Hvac Fan...replace or repair ?
#1
01-24-2011, 06:49 PM
Hvac Fan...replace or repair ?
Recently, my fan started failing intermittently, then almost never ran at all. Thought it might be like past cars I've had and just in need of a little lube to extend the life. Well turned out to be even easier than that and probably longer life than that.
No photos...last thing I think about when in repair mode...sorry. The removal and replace procedure is in Bentley and AudiPages...just not the motor repair...really not hard, though.
Anyway, the toughest part is getting the squirrel cage(s) off, which I did to both ends with plans off getting to the bushings/bearing to clean and re-lube....brake cleaner first, then lube with spray white grease.
After removing the spring clip where cage pushes onto shaft, and inserting a staple (or whatever works) to hold locking part of plastic bushing on cage away from grove near end of shaft, I could drive the shaft out of the cage like this: >> Holding hand under the cage (between cage and motor), then driving shaft and motor out of cage with small metal (plastic?) hammer, then same with punch to get it all the way off motor shaft. THE tightest fitting fan cage I've ever driven off a shaft...but opposite: shaft off of cage...only way I could do it, but didn't hurt a thing. If you know it's the brushes, only one cage needs to come off.
Well, turned out the problem was a stuck brush and a really easy electric motor to service. Clip just pry/pops off the end of each brush tunnel...spring comes out separate...even with brush stuck in tunnel, the entire tunnel can be pried/lifted straight out (square rubber tunnel w/square metal inner brush guide). Brush was stuck in built-up "schmutz".
Removed both brushes and tunnels...lotsa brush left (105K miles) on both...cleaned em up with brake cleaner. Commutator was just barely grooved, so I just shined it up by slipping some fine emory cloth in, pressing it in place with one of the brushes and spinning the motor with it's shaft locked in my portable Bosch drill.
Tapped the cages back on with hammer and last few mm's with a proper socket, until seated. If most are like mine, the end clips are not even necessary (I put em back anyway)...super tight squirrel cage fit on shaft, which I like.
Reassembled and works like brand new again...easily starts up at minimum fan speed with engine off...minimal voltage spins it agian...WooHoo! Easy heat and no fogged winders
May not be the problem with all of em, but sure beats a $205 fan/motor replacement.
No photos...last thing I think about when in repair mode...sorry. The removal and replace procedure is in Bentley and AudiPages...just not the motor repair...really not hard, though.
Anyway, the toughest part is getting the squirrel cage(s) off, which I did to both ends with plans off getting to the bushings/bearing to clean and re-lube....brake cleaner first, then lube with spray white grease.
After removing the spring clip where cage pushes onto shaft, and inserting a staple (or whatever works) to hold locking part of plastic bushing on cage away from grove near end of shaft, I could drive the shaft out of the cage like this: >> Holding hand under the cage (between cage and motor), then driving shaft and motor out of cage with small metal (plastic?) hammer, then same with punch to get it all the way off motor shaft. THE tightest fitting fan cage I've ever driven off a shaft...but opposite: shaft off of cage...only way I could do it, but didn't hurt a thing. If you know it's the brushes, only one cage needs to come off.
Well, turned out the problem was a stuck brush and a really easy electric motor to service. Clip just pry/pops off the end of each brush tunnel...spring comes out separate...even with brush stuck in tunnel, the entire tunnel can be pried/lifted straight out (square rubber tunnel w/square metal inner brush guide). Brush was stuck in built-up "schmutz".
Removed both brushes and tunnels...lotsa brush left (105K miles) on both...cleaned em up with brake cleaner. Commutator was just barely grooved, so I just shined it up by slipping some fine emory cloth in, pressing it in place with one of the brushes and spinning the motor with it's shaft locked in my portable Bosch drill.
Tapped the cages back on with hammer and last few mm's with a proper socket, until seated. If most are like mine, the end clips are not even necessary (I put em back anyway)...super tight squirrel cage fit on shaft, which I like.
Reassembled and works like brand new again...easily starts up at minimum fan speed with engine off...minimal voltage spins it agian...WooHoo! Easy heat and no fogged winders
May not be the problem with all of em, but sure beats a $205 fan/motor replacement.
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