Trim cylinder rebuild - stripped threads on fluid line connection

[GTGeek88]

I rebuilt the starboard side trim cylinder on my Volvo-Penta SX outdrive. Seemed like I was ready to go and just needed to reattach the hoses and bleed the system. Note that I'm not really experienced in mechanical work, but there are tons of videos on everything these days and this seemed entirely possible. But I needed to replace the small o-rings on the hoses and I was thinking they were still in the port. The first one was and I got it out with a pick with no trouble. I went after the second one and it was not coming out. I may have been too aggressive. I tried a few times. Nothing. Then I realized it might be on the hose still (I'd but some flair caps on them, so it was not obvious). I took off the cap and it was on the hose and I replaced them and started reattaching the hoses. The top one, no problem. The bottom one would not cooperate. I may have damaged the threads, being in a bit of a hurry to finish up and just not realizing I was digging a bit aggressively. Now I'm trying to figure out if I can salvage this. I'm wondering can I use the pick that damaged the threads to cut enough of a groove to get the thread to bite and get it on in there. Or maybe a bolt of the appropriate size to maybe "re-cut" the theads. Note that I did the rebuild with the cylinder on the outdrive because the inner pin nearest the transom would not come out, so getting a decent view of the threads is challenging. So irritating that right at the very end I got careless and may have wasted my time and money, but I'm looking for any tips or tricks that might help out here. Thanks.

 

[alldodge]

Depends on how damaged the threads are, we cannot see what your seeing

Not seeing a pic being able to reshape threads, maybe the correct tap could, but it would need to start the cut exactly like it needs to. Post a Pic and maybe we can advise @Rick Stephens

 

[Davetowz]

I would assume by the question being asked you might not be familiar with thread repair. A new cylinder would probably be best option.

 

[Rick Stephens]

Depending on access a proper tap, or even better a chaser, is the right way to accomplish this. Could use a thread chaser but would require same accessibility as a tap.

Looks from pictures like removing it gives full access..... just gotta figure out threads (1/8th pipe?)

 

[GTGeek88]

Depends on how damaged the threads are, we cannot see what your seeing

Not seeing a pic being able to reshape threads, maybe the correct tap could, but it would need to start the cut exactly like it needs to. Post a Pic and maybe we can advise @Rick Stephens

Pics. Hope this helps you make an assessment. I'd certainly like to salvage the work I've done!

 

[GTGeek88]

I would assume by the question being asked you might not be familiar with thread repair. A new cylinder would probably be best option.

You're right. I'm not familiar with thread repair. Maybe it's one of the dark arts. I'm irritated that this has happened after doing all the work to rebuild the cylinder. Probably I did it to myself.

 

[GTGeek88]

Depending on access a proper tap, or even better a chaser, is the right way to accomplish this. Could use a thread chaser but would require same accessibility as a tap.

Looks from pictures like removing it gives full access..... just gotta figure out threads (1/8th pipe?)

View attachment 366358

Ok, here's the reply to you (accidentally replied to myself previously - is there a way to delete?):

I'm not seeing a lot because the cylinder is still on the outdrive. As mentioned, I couldn't get the pin closest to the transom to loosen up and let me get it removed and have better access. I've posted pics in a previous reply. Let me know if you think anything good is possible here. Thanks to all.

 

[Scott Danforth]

its an SAE inverted flare port. the port tool is specific to SAE inverted flair. the threads are most likely 3/8-24, however because of the inverted flair port, a standard tap will not work. A bottoming tap may work enough to get the threads re-started

some hydraulic shops have the inverted flair port taps.

custom port tool

J512 Tooling

Tri-Star Engineering provides both standard and custom J512 cutting tools.

www.tristareng.com

here are some thread chasers. https://bowerstool.com/jawco-34-tap-die-chasers-tube-rethreaders-for-flared-fittings/

 

[GTGeek88]

its an SAE inverted flare port. the port tool is specific to SAE inverted flair. the threads are most likely 3/8-24, however because of the inverted flair port, a standard tap will not work. A bottoming tap may work enough to get the threads re-started

some hydraulic shops have the inverted flair port taps.

custom port tool

J512 Tooling

Tri-Star Engineering provides both standard and custom J512 cutting tools.

www.tristareng.com

here are some thread chasers. https://bowerstool.com/jawco-34-tap-die-chasers-tube-rethreaders-for-flared-fittings/

Ah, interesting. Thanks. I'd love to get this to work. Did you look at the pics? To me it does not look too bad, but I'm inexperienced in this type of thing and it was hard to get good shots since the cylinder is still on the outdrive. I'm sure that if I went down this road, I'd have to get the cylinder removed. I used a penetrating spray from Toyota (happened to have it) and some pressure (after giving the spray some time), but that did not work. Seems like heat may be required. Or dynamite. Anyway, it would seem impossible to repair these threads without easy access to the port.

 

[alldodge]

its an SAE inverted flare port. the port tool is specific to SAE inverted flair. the threads are most likely 3/8-24, however because of the inverted flair port, a standard tap will not work. A bottoming tap may work enough to get the threads re-started

some hydraulic shops have the inverted flair port taps.

custom port tool

J512 Tooling

Tri-Star Engineering provides both standard and custom J512 cutting tools.

www.tristareng.com

here are some thread chasers. https://bowerstool.com/jawco-34-tap-die-chasers-tube-rethreaders-for-flared-fittings/

Agree, Scott has your answer
The top thread doesn't look to bad

 

[GTGeek88]

its an SAE inverted flare port. the port tool is specific to SAE inverted flair. the threads are most likely 3/8-24, however because of the inverted flair port, a standard tap will not work. A bottoming tap may work enough to get the threads re-started

some hydraulic shops have the inverted flair port taps.

custom port tool

J512 Tooling

Tri-Star Engineering provides both standard and custom J512 cutting tools.

www.tristareng.com

here are some thread chasers. https://bowerstool.com/jawco-34-tap-die-chasers-tube-rethreaders-for-flared-fittings/

Rick, above, mentioned a tap "or better yet a chaser." So what's the difference there? One problem I've had with some of this is that I can find the exploded parts list, but when it comes to indicating the sizes of various parts, that info is left off.

 

[Rick Stephens]

I'd be aching to try sharpening the starting thread on the hose nut and get it to start. There is not that much damage there.

 

[GTGeek88]

I'd be aching to try sharpening the starting thread on the hose nut and get it to start. There is not that much damage there.

I'm aching to make this work or else my time and effort has been largely (or completely) wasted. Advice on how to go about that process? AllDodge, above, has given me a link to some "chasers" that may work (still trying to determine the difference between a tap and chaser).

 

[Rick Stephens]

I'm aching to make this work or else my time and effort has been largely (or completely) wasted. Advice on how to go about that process? AllDodge, above, has given me a link to some "chasers" that may work (still trying to determine the difference between a tap and chaser).

A tap is for cutting new threads. A chaser is for clenaing up old threads.

 

[Rick Stephens]

Sharpening the starting threads is using a small triangular file to narrow the point on the first 1/2 or 3/4 revolution of the first thread. Get it to fit or slice into the bunged up threads a little easier. Does not take much filing to accomplish this. Have to REALLY careful not to cross thread since the sharper points will bite easily cross threaded as straight.

 

[GTGeek88]

A tap is for cutting new threads. A chaser is for clenaing up old threads.



View attachment 366419

Cutting vs. Repairing - well, that's simple enough. Thanks.

 

[KJM]

That looks fixable for sure, seems only the outer edge is a little out of shape. I'd try your idea first and try to re straighten up the starting edge. deeper in the threads look good.

 

[GTGeek88]

If you kind folks could look at my new thread ("Trim cylinder rebuild - Seized inner pin (closest to transom") about getting the inner pin removed so I can get this cylinder off the outdrive, I'd be appreciative.
Thanks for all the help here. I may have more questions on this in a few days.

 

[Davetowz]

I would suggest picking up a new one to get back on the water, then look at thread repair and spend time to get it done, no hurry, back on water already , then swap in the repaired cyl and see how it works. How we learn.

 

[GTGeek88]

I would suggest picking up a new one to get back on the water, then look at thread repair and spend time to get it done, no hurry, back on water already , then swap in the repaired cyl and see how it works. How we learn.

Yeah, I could. They seem pretty pricey though. I've got two kids in college, so I was trying to save money. Might not have achieved that goal, but I was tryin'.