Suggestions on oil leak from pushrod seals

[Flying again!]

I had oil leaking from the pushrod shrouds on cylinders 3 & 5 on my O-540. I replaced them and no leaks for about 6 hours.

I have oil leaking from the o-ring seal at the head side of the cylinders, all 4 that I replaced. I made sure the area the seal fits in was clean with no grunge that could cause a bad seal.

I am wondering if it is a weak push rod tube seal spring. I thought I saw mention of a Lycoming SB that recommended using 2 springs to ensure sufficient compression.

Any thoughts or suggestions are welcome!

[131RB]

I am curious if you are pushing them in far enough. The O ring needs to be seated inside the cylinder not just against it. You sometimes have to seat them by hand prior to installing the spring keepers.
Ryan

[Flying again!]

Good point Ryan.

I pushed them in by hand until they "popped" in and the lower green seals had expanded. Couldn't push them in any further. That is why I am wondering if the springs are too weak.

[N941WR]

Did you use ECi clips? They had a bunch that cracked, allowing the tubes to leak.

[esco]

my O-320 pushrod shroud tubes leaked, not the seals.

Close inspection identified #2 tube was out of round at the case end, and was resolved by use of flaring tool; the dent on the bottom (adjacent to cooling fins) of #4 tube was not identified until I removed the tube completely.

Good luck!

[Flying again!]

Originally Posted by N941WR

Did you use ECi clips? They had a bunch that cracked, allowing the tubes to leak.

No ECI clips. I looked at them and they were not cracked. Thanks for the suggestion!

[Flying again!]

Originally Posted by esco

my O-320 pushrod shroud tubes leaked, not the seals.

Close inspection identified #2 tube was out of round at the case end, and was resolved by use of flaring tool; the dent on the bottom (adjacent to cooling fins) of #4 tube was not identified until I removed the tube completely.

Good luck!

Guess I know what I will be doing this next weekend, pulling the tubes. Still wonder if I should change the springs....

[131RB]

Shoot me a pm and I will give you my phone. I think this is an easy fix.
Ryan

[Flying again!]

Originally Posted by 131RB

Shoot me a pm and I will give you my phone. I think this is an easy fix.
Ryan

PM sent - Thanks

[Titan-Xpert]

Originally Posted by Flying again!

I had oil leaking from the pushrod shrouds on cylinders 3 & 5 on my O-540. I replaced them and no leaks for about 6 hours.

I have oil leaking from the o-ring seal at the head side of the cylinders, all 4 that I replaced. I made sure the area the seal fits in was clean with no grunge that could cause a bad seal.

I am wondering if it is a weak push rod tube seal spring. I thought I saw mention of a Lycoming SB that recommended using 2 springs to ensure sufficient compression.

Any thoughts or suggestions are welcome!

Some times a washer is installed under the spring clip; it tends to reduce the spring pressure. If you have these washers installed remove them. Inspect the spring clip it should not be flat. Inspect the area that the O-ring sets in the head for scratches, gouges. Polish if necessary with fine scotch brite pad. Inspect area of pushrod tube where the O-ring sets, some times this area is painted the paint can chip crack or peel. Paint should be removed from the o-ring groove and polished with fine scotch brite. When installing new seals they should be lubricated before installation, I prefer isopropyl alcohol.
On the older style narrow deck Lycoming pushrod tubes, they required two flat steel springs about .020? thick with a single washer under the springs .The newer style uses a single stamped spring about .030 to.035?thick, it is not flat, it has a lip on each end. It should not have a washer under it.
I hope this helps with your problem.