Rear Reflectors for Road Transport Lighting Act 1953

Service Bulletin 150A dated August 1954 (Home Trade Circulation Only) is giving instructions about adding 1-1/2" diameter reflectors on the rear of XK120, Mark V, Mark VII and 1936-48 saloon models, pursuant to the Act which required them on all vehicles beginning Oct '54 in the UK. SS100, SS1 and SS2 are not mentioned BTW.

Part numbers are given for reflectors and brackets.

I think I have them on my '38.

They are marked B.S.2515 G2 (heart shaped logo) LIC.2628.

The service bulletin describes prising out some small reflectors from the centers of the setscrews securing the bumper bar.
Mine has no such small reflectors.
Here are the screws I have.

They fit the square holes in the bumper. The reflector brackets fit on them too.

Am I to interpret this then, that the reference to small reflectors in the center of screws, applies to later cars, and not mine?


MK Is had the rear bumper held on by2 large countersunk screws with a straight shank about 1/4 " long
These had a hexangonal hole in the centre where a spring clip on the small reflectors pushed in These reflectors are qute small and I think repros are still available

However , the coach bolts you show would require square holes in the bumper blade , so they and Mk IV would e incompatible.

Possibly regulations in some parts at some stage set specs fr size of reflectors. Here, whatever was legal when the car was new is stil OK.

Thanks, Ed. It sounds like you are describing something remotely like this.
So the spring clip on the reflector would push into the hex.

My bumper blade does indeed have square holes, and BTW here we call them carriage bolts, which like the term coach bolt probably means they date back to the horse drawn days and wooden vehicles.

Hi Rob,

Yes, the little reflectors on the bumper bolts were a MK4 thing. I just mounted rubber cased reflectors on my bumper. See:


LUCAS actually produced a booklet SB515 LIGHTING REGULATIONS FOR MECHANICALLY PROPELLED VEHICLES which clarified all the implications of the Road Transport Lighting Act 1953, and indeed this Act was to be introduced from 1 Jan 1954 initially, but after lobbying from British Industry not able to be ready in time, was delayed until 1 Oct 1954.
THis is not a coincidence, and is the reason for (in Jaguars case) the XK140 and the Mark VIIM having many changes made to their lighting (including reflectors) relative to the superseded XK120 and Mark VII models. Apart from Reflectors, a bigger issue was the requirement for Flashing Indicators.

But my understanding is these new rules only applied to new cars made after 1 Oct 1954, and did not apply retrospectively to cars made prior. But there was indeed confusion. The SB.150A Service Bulletin is dated August 1954, and I suspect erred on side of caution, thus maybe some XK120s/Mark IVs and IVs did get added reflectors, but given their rarity in UK it would appear the issue of retrospectivity was clarified as not being required for vehicles made pre 1 Oct 1954.

Interesting debate for the Concours Rules makers - to debit or not, XK120s/Mark V/Mark IV with added reflectors, and indeed any that had flashing indicators added.


They do give a little extra security after dark when the side lights are only a number plate apart.


Yes, I’m sure that was a large part of the impetus there.
Perhaps the owner of mine thought it a good idea even if not required.
Going back a few years, some vehicles had only one tail light, my brother’s '46 Chevy pickup for instance.
I’m always surprised to see Mark V’s with various obtrusive generic turn signals tacked onto or below the bumpers, when we in the USA had them built in to the side lights and tail lights from new, and it would be an easy conversion for cars without them.