Thread Number: 38913  /  Tag: 50s/60s/70s Vacuum Cleaners
Hoover U4029 Operating Temperature
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Post# 413213   8/29/2019 at 10:01 by ian1035nr (Welland, Ontario)        

Howdy, everyone

I'm looking for some information on how hot a Hoover U4029 Convertible should be running.

I picked one up off the local classifieds ads, and it was in rough shape, so I dismantled and have been working on repairing it the best I can.

Up until now, I've only ever worked with Kirby's, so I'm not too familiar with the characteristics of Hoovers.

Both motor bearings were replaced with band new ones, and the motor spins freely when turned by hand. But within a few minutes of running, the motor starts to get really hot; I can't even place my finger on the top bearing cover for any length of time.

Right now it has a brand new, genuine type C bag, and the brushroll hasn't been installed yet.

Can anyone chime in if this is normal behavior?

Post# 413218 , Reply# 1   8/29/2019 at 11:16 by bnsd60m9200 (Ponder,TX)        

bnsd60m9200's profile picture
no its not normal. it should be warm, slightly hot, but not so hot you cant touch it. if the top bearing overheats, either its not properly oiled, was greased and is ruined OR the commutator shaft is bent. the last one is least likely but does happen.

try oiling first, if that doesnt help, take the motor apart and look the see of the commutator shaft is bent. if it is, get a parts motor or machine, itll be far cheaper than a new armature.

Post# 413219 , Reply# 2   8/29/2019 at 11:17 by bnsd60m9200 (Ponder,TX)        

bnsd60m9200's profile picture
also, DO NOT run the motor without the belt and brushroll. its not designed for that and could also be the source of your problem.

Post# 413220 , Reply# 3   8/29/2019 at 12:01 by ian1035nr (Welland, Ontario)        

I hooked up a new brushroll and belt, still gets really hot. So I swapped out the bearing for another new one, still the same problem. These bearings are sealed and cannot be oiled, but when spinning them by hand, there's no resistance.

I had a brand new armature lying around, so I tossed it in there, and it's still the same.

Then I ran the numbers on the motor's casing, and found something truly bizarre; the model number is 43574191, that's a 6 amp motor belonging to a Hoover Guardsman.

Would it be normal for the 6 amp motor to run super hot compared to the original 4 amp motor, or is something still amiss?

Post# 413223 , Reply# 4   8/29/2019 at 13:04 by bnsd60m9200 (Ponder,TX)        

bnsd60m9200's profile picture
yes those upper bearings can be oiled. ignore the stupid press on warning. oil it and if its still hot get back to me.

Post# 413225 , Reply# 5   8/29/2019 at 13:17 by ian1035nr (Welland, Ontario)        

The cap is riveted in place, there's no way for me to get any oil in there.

All of these bearings are brand new, I just pulled them out of the bags, and they turn smooth as silk. Whatever the problem is, I think it's something other than the bearings. The whole armature and field magnet heat up; but the motor shows no signs of struggling when it's powered up. It's spinning fast and moving air really well.

Post# 413228 , Reply# 6   8/29/2019 at 17:06 by bnsd60m9200 (Ponder,TX)        

bnsd60m9200's profile picture
yes you can get oil in it, take the screws off, turn the top bearing upside down and put oil in the hole. there is felt to obsorb the oil. those bearings thought "new" lube has long since dried out is is no longer usable. the top bearing is babbot bearing, not ball bearing and can be oiled.

Post# 413235 , Reply# 7   8/29/2019 at 23:17 by MadMan (Chicago, IL, USA)        

madman's profile picture
Does the motor's cooling fan exist? If it doesn't have one, that could be the problem.

Also if your motor is mismatched, it may have the wrong armature in it. Or something.

Post# 413236 , Reply# 8   8/30/2019 at 02:04 by ian1035nr (Welland, Ontario)        

The cooling fan is installed, and it moves plenty of air. The armature in the Guardsman motor has a slightly different design from the older Convertible armature, it fits a narrower bottom bearing; so mixing them up is unlikely.

I'll check if there's a part number on the armature when I get home from work, and see if it's what's meant to be in there. But I'm assuming that at some point during this thing's life, someone grabbed an complete Guardsman motor and put it in there. The rest of the motor is definitely all Guardsman.

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