Replacing Combustion Blower Fan Blades - Harman PP38+

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Kyle F.

New Member
Dec 24, 2012
1
My fan blades recently broke on my Harman PP38+, I have the replacment part, but have been unable to get the old disc off of the motor. I have removed the set-screw and have been dowsing it in WD40, but the damn thing will not budge.

Attached is a photo of the issue.

Any suggestions would be greatly appreciated. I want to avoid calling a technician in at $75/hr just to pull something off.
2012-12-24
 
Can you get a small wheel puller on there? Also, try a penetrating oil other than WD-40. WD works in most cases, but for stubborn stuff, a penetrating oil or PB Blaster works better...
 
I would start with the PB Blaster, then go with the Dremel if needed.
 
I would start with the PB Blaster, then go with the Dremel if needed.
 
I would start with the PB Blaster, then go with the Dremel if needed.
 
heating the fan hub with a torch will make it expand more than the shaft does. It should then slide off.
 
Hello

I have been doing alot of that lately with some success. If it does come off (does not work all the time) this is the way to do it.

1. Take a wire brush or even better a wire wheel on your dremel or drill/driver and get all the rust and oxidation off. This is what is holding the @#$$#!! thing on!
2. Soak it with PB Blaster and let it sit for a day or so to let it be drawn into the collar.
3. Take a hammer and tap it all around to dry and break it free.
4. Then try to pry or pull it off.

As I said it did work for me on one that was rusted on but your success depends on how old and how rusty it is! Good Luck!
 
I got a trick we use in the shop all the time don't laugh it works like a charm. Heat the thing to be removed (like say a rusted nut on a stud), and touch a candle to it. When the heat is correct it will pull wax down into the threads like solder on a plumbing joint. Remember wax smokes and burns use a little caution.
 
Just a tip - when you replace the fan wheel, put a touch of Never-Seez on the fan shaft and the set screw. I take off my combustion fan wheel about every other full cleaning and replace with a hint of Never-Seez on the shaft. Trying to avoid the issue you are saddled with!

f it works with spark plugs it will work for the pellet stove application!
 
Does heating the fan hub do any damage to the motor itself, bearings, etc..??
 
If set screw is out take a socket that is a little smaller than the hub an put it on hub and tap it w/ hammer. try to drive collar on a little once it moves it should be loose enought o pull off
 
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take a vice grip set it up to grip tight and snap it on twice, 90 degrees from each other on that collar......usually breaks the bond.....should come off if all the lubes you put on there didnt....
 
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Does heating the fan hub do any damage to the motor itself, bearings, etc..??
If you heat it quickly and don't dwell for a long time it should not damage the motor bearings. This is a technique I learned from a machinist where I used to work. If you are worried about the bearings, you might be able to get a damp paper towel wrapped around the shaft adjacent to the bearing, but it shouldn't be necessary.
 
hi
were your fan blades brittle and broke easy?
that happened to me a couple years ago but the fan came off easy. this was a p38 also.
 
Holy cow, taking the combustion motor off was a bear! Used all the tips except for the crayon one which I was very close to doing. Finally came off. Will be replacing the fan blade too as that got messed up during the extraction. Thanks for the tips everyone.
 
Nice... Did you get the blade collar off or did you have to remove the motor first ? ..
 
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