Would you sand the disk/wheel at CAS??

[sinannasirli]

Hi,
when changing the Hall Effect sensor i noticed that the wheel/disk is quite rusted.. What would you do here?
Sanding the disk looks like a good thing to do, but would this affect the distance for magnetic sensor(i dont think it would affect much?) and also shall i pay extra attention for the corners of notches?

What do you think the correct approach would be here, plus do you advise anything else to look at (apart from changing the o-ring here)

Regards


Sinan

[sinannasirli]

Here are the pictures:

[lotusflasherman]

A bit of fine emery cloth will get the rust off and won't make any difference at all to the operation of the CAS. Then use a bit of oil to stop it rusting again.

It's a Hall Effect Sensor where the deep slots you can see in the disc are used to interrupt the magnetic flux to create a 'trigger point'. You want to avoid 'rounding the corners' of the slots as that would reduce the precision of the trigger but fine emery cloth will clean it up without changing anything, unless you rub it for hours and hours...

[Brit-Car-Nut]

I would not sand or otherwise scrape the rust off the wheel as the "other pickup" is highly magnetic and any left-over metal debris will be highly detrimental to the CAS

Both sensors require being in reasonable alignment with the clearances being close to original. Look at this post for pictures and measurements of a brand new CAS.

viewtopic.php?f=8&t=24681&p=311921&hilit=cam%2A+clearance#p311921

I would use a chemical rust remover. In the US, Evapo-Rust is great because it cleans the rust and then leaves a protective coating that inhibits future rusting.

You can also use "Metal Conditioner" like they use in a body shop to pre-treat bare panels but follow the mixing and application directions to end up with a rust inhibiting finish.

[sinannasirli]

Hi,
Thanks for all the quick responses. Luckily i still have a gallon left over from evapo-rust, which is like gold for me that i save to special projects..

I did not want to take the wheel apart, as it might disturb the clearances, hence did not plan of using evapo-rust (otherwise sensors would be soaked onto solution as as well)..

But now i think, taking the wheel off, and reattaching again, maybe the clearances will stay the same?

Second question, do I need to do anything like changing the o-ring inside? i.e. shall i take the whole thing apart or just clean and not bother with inside components not to create a bigger mess?

As they say "If aint broken do not fix it" every time i tried to fix a non broken thing, i did succeed to break something else on the way.... Which one is less problematic? taking the wheel off & chemical remover(plus a deeper restoration maybe) or leaving the wheel as is and light sanding..

Which one is the way to go?

But as the sensor is magnetic is makes sense that all sanded material might go and stick to sensor unless wheel removed anyway??



Thank you..

Sinan

[Simon_P]

"If aint broken do not fix it"

So don't fix it if it aint broke!

That is only light surface rust - no need to do anything other than wipe with an oily rag and then only if you feel you really have to. Also check the gaps in the reluctor ring and the tip of the magnetic sensor for debris. Do not take it to pieces unless you have to.

Replace only the O ring that you can see (yours is very flat) preferably with a Viton one - This and the one on the plug for the inlet camshaft are a cause of an oil leak.

Leave well enough alone!

[lotusflasherman]

I would not sand or otherwise scrape the rust off the wheel as the "other pickup" is highly magnetic and any left-over metal debris will be highly detrimental to the CAS

Rust, as red iron oxide, Fe2O3, has very low magnetic properties and is easily wiped off with an industrial wipe so using emery cloth is not a problem but if you've got a rust removing solution use it, it's so much easier!

[sinannasirli]

In order to soak into the rust removal solution, I need to take the wheel off..

Would taking the wheel off disturb the clearances? I assume only unscrew, clean and screw again?

I know thats only a surface rust but it concerns me if it would inhibit the sensor receipt somehow..

And basic instinct!! I want to rub it with sanding paper for hours and hours until its nice and clean!!! Joys and tears of restoration!!

[Simon_P]

I know thats only a surface rust but it concerns me if it would inhibit the sensor receipt somehow..

No it wouldn't inhibit the sensor - so there is no possible benefit for removing the rust which you can't even see with the cover on. Against a downside of having to buy a new one.
Here is the part number for your quick reference A100E6020H if you are lucky Lotus appear to still have some at £262 +VAT

when,as you say:

every time i tried to fix a non broken thing, i did succeed to break something else on the way.... Which one is less problematic?

There is a lesson there somewhere
The less problematic is to put it back on your car and drive it!

[sinannasirli]

,
The less problematic is to put it back on your car and drive it!

Agreed! Thank you