Broken Lifter c85

[swoeric]

C85 had oil temps go way up while flying

couldnt find anything as far as culprets externally

pulled valve springs ... valves all checked out

upon re assembly one of the pushrod on one cyl wouldnt go all the way back in..

no movement while turning the crank

looked down the pushrod tube and the lifter seem to have come apart

something is blocking the path.. has anybody come across this

[PA1195]

Re: Broken Lifter c85

How about removing the pushrod tube and pushrod. Then with a hooked wire remove the pushrod socket and then the hydraulic lifter from the lifter body? Turn the crank and the lifter body should move with the cam lobe if pressed against the lobe.

Gary

[mike lutz]

Re: Broken Lifter c85

I had a A-65 that this happened to me once. I pulled the push rod out and the push rod cap that sits on top of the lifter came with the pushrod and caught on the pushrod tube housing on the side of the case. In rotating the engine it caught the little alum. housing and sprung it outwards. Had to loosen the cylinder and replace the housing. Since then I always make sure the caps are all in place before installing the pushrods.This happened years ago and since then I have caught this once or twice over the years on different engines after having the cylinders off.

[3Dreaming]

Re: Broken Lifter c85

I had a customer who with a old 172 With a 0-300 who was doing a favor for an Ag pilot operating out of his airport. The were flying to another airport to pick up some parts. About 15 miles out the engine went to running rough. The rocker bosses separated on one of the cylinders. The Ag pilot being a nice and a mechanic bought him a new cylinder and helped change it out. One of the pushrod socket came out and got crossways preventing the pushrod from going in all the way. After a little hammering trying to get it back together he broke the cam follower.

The rest of the story is, I had to go remove the engine, split the case, and replace the broken cam follower. It also got 5 more new cylinders. Who ever had done the overhaul a few years before this happened had not complied with the AD on the rocker bosses, an 4 out of the remaining 5 cylinders had rocker shafts that were to loose.

Also as Mike said it is possible to break the housing where the lower pushrod seals are.

[Garry Crookham]

Re: Broken Lifter c85

I'm attaching a page from the parts manual showing the cam, lifter asm and pushrod. A common problem is item 3, the socket, pulls out when the pushrod is removed and turns a bit blocking the pushrod from going back in. Item 4, the snap ring isn't present on most assemblies.

[swoeric]

Re: Broken Lifter c85

I'm attaching a page from the parts manual showing the cam, lifter asm and pushrod. A common problem is item 3, the socket, pulls out when the pushrod is removed and turns a bit blocking the pushrod from going back in. Item 4, the snap ring isn't present on most assemblies.

This looks exactly like what happened... I'm guessing I still have to pull the cylinder to rectify it?

[Garry Crookham]

Re: Broken Lifter c85

Yes, probably going to need to pull the cylinder. Someone in an earlier post suggested removing the pushrod tube. The pushrod tube is pressed into the head and when removed you need the special tool to flare the pushrod in the head after reinstalling it or it will be loose and leak oil. Attached is a picture of a cylinder and the tool.

[3Dreaming]

Re: Broken Lifter c85

If it is just the socket out of place, I have gotten the sockets back into place working through the pushrod tube. I used a piece of music wire and a piece of 1/8" square carbon tube that I had laying around.

[PA1195]

Re: Broken Lifter c85

Got to find someone born back in the last Century to find that pushrod tube tool. Lots of them around here. Now there's a replacement tube kit: https://realgaskets.com/product/pushrod-tube-seal-kit/

Gary

[Garry Crookham]

Re: Broken Lifter c85

Got to find someone born back in the last Century to find that pushrod tube tool. Lots of them around here. Now there's a replacement tube kit: https://realgaskets.com/product/pushrod-tube-seal-kit/

Gary

Not sure just how to take that comment! My tube flaring tool is probably 40 years old and one of the tool supply companies had them for sale at Oshkosh last year for around $80. The Real Gasket replacement kit and tool will cost almost $500 to do all 4 cylinders plus labor.

[PA1195]

Re: Broken Lifter c85

Not sure just how to take that comment! My tube flaring tool is probably 40 years old and one of the tool supply companies had them for sale at Oshkosh last year for around $80. The Real Gasket replacement kit and tool will cost almost $500 to do all 4 cylinders plus labor.

Hah! Take it however suits you as it's meant well. The tool would pay for itself in one job at our Alaska labor rates of $115-25/hour: https://www.aircraft-tool.com/shop/detail.aspx?id=4915A New mechanics without experience might prefer to draw labor and remove and reinstall everything to earn a day's wages on one job.

The advantage of the Real Gasket Kit is for owners with one or two problem tubes that don't own the tool and/or not wanting to remove a cylinder and all the attending seals and attached parts.

I've used the tool but don't own one. The problem can start when someone grabs the cylinder by the two tubes and loosens them via handling.

Gary

[mike lutz]

Re: Broken Lifter c85

The tool should be set to the proper depth so the balls are in the original groove. Just a simple allen wench adjustment moving the collar. Turn the end screw by hand while holding the arbor with the other hand till you cant turn it by hand anymore. Then holding the arbor with a wench, take another small wench and turn the center screw around 3/4 turn and holding both wenches, turn the arbor tool one revolution and back one. Remove the tool and it should be sealed. Do not go to much or you will cut the tube off or crack it inside the cylinder. Don't ask me how I know about that. LOL. It is a simple and quick job with the tool.

[PA1195]

Re: Broken Lifter c85

Very good instructions for us that aren't experienced. I saw my mechanic cut or split the tube once (he didn't let me near) . Apparently the tool had been applied before and work hardened the tube's end. Not having another tube out came the oil resistant RTV for a temp patch until parts were coming. On one C90 I had overhauled the tech ran each end lightly after mounting on the crankcase just to make sure they were tight. Never leaked after.

Gary

[3Dreaming]

Re: Broken Lifter c85

Just to be clear the socket coming out of place was due to the pushrod removal during your investigation. It would not have had anything to do with your original high oil temp problem. If you haven't checked yet I would look at your oil screen or filter.