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-   -   Cooling fan motor repair (https://www.the75andztclub.co.uk/forum/showthread.php?t=315231)

chicochapman 12th September 2021 14:49

Cooling fan motor repair
 
I see on the Rave disc there is this dire warning :-


"Caution - fan assembly must be replaced if removed, do not fit original assembly"


Anybody know what the risk of putting back the old unit might be?
thanks,
Malc
PS this looks like quite a big job, just to get at the motor :eek:

vitesse 12th September 2021 18:49

I believe the statement refers to the fan blades rather than the motor. The plastic bayonet clips holding the blades to the motor spindle are said to get brittle with age, however Iíve re-used the fan blades on several occasions and never bought new blades.

Regards

chicochapman 13th September 2021 19:21

Thanks for the re-assurance. I'll just be careful.
Malc

chicochapman 14th September 2021 19:36

Now can you remember what size socket you used to "hold" the centre spindle nut with ?
I've got a 1/4" drive socket set that stops at 14mm which seems too small
but might have been thin enough and a 3/8" drive set where the wall is too thick. Looks like a 15mm size ?
thanks,
Malc

Arctic 14th September 2021 20:22

Quote:

Quote:

Originally Posted by chicochapman (Post 2899578)
Now can you remember what size socket you used to "hold" the centre spindle nut with ?
I've got a 1/4" drive socket set that stops at 14mm which seems too small
but might have been thin enough and a 3/8" drive set where the wall is too thick. Looks like a 15mm size ?
thanks,
Malc


Hi Malcolm.
To remove the fan blade you do indeed need a thin walled 15mm socket, which will hold the nut while you turn the blade clockwise.

If you are referring to repairing the fan motor with new brushes, then the fan as whole including the cowling needs to be removed from the car, takes about an hour.

Bumper off, slam panel off with lights attached, then remove the fan, if your car as gas then it's best to cut the cowling round the A/C joints so you do not have to disturb the A/C gas.

If the motor is ok and the brush board is ok you can add new brushes, then fit the fan back on the car.

https://youtu.be/v422cKkvFAk


https://youtu.be/ls1BJGxUoPo

vitesse 14th September 2021 20:52

Just a slight revision to the above, even though Arctic is vastly experienced. I suggest you don't cut the cowling or attempt to remove it, instead when everything is unbolted / free, raise and pivot the right hand side (as you face it) outwards. There's enough room to get your hand in between and undo the three torx bolts holding the fan motor. Done about 10 fan jobs this way and will be helping another owner next week.

Try and time the job so that you can drench the torx bolts, and ideally the two cowling waist bolts while you have lunch, they can be quite stubborn.

Good luck

ps. When he says takes about an hour, that means 2 and a half hours for us mortals

chicochapman 14th September 2021 22:25

Gentlemen - thank you very much for your guidance.
Without this forum I'd have no chance of keeping this car on the road.
thanks,
Malc

chicochapman 16th September 2021 19:15

........and finally
 
here it is
https://www.the75andztclub.co.uk/for...38aa09bed0.jpgand I think I can see what's caused the fan to stop working!

Even with all the help I've had it was still a difficult job due largely to the number of seized fasteners. Some of them I've resorted to grinding the heads off and because of this while I could see that Vitesses' technique of swing the shroud out to access the three set screws holding the motor would work, I went with Arctic's suggestion of butchering the shroud to clear the A/c pipework. Even then, I had to grind one fastener off. I think in the earlier part of its life, this car has spent some time at the sea-side.


For anyone like me, tackling this job for the first(and hopefully last) time, here are a couple of tips
At the bottom of the shroud(or cowl) are two small metal clips holding it onto the radiator(easy to miss)
In terms of taking the "lid" off the motor, Arctic makes it look easy but my mole grips were too clumsy for that so I used a flat faced punch to straighten up the small tangs and then holding the motor in one hand I tapped the three lugs in turn with a medium hammer and slowly the lid came off.
Of course, my only experience of replacing brushes was on my 1968 Midget so foolishly I was expecting expecting screw in lugs on the brushes but now I see its soldering time. Good job I've got a solder sucker.
So, just got to put it all back together now.
Malc

stocktake 16th September 2021 19:33

The first time it is without doubt daunting, there are a few of us on here that have done quite a few now and you still worry if the two torx on the front panel will come off ( there is a work around if they don't) and then if the three motor body torx will come out and then what is the state of the board in the motor and the rest and finally and hopefully the magnets aren't cracked.
Still when you plug it in (laid on the floor before you put it all back together I may add ;) ) it's a great feeling when it spins into action.

vitesse 16th September 2021 21:45

Quote:

Originally Posted by chicochapman (Post 2899847)
here it is
https://www.the75andztclub.co.uk/for...38aa09bed0.jpgand I think I can see what's caused the fan to stop working!

Even with all the help I've had it was still a difficult job due largely to the number of seized fasteners. Some of them I've resorted to grinding the heads off and because of this while I could see that Vitesses' technique of swing the shroud out to access the three set screws holding the motor would work, I went with Arctic's suggestion of butchering the shroud to clear the A/c pipework. Even then, I had to grind one fastener off. I think in the earlier part of its life, this car has spent some time at the sea-side.


For anyone like me, tackling this job for the first(and hopefully last) time, here are a couple of tips
At the bottom of the shroud(or cowl) are two small metal clips holding it onto the radiator(easy to miss)
In terms of taking the "lid" off the motor, Arctic makes it look easy but my mole grips were too clumsy for that so I used a flat faced punch to straighten up the small tangs and then holding the motor in one hand I tapped the three lugs in turn with a medium hammer and slowly the lid came off.
Of course, my only experience of replacing brushes was on my 1968 Midget so foolishly I was expecting expecting screw in lugs on the brushes but now I see its soldering time. Good job I've got a solder sucker.
So, just got to put it all back together now.
Malc

Can't really see how much is left on those brushes, most of the motors I've worked on have had a none existent brush or just a sliver, sometimes even worn so much that the spring has eaten into the commutator.

Doing another one on Tuesday at 10am, bloke faces a 3hr drive to get here but local garage rates are about £160 per hour, so we help each other if we can and I don't mind some quality garage time.

Good luck with the rest of the job

ps Forgot to ask how long it took, please don't say an hour as suggested by Arctic, as I never manage anywhere near his time.

vitesse 16th September 2021 21:51

Quote:

Originally Posted by stocktake (Post 2899851)
The first time it is without doubt daunting, there are a few of us on here that have done quite a few now and you still worry if the two torx on the front panel will come off ( there is a work around if they don't) and then if the three motor body torx will come out and then what is the state of the board in the motor and the rest and finally and hopefully the magnets aren't cracked.
Still when you plug it in (laid on the floor before you put it all back together I may add ;) ) it's a great feeling when it spins into action.

OK Old wise one, what's this work around for the two torx on the front panel? Those have slowed me down more than anything else, brand-new bits = no chance, angle grinder to cut a proper slot = sometimes, welding a metal bar = usually, grinding and drilling them out = always.

Please share part of the secret of your record breaking time ...

Mike

Arctic 17th September 2021 00:32

[QUOTE]
Quote:

Originally Posted by stocktake (Post 2899851)
The first time it is without doubt daunting, there are a few of us on here that have done quite a few now and you still worry if the two torx on the front panel will come off ( there is a work around if they don't) and then if the three motor body torx will come out and then what is the state of the board in the motor and the rest and finally and hopefully the magnets aren't cracked.
Still when you plug it in (laid on the floor before you put it all back together I may add ;) ) it's a great feeling when it spins into action.[/QUOTE

]

Hi Mike.
Dave will know for sure as we did a fan together a few meets ago now, time was i think from removing the bumper, slam panel, fan, refitting another and put it all back together around 2 hrs so removing the fan is easy to do in an hour. ;)


https://i.imgur.com/y3DBlSml.jpg1

https://i.imgur.com/4UJpEFEl.jpg2

Bumper removed as above now the slam panel with lights attached, take note of those two torx that are a nightmare.
https://i.imgur.com/OL2e1qml.jpg3

I doubt these would ever more unless you drilled then out.
https://i.imgur.com/Db0Na92l.jpg4

https://i.imgur.com/1sXq39yl.jpg5

Slam panel off take note where the two torx where holding the slam panel to the rubber grommets.
https://i.imgur.com/Gxt5J5Ml.jpg6

Nibble around the A/C joints.
https://i.imgur.com/yxHCGTDl.jpg7

https://i.imgur.com/kOLXaNEl.jpg8

lifting the cowling from the radiator.
https://i.imgur.com/mjBnXFHl.jpg9

https://i.imgur.com/hAV2rn5l.jpg10

Fan is off the car, ready to be changed or to remove the lid off the motor and replace the brushes.
https://i.imgur.com/dKiKOlQl.jpg11

New fan fitted after messing around with the old fan for 20 minutes or more.
https://i.imgur.com/vYqrengl.jpg12

There was a lot of spurious wiring on the slam panel & on this car, before it could be put back together.
https://i.imgur.com/RSXXstCl.jpg13

https://i.imgur.com/gXfUktLl.jpg14

The lights had been tampered with.
https://i.imgur.com/cD8hWqal.jpg15

https://i.imgur.com/EbW5Vj0l.jpg16

So this took longer than usual :}
https://i.imgur.com/nu5qQaHl.jpg17

If the wiring had needed to be sorted out then front would have been back on by 11.10am at the latest.

This is what the fan motor looked like, you can already tell its been burnt out.
https://i.imgur.com/QOnjI5Ql.jpg18

https://i.imgur.com/nN9CChrl.jpg19

https://i.imgur.com/wEf7XOHl.jpg20

The motor is burned
https://i.imgur.com/3QRumRvl.jpg21

Wiring burnt through.
https://i.imgur.com/SlCTKb8l.jpg22

Coils burned.
https://i.imgur.com/jJqJRi6l.jpg23

This was only good for spare such as the wring loom, control box and PCB.
https://i.imgur.com/3TlyggQl.jpg24

https://i.imgur.com/XWC3kXDl.jpg25

I find it always best to remove the fan altogether it saves time in the long run. ;)

vitesse 17th September 2021 07:52

Thanks Steve, yes I remember Dave mentioning your record time. Best I've achieved is 3.5 hrs with an assistant. Hopefully the OP will say that it took him 2 hrs plus just to get the fan out:}

Doing another one on Tuesday, and have advised the owner that it can take about 5 hrs - always like to prepare owners with some margin and then sometimes the headlights need a polish too.

Dave mentioned he had some sort of work around for those pesky torx, will be interesting to hear his words of wisdom.

Keep well

Arctic 17th September 2021 08:57

Quote:

Originally Posted by vitesse (Post 2899914)
Thanks Steve, yes I remember Dave mentioning your record time. Best I've achieved is 3.5 hrs with an assistant. Hopefully the OP will say that it took him 2 hrs plus just to get the fan out:}

Doing another one on Tuesday, and have advised the owner that it can take about 5 hrs - always like to prepare owners with some margin and then sometimes the headlights need a polish too.

Quote:

Dave mentioned he had some sort of work around for those pesky torx, will be interesting to hear his words of wisdom.

Keep well

Hi Mike.
I have it up on the work around in the post above with the photo, you leave the torx in place and pull the slam panel off the rubber connections, leaving the plastic sections attached to the slam panel.

Then the trick is to trim down the rubber connections, add some rubber grease or vaseline to them then when you come to re-fit the slam panel it will push back on nicely ;)

vitesse 17th September 2021 09:45

Quote:

Originally Posted by Arctic (Post 2899929)
Hi Mike.
I have it up on the work around in the post above with the photo, you leave the torx in place and pull the slam panel off the rubber connections, leaving the plastic sections attached to the slam panel.

Then the trick is to trim down the rubber connections, add some rubber grease or vaseline to them then when you come to re-fit the slam panel it will push back on nicely ;)

With you now:}. I might well try it that way if the torx give me grief on Tuesday.

Thanks

chicochapman 17th September 2021 10:29

ps Forgot to ask how long it took, please don't say an hour as suggested by Arctic, as I never manage anywhere near his time.[/QUOTE]


Probably spent 6 or 7 hours on the job so far including sourcing a 15mm thin-walled socket.
Just on the soldering now!
Malc

vitesse 17th September 2021 11:29

Quote:

Originally Posted by chicochapman (Post 2899941)
ps Forgot to ask how long it took, please don't say an hour as suggested by Arctic, as I never manage anywhere near his time.


Probably spent 6 or 7 hours on the job so far including sourcing a 15mm thin-walled socket.
Just on the soldering now!
Malc[/QUOTE]

Nice to hear that I'm not the only one who can't match Arctic's work:}

genpk 17th September 2021 18:29

ive done about 3 of these fans but two of the 3 had badly worn copper commutators.
At one point i did a bit of research into alternative fan motor as the cost of the original Seimens ones were crazy expensive.
Did find that a chevy model used the exact same fan motor with the same fan attachment on the shaft but half the price.

vitesse 17th September 2021 18:44

Quote:

Originally Posted by genpk (Post 2900012)
ive done about 3 of these fans but two of the 3 had badly worn copper commutators.
At one point i did a bit of research into alternative fan motor as the cost of the original Seimens ones were crazy expensive.
Did find that a chevy model used the exact same fan motor with the same fan attachment on the shaft but half the price.

Think I remember you mentioning it quite a few years back and then I had a look at JC Whitney's website but although some looked similar I was never really sure so if you can tell us which year/model of Chevy that would help.

Surprisingly, USA parts are easier to source in Sweden than Rover ones.

Keep well

ps. I've got a Chevy S10 outside, must remember to check:}

chicochapman 17th September 2021 19:08

Just in case I have to come this way at some time in the future, I've bought a slack handful of HEX HEAD set screws for the re-assembly.


And here's today's tip - one of the torx heads I had to grind off was one connecting the slam panel to the wing. So thinking this was fairly important
I didn't want to try drilling it out and ruining the thread but there was just enough thread sticking out underneath to get locknuts on, so I was able to turn it out that way.:}

stocktake 17th September 2021 20:35

Quote:

Originally Posted by vitesse (Post 2899914)
Thanks Steve, yes I remember Dave mentioning your record time. Best I've achieved is 3.5 hrs with an assistant. Hopefully the OP will say that it took him 2 hrs plus just to get the fan out:}

Doing another one on Tuesday, and have advised the owner that it can take about 5 hrs - always like to prepare owners with some margin and then sometimes the headlights need a polish too.

Dave mentioned he had some sort of work around for those pesky torx, will be interesting to hear his words of wisdom.

Keep well

Sorry, missed this :o
Had a few where the torx will not move, when everything is undone you can pull upwards on the front panel and the brackets the torx bolts hold on will pull up and over the rubber bung and off it comes. To refit you trim the upper overhang on the rubber add a little grease and the brackets will push back over the rubber bushes. As the front panel is held on in many other places the rubber bushes are sandwiched in place and still do their job ;)

vitesse 17th September 2021 21:26

Quote:

Originally Posted by stocktake (Post 2900035)
Sorry, missed this :o
Had a few where the torx will not move, when everything is undone you can pull upwards on the front panel and the brackets the torx bolts hold on will pull up and over the rubber bung and off it comes. To refit you trim the upper overhang on the rubber add a little grease and the brackets will push back over the rubber bushes. As the front panel is held on in many other places the rubber bushes are sandwiched in place and still do their job ;)

Thanks Dave, but Steve beat you too it:}. The OP's idea of locknuts from underneath once removed seems quite clever too.

Keep well


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