Perma-cool oil thermostat O-ring

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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dstclair
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Perma-cool oil thermostat O-ring

Post by dstclair »

I have a Perma-Cool Oil Thermostat (http://www.shop.perma-cool.com/media/300013%20rev6.pdf) that appears to be seeping a tiny bit of oil. The oil accumulates on the 'end cap'. My mechanic and I suspect that there is an o-ring behind the end cap that needs to be replaced. Before making a big mess and removing the end cap, does anyone know if there is indeed a field replaceable o-ring?

I have dropped a note to Perma-Cool as well.

It would be a bit of a PITA to replace the oil thermostat, although the part is only $80.
dave
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Re: Perma-cool oil thermostat O-ring

Post by 3Dreaming »

I don't know the answer, but I have aused one on the shelf. If I remember I'll check tomorrow.
TimTaylor
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Re: Perma-cool oil thermostat O-ring

Post by TimTaylor »

3Dreaming wrote:I don't know the answer, but I have aused one on the shelf. If I remember I'll check tomorrow.
Why don't you write yourself a note so you WILL remember? Simple enough.
Retired from flying.
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Re: Perma-cool oil thermostat O-ring

Post by 3Dreaming »

TimTaylor wrote:
3Dreaming wrote:I don't know the answer, but I have aused one on the shelf. If I remember I'll check tomorrow.
Why don't you write yourself a note so you WILL remember? Simple enough.
Because I would likely forget to bring it to work with me. :oops:
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dstclair
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Re: Perma-cool oil thermostat O-ring

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If you happen to remember, could you let me know the size?
dave
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Re: Perma-cool oil thermostat O-ring

Post by 3Dreaming »

OK, I popped the end cap off, removed the o rings and measured. There are 2 o rings. Laying on a ruler the OD is 34mm, and the ID is 30mm. I recently completed a hose change on a 912 and had the spare parts still here to show the customer. The intake to cylinder o ring for the 912 is 34x2. The thermostat o ring just fits inside of the intake o ring. The intake o ring fits the groove in the thermostat cap just fine. Based on that I would say that it is a 30x2 metric o ring.
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Re: Perma-cool oil thermostat O-ring

Post by 3Dreaming »

Also my thermostat came apart easy, just a little twist on the cap and it popped right out. Don't lose the washer. You might need a clamp or something to push it back together to reinstall the snap ring after replacing the O-rings.
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dstclair
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Re: Perma-cool oil thermostat O-ring

Post by dstclair »

I received the below from Perma-Cool:
There are two. Though they can be replaced, those t-stats are pressure tested here after assembly to insure that they do not leak. The O-rings are a little tricky when replacing the caps also as they are a tight fit and can get damaged during the assembly process (or in your case, attempting to re-assemble.) We can only tell this ourselves after the pressure test.

You might be better off ordering a new one in terms of time saved and avoiding frustration if it leaks after you have gone to the trouble of trying to repair.
Do you believe the O-rings can be replaced easily based on your disassembly?
dave
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Re: Perma-cool oil thermostat O-ring

Post by 3Dreaming »

dstclair wrote:I received the below from Perma-Cool:
There are two. Though they can be replaced, those t-stats are pressure tested here after assembly to insure that they do not leak. The O-rings are a little tricky when replacing the caps also as they are a tight fit and can get damaged during the assembly process (or in your case, attempting to re-assemble.) We can only tell this ourselves after the pressure test.

You might be better off ordering a new one in terms of time saved and avoiding frustration if it leaks after you have gone to the trouble of trying to repair.
Do you believe the O-rings can be replaced easily based on your disassembly?
I put the one I disassembled back together with the old o-rings, and it went together easy. Even with new o-rings I don't think it will be a problem, just lube the o-rings before putting it back together.
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