignment problem. (Again, the push rods can inhibit seating alignment if the push rod tube diameter is too small).
RE: sealant on seals. OK, I'll admit it, I goop the hell out of the inside and outside of the seals with hi-temp RTV. Nobody will say that is a good idea, but . . . .

You have plenty of engine case "breathing", certainly as much or more than I have. I'm at 2332, so I should see more stroke induced case pressure than 2175 and my "breathing" seems to be adequate.

One quirk I discovered along the road of trying to stop oil leaks is not to fill to the "full line" on the dipstick. I NEVER fill above 1/2 quart low. If I do, the engine will manage to eventually spit its way back down to 1/2 quart low where it likes to live relatively leak free. Don't ask my why, but fill it full = mess on the garage floor; fill it 1/2 low = happy trails.
(I do have additional thin line sump, remote filter, and external 96 plate cooling radiator. So there is much more oil in the system than the 1/2 quart low shown on the dipstick.)

Disclaimer: Even at the engine's current happy state, it is not absolutely, completely, totally drip-free. But my springer push rod tubes are dry at both ends and the center.
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Re: Leaking push rod tubes

Postby JRGilbert » Mon Sep 04, 2017 12:03 pm

The EMPI tubes are 7/8 I.D.
No push rod binding.
None of the tubes are perpendicular to the head. All have a slight angle to each other.
Ahh...the glue!
I have a remote cooler too.
This car was preped for the Panamericana 10 years ago.
I just hate the leaks.
I'll try one more time and RTV the seals.
Was interesting to read that you used RTV on the outside of the seals.
That does not appear to be a problem here.

Thanks for your help.

Jim
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Re: Leaking push rod tubes

Postby Larry Jowdy » Mon Sep 04, 2017 12:55 pm

In regard to using RTV, an engine builder who on occasion posts here used a 1/3 of tube of RTV on each end of the push rods. Another thing I've learned is to make sure the tubes are orientated correctly in other words, think of what happens to the oil when it's pumped to the valve train. It runs 'down hill' to the crank case. Look at the spring loaded tubes and you'll see that one tube slides inside the other tube. Regardless of what the instructions may say, you want the lesser diameter tube facing the cylinder head. If not, oil will pool at the location where the tubes intersect inside the larger tube.
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Re: Leaking push rod tubes

Postby JRGilbert » Mon Sep 04, 2017 2:53 pm

Wow, he must be buying really small tubes.
I'm going to give it a try...one time, before going back to stock tubes.
They need to be installed with a zipper.
Thanks for the note. I have them in correctly.
I'll report back tomorrow.
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Re: Leaking push rod tubes

Postby DannyP » Wed Sep 13, 2017 3:00 pm

I bought the Jay-Cee Guaranteed No-Leak Pushrod tubes. Heavy springs, I used a wooden tool as well.

I installed the silicon seals dry. One of them has a tiny drip that I can live with. I think I cut one a tiny bit. I'll attend to it over the winter. The tubes themselves DO NOT LEAK, and in my opinion are worth the money. Do yourself a favor and order extra seals.
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Re: Leaking push rod tubes

Postby DannyP » Wed Sep 13, 2017 3:09 pm

Also, I have a 2165 with a Webcam 86b and 1.5:1 Pauter roller rockers, steel pushrods, and has .575 lift at the valve. Jake supplied the engine with stock pushrod tubes, and there was plenty of clearance in the tubes. So I am not in agreement that bigger diameter tubes are necessary.
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Re: Leaking push rod tubes

Postby RS-60 mark » Wed Sep 13, 2017 9:53 pm

Hi Danny,
I was referring to "standard" aluminum spring loaded tubes vs. "big mouth" aluminum spring loaded tubes. The "stock" one piece bellows style tube that you are referring to probably has the biggest ID of all since it has the thinnest wall thickness.
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Re: Leaking push rod tubes

Postby JRGilbert » Wed Oct 25, 2017 6:39 am

I finally have ALL of the oil leaks stopped.
The EMPI spring loaded tubes were the problem.
The springs were over riding the tubes because they are round on each end.
They need a flat ground on both ends, like valve springs, to stop the over riding.

Thank you Larry Jowdy! I put a smear on RTV onthe seals. I also glued the seals to the tubes with the RTV.
I have driven several hundred miles since with no leaks.

I also had installed the PORSCHE valve covers made by Travis Langham. They're beautiful, but also leaked.
The screws Travis provided are threaded all the way to the button head.
They really need to have an unthreaded section about 1/4" long at the head for the o-ring to seal.
I used the RTV there and have the leak down to a stain.
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Re: Leaking push rod tubes

Postby SeductionMotorsports » Wed Oct 25, 2017 7:57 am

DannyP wrote:I bought the Jay-Cee Guaranteed No-Leak Pushrod tubes. Heavy springs, I used a wooden tool as well.

I installed the silicon seals dry. One of them has a tiny drip that I can live with. I think I cut one a tiny bit. I'll attend to it over the winter. The tubes themselves DO NOT LEAK, and in my opinion are worth the money. Do yourself a favor and order extra seals.


You want to use these. The Jay-Cee ones rarely every fail. They always seal up when swapping out leaky ones. They're more expensive but if you value your time... you'll just get these.
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Re: Leaking push rod tubes

Postby SeductionMotorsports » Wed Oct 25, 2017 8:02 am

JRGilbert wrote:I finally have ALL of the oil leaks stopped.
I also had installed the PORSCHE valve covers made by Travis Langham. They're beautiful, but also leaked.
The screws Travis provided are threaded all the way to the button head.
They really need to have an unthreaded section about 1/4" long at the head for the o-ring to seal.
I used the RTV there and have the leak down to a stain.


We carry the Type 547 valve covers, however ours don't leak. The faces are machined and the correct hardware is provided. We run them on all our turnkey engines without any leaks. If you want to upgrade, send me an email: sales@seductionmotorsports.com

Our valve covers are: $242 shipped in the US and $295 shipped internationally. It won't let me attach a picture since the file it too large, so email me if you need a picture. Thank you.

To purchase, click the links:

Purchase in the USA: http://www.paypal.me/SeductionMotorsports/242

International purchase: http://www.paypal.me/SeductionMotorsports/295

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