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Magnet oil filter- DIY style -updated

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Brucey
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Post by Brucey » Thu Jun 06, 2013 9:17 am

more magnets catching wear particles in PAS reservoir here;

viewtopic.php?p=149084#149084

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Drew
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Re: Magnet oil filter- DIY style -updated

Post by Drew » Sat Oct 20, 2018 3:58 pm

Undead alert!!!
:D
A reprise of one of Bruce's (many) greatest hits. I always meant to do this on my E24, and got some magnets from a defunct mk2 Golf starter, but then.... well not sure what happened but the magnets never got fitted, that's for sure.
So, now doing an oil service on my E9 so I looked out the magnets, yes I still have them 3 house moves later!
See photos, was thinking of fitting simply with a couple of giant jubilee clips, which might crack the magnets I guess, as the curve of the magnets are tighter than the canister, leaving an air gap.

But then again, perhaps fitting a jubilee on the canister "underneath" the magnets, to provide a "floor" for the magnets, to stop them slipping down and off. And a plastic cable tie to hold the magnets on to the canister. The canister is steel though so magnets are stuck on like limpets, it'd take a big pothole to dislodge them I think.

Thoughts?
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Brucey
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Re: Magnet oil filter- DIY style -updated

Post by Brucey » Sat Oct 20, 2018 7:30 pm

the later cars have an aluminium oil filter housing, so with those you don't have a choice; you need a band of some kind. The magnets are best held on in some way or other but may stay put OK on a steel canister without. However there are a few things to note;

- the proximity of the alternator; it might be very close (it is on later cars) and if it touches it shorts the battery out (very bad indeed)

- the field strength inside the canister; most of the flux from the magnets will happily be flowing through the canister which doesn't leave much inside the canister to hold the particles you want to trap. Test the field strength by seeing if a (unmagnetised) screwdriver sticks or not.

If there isn't enough field strength inside the canister then you have to put the magnets someplace else, fit an aluminium canister (I think the later ones won't fit they are a different size, but you will soon find out) or fit much stronger magnets. Rare earth ones are quite a bit stronger than the ferrite type that you appear to have; rare earth magnets will certainly produce enough field strength to penetrate a thinner canister such as those which are used on disposable cartridge filters. Not so sure about a thicker re-usable one.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

brickwhite
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Re: Magnet oil filter- DIY style -updated

Post by brickwhite » Sun Oct 21, 2018 4:24 am

Have you seen these that fit on top of the filter?

https://www.amazon.com/Motion-Pro-Oil-F ... ter+magnet

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Drew
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Re: Magnet oil filter- DIY style -updated

Post by Drew » Sun Oct 21, 2018 8:04 am

brickwhite wrote:
Sun Oct 21, 2018 4:24 am
Have you seen these that fit on top of the filter
Pretty nifty, have you used one?

I tried throwing some of my smallest washers in the canister, and the magnetic force holding them to the sides was very weak, so Brucey is right, again :roll:

How about some small neodymium magnets stuck on the inside of the canister? There's plenty of clearance in there. I have some somewhere, trick is to find them....

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Brucey
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Re: Magnet oil filter- DIY style -updated

Post by Brucey » Sun Oct 21, 2018 10:26 am

Drew wrote:
Sun Oct 21, 2018 8:04 am

How about some small neodymium magnets stuck on the inside of the canister? There's plenty of clearance in there. I have some somewhere, trick is to find them....
yep, that has to be the way to go if you have a steel filter housing and enough clearance; that is what works in the PAS reservoir too (link above)

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Drew
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Re: Magnet oil filter- DIY style -updated

Post by Drew » Thu Oct 25, 2018 5:48 pm

Thanks for replying Bruce
The finished result
I'm on it with the PAS too....
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Brucey
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Re: Magnet oil filter- DIY style -updated

Post by Brucey » Thu Oct 25, 2018 10:09 pm

looks good!

I wouldn't be at all surprised if you harvest quite a few particles after just a few hundred miles.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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