I need to replace one of the rear parking sensors and will obviously have to paint it before installing.

I am concerned that when I spray, the paint will find its way into the slit and clog up the sensor.

Can anyone think of a simple, but effective way of masking off the slit/groove all the way around?

It looks as if the outer bit is snapped onto the main assembly.
Can you just pull it apart?
Otherwise foam draught excluder usually works for me on similar jobs.

While I have not sprayed a sensor, in a close quarters area as you describe, I have used a "post it" piece of paper (or painters tape) with the sticky side in or out, cut it to the circumference of the slot, stuck it into the slot or around the item to avoid painting it, closed the open end, and proceeded to spray. My experience has been masking the tire valve when doing some touch-up on one of my wheels, and also masking chromed bolts where I wanted to spray the surrounding area.

Having just replaced one of these, I took the old one to bits to see what was there. The securing tabs snap off very easily! The gap that worries you is about an 1/8 inch deep and is sealed at the bottom with the rubber fitting that surrounds the inner core and is a tight fit in the outer ring. If paint could get into the gap, it would not get anywhere of concern. That said, when spray painting over such gaps on other jobs, I've never had much luck in getting the paint into such a thin gap! But if you remain concerned, you could cut a strip of suitable card, just over 1/8 inch wide and insert that into the gap to mask it.

I read somewhere that it is important not to have too thick a covering of paint as this can affect performance - a few v thin layers are best.

How about Dental Floss or sewing thread? I use them when I have to detail Plastic Model kits.

My rear bumper has three coats of paint and the sensors still work fine.

Damn... That's what my wife's bikinis are made out of. I instantly had dirty thoughts, then I read the rest of your post and realized you were talking about painting a backup sensor...

Some good ideas there. Many thanks

That looks like a generic sensor. (as others have already advised, the covers unclip easily on these).

The OE Jaguar sensors are a 'bayonet' design and easily dismantled for fitting and removal from the bumper. This makes painting very simple:



Note the two different designs used on our models - a right angled connector (item 1) for the two outer and a straight connector (item 2) for the two inner sensors.

Make sure any generic replacement sensor is the correct diameter and suitable length.

Graham

Excellent input, as ever, Graham. Could you please give me the part number of the straight sensor (n°2 in your diagram)?

The part numbers are listed to VIN A40264 for the Final Series.

1. Rear Parking Sensor - Outer : LJE7355BB
2. Rear Parking Sensor - Inner : LJE7355AB
3. Sensor Fixing Kit - Inboard : JLM21560
4. Sensor Fixing Kit - Outboard : JLM21562

Numbers 1 to 4 refer to the diagram in post #9.

Jaguar OE cost will be exorbitant! A used part from any body colour could easily be finished to Frost Blue. Alternatively, if one of your sensors has failed with no physical damage, the existing Fixing Kit could be re-used on an OE replacement sensor.

Graham

Many thanks for those numbers. Yes, I believe the dealer price is about Ł70, which is why I was scrabbling around on eBay trying to find one My sensor isn't physically damaged, it just doesn't click like the other 3 and I now always get the 5-second beep inside the car when I start the engine. Looking at your diagram above, the fixing kit appears to be just a load of rings and washers. It doesn't appear to fix any electronic components...

YES - that's exactly what the fixing kit is.

I'm away from home at the moment (south of you in the Loire Valley) and don't have access to usual information resources. However, the Jaguar fitting instruction PDF is on my MediaFire account which you can download using this link if you need it:

Jaguar XK Series - Reversing Aid.pdf

The PDF includes details on dismantling / assembling the sensors with some useful diagrams.

Graham

Wow, a mobile Jaguar guru I clicked the link, but only got a blank sheet... Not to worry, I haven't ordered the part yet, so there's no rush. Maybe you could PM me when you're back home? Profite bien de la France

An interesting comment Graham. My recent experience with sensors was on my wife's X Type, where the sensors, both the failed one that was original, and the new one, that was from the Jaguar dealer, were/are identical to the one shown in Frog's photo - not of a bayonet construction. I assumed the picture was of his correct replacement and thus wrongly assumed it was a sensor common to both models, but of course, the XK8 one is indeed a bayonet type as you decribed.
Sorry for adding confusion!! I'll back out of this with a 5 second Beep to indicate my fault now!!