My Octavia failed it's MOT today for both headlamps being aligned too high. I know the tester isn't allowed to touch the internal beam adjuster and I had it set on it's highest setting before I took it in (mistake). Anyway, they tried to adjust it at the headlamp and said they couldn't for whatever reason (haven't picked the car back up yet) and mentioned something about replacing the whole units.

So, my question is if I knock the low beams down with the internal adjuster and take it back for the retest will the tester just test the beam as it is presented to him? I know the tester isn't allowed to touch the internal adjuster unless the beams are too low (then he is allowed to move the adjuster to the highest setting and then check) but is this still the case for the retest?

Check if this could help :http://www.briskoda.net/forums/topic/262934-headlight-full-beam-adjustment/

The tester should test as presented, only if one or both headlamps are too low then he is permitted to adjust via the internal adjuster to the highest position only and there is a prepared advisory which the tester can tick to say that he has used the internal height adjuster.

The procedure is in the testers manual:

http://www.transportoffice.gov.uk/crt/doitonline/bl/mottestingmanualsandguides/mottestingmanualsandguides.htm

If you are absolutely sure that they are at the correct height you could tape over the internal adjuster or disconnect it.

Surely if they were at the correct height they wouldn't have failed?

The highest setting on the internal adjuster is the normal/regular position so if they are too high then the headlights need manually adjusting down using the adjusters on the back of the headlight.

I'd want this fixing anyway, if for nothing else than to ensure I aren't dazzling oncoming drivers.

It's a simple 5 minute job to adjust the dipped beam height.

Main beam is not checked if dipped beam is available, since the test is designed to ensure that the beams do not dazzle oncoming drivers (and assume that you switch to dipped when passing other cars)

Mine failed for the headlight beam aim too high. The tester sorted it there and then no charge for it either as it took him seconds to adjust