Rainbow d4c - was loud before but got less noisy and electrical burn smell

[ralph123]

Hi. Was using inherited rainbow d4c which seemed a little loud since we got it. While it was running, it suddenly started running quiet but has electric burning smell. Any idea what might be wrong with it?

 

[thevacomaticiec]

bearing or wires gettting hot slow it down id open it up see whats melted

 

[panasonicvac]

What does your commutator look like in the armature? That would be my first thought.

 

[dysonman1]

Bet the commutator is burned out. That's what happens when bearings are not repacked and motor runs a while.

 

[ralph123]

Hello Tom,

Assuming you are correct (based on your extensive experience and expertise), what would need to be done to fix the Rainbow? Is the motor shot? Is it even worth fixing? Thanks.

 

[evolutionclean1]

Those machines

Were SO popular, parts machines aren't in short supply! I've done multiple motor swaps and finally cobbled one together that is perfect after an overhaul. All you need to do is check out an old vacuum shop or marketplace and they'll have D4s with not so pretty bodies and solid motors, and then someone will be happy to walk you through replacing the motor. Heck, send me an email and I can walk you through it on a video call

I was very daunted the first time I took one apart, but once you've done it, it's a snap

 

[dysonman1]

Armatures and carbon brushes are still available on eBay. Like Jake said, it's not a difficult repair. There are three ball bearings (all the same part number), but only the bottom and middle bearing will likely need to be replaced. The very upper bearing by the carbons rarely needs more than packed with new high temp bearing grease.

 

[huskyvacs]

Stored too long without running, grease hardened and gummed up, motor is overheating because its being forcefully slowed down by the sticky grease. Service motor and replace with fresh grease and oil. Shocking how little vacuum collectors know about repairing vacuums and just say "replace the motor" to everything with no diagnosis or analysis of the problem at all.

 

[evolutionclean1]

Okay now

I was making a suggestion, but you go on ahead, Husky

It's shocking how quick collectors make assumptions that someone offering an option doesn't have a clue what they're talking about! Have you seen my collection? Have you seen my other posts? No? Go off then

 

[evolutionclean1]

Never mind the fact

That I spent countless hours attempting to bring the motor back to life in one of my d4s, and ended up having to SWAP THE MOTOR for a less worn out one, and spent even more time tearing it down to the armature frame so between what I have learned and what I have taught myself, I now have a nearly pristine D4 SE that runs like it just rolled out of the factory. I am the last person to show off, but it's gross when people assume.

To the OP, I certainly hope that what I posted earlier did not come off as it's not worth the time to try and get your D4 working correctly, as the motors are serviceable, but in the event that the motor cannot be saved, they are very easy to replace and parts machines are easy to track down.

 

[ralph123]

Your advice was perfectly reasonable Jake. My time is somewhat limited, and my main reason for asking was to determine how much it would take to make the Rainbow work again. I don't know how much I want to invest in this machine. My wife isn't particularly interested in her Mom's old vacuum. I find it somewhat entertaining to show my daughter the dirty water after vacuuming her room and bathroom. My Electrolux cleans similarly, but I can't show the dirt when finished. My options at the moment are either to store the vacuum for several years until I have time to mess with it, or send it off to be repaired. Rainvac gave me an estimate (based on symptoms that I reported) of $200 to $450 to fix. Probably take a few weeks before I have time to decide. Thanks for your advice.

 

[evolutionclean1]

No worries

I'm glad I was able to be of some help! I hope the other contributions help you as well