PSS Shaft Seal set screw problem

[Moby Burton]

I have a PSS Dripless shaft seal on a 1-1/4" shaft. I need to move the seal in order to service the shaft coupling. I removed the two set screws from one of the holes. When I attempted to remove the upper most set screw from the other hole, I found that the set screw was corroded. I suspect I was given a steel set screw. The hex wrench will not grip the inside of the set screw as the set screw is severely corroded. Any ideas on how to get the set screw out?

[SY Harmony]

Hammer in a slightly larger torx bit
Drll them out with a left hand bit

[Moby Burton]

Good ideas. I was thinking of the left hand drill bit but will try the torque wrench first.

[Mickeyrouse]

When I serviced mine I replaced the set screws with 1/4” hex head stainless cap screws. Much easier to tighten. And per Moby Burton’s suggestion note that’s the TORX bits , not a TORQUE wrench.

[Moby Burton]

Thanks for the correction. I knew what I meant :-)

I was thinking of the bolt idea as well. I don't want to go through this again.

If all else fails, I will have to drill down to the shaft. I may end up redrilling and tapping the hole again. (But hopefully not)

[Bobby Lex]

There's really not that much pressure on the fitting (limited to the "springiness" of the compressed rubber bellows), so the inner set screw should not be excessively torqued.

The set screws are a softer metal than the shaft, so the inner set screw deforms a bit when tightened. Accordingly, PSS says NOT to re-use the inner set screw.

The outer set screw not only holds the inner one in place, but it is also designed to replace the inner set screw after the inner screw has been removed. For that to happen, the outer set screw should not be torqued very much at all, otherwise it will also deform and not be able to be used as a replacement inner set screw.

PSS sells replacement set screws.

Before you start tapping and fussing with the fitting and set screws I would put in a call the the folks at PSS. I had some questions for them about a year ago concerning my PSS shaft seal. They were very approachable, informative, and helpful. They might be able to give you some useful suggestions.

Good luck!

Bob

[Moby Burton]

Hi Bobby: Thanks for the useful information. I emailed PYI. They got back to me with the following: "To remove a stripped set screw, you can use a 13/64" left-handed drill bit or an easy out to extract it.".
That will be my next step.

[Moby Burton]

Here is the final answer. The Easy Out didn't work. I drilled a hole through the center of the set screws with a 1/8" left had drill bit. The easy out didn't work. I moved up to a 5/64 drill bit and the a 7/64 drill bit. Finally a 11/64 left hand drill bit grabbed the set screw and backed it out. The same drill bit then backed out the second set screw. I was able to get both set screws out without damaging the threads in the shaft seal. A small victory.

[s/v Jedi]

Originally Posted by Moby Burton

Here is the final answer. The Easy Out didn't work. I drilled a hole through the center of the set screws with a 1/8" left had drill bit. The easy out didn't work. I moved up to a 5/64 drill bit and the a 7/64 drill bit. Finally a 11/64 left hand drill bit grabbed the set screw and backed it out. The same drill bit then backed out the second set screw. I was able to get both set screws out without damaging the threads in the shaft seal. A small victory.

Very good! How did the screws look? Rusty? And the shaft seal thread?

[SY Harmony]

Originally Posted by Moby Burton

Here is the final answer. The Easy Out didn't work. I drilled a hole through the center of the set screws with a 1/8" left had drill bit. The easy out didn't work. I moved up to a 5/64 drill bit and the a 7/64 drill bit. Finally a 11/64 left hand drill bit grabbed the set screw and backed it out. The same drill bit then backed out the second set screw. I was able to get both set screws out without damaging the threads in the shaft seal. A small victory.

Saving the threads is a HUGE victory! Congrats

[Moby Burton]

The upper screw was rusty and the lower wasn't. I believe they were both stainless. My engine compartment got dowsed with salt water several times for various reasons. After hanging out in the Eastern Caribbean for years, I found rust on most of the stainless steel on the boat.

[Cap Bill Des]

Moby- Good for you on the PSS! Glad to hear you're still taking care of Sapphire!...

[s/v Jedi]

Originally Posted by Moby Burton

The upper screw was rusty and the lower wasn't. I believe they were both stainless. My engine compartment got dowsed with salt water several times for various reasons. After hanging out in the Eastern Caribbean for years, I found rust on most of the stainless steel on the boat.

Protect the new ones with some Boeshield T9 or Lanocoat

[Mickeyrouse]

Ah, the sweet taste of success.

[phorvati]

Originally Posted by Mickeyrouse

When I serviced mine I replaced the set screws with 1/4” hex head stainless cap screws. Much easier to tighten. And per Moby Burton’s suggestion note that’s the TORX bits , not a TORQUE wrench.

Set screws need to be cupped, otherwise collar can move and could lead to signiffciant water ingress. They are also one time use because the sharp cup edge needs to bite into the shaft.
Also stainless can corrode if o-rings are damaged or signifficant vibration exists. Water can get in and if oxygen depleted, it will corrode 316 ss set screws.
They can be drilled out fairly easy as long as you have access.