Handbrake Woes

[Doily]

My handbrake has failed MoT. But when I do the DiY check it seems OK (jack up rear wheels, 3 clicks on handbrake, can't turn wheels by hand).
So what could be wrong please? Are there any other DiY tests before I give up and pay for the garage to fix it.
Visually the bake drums and shoes are OK (I service them every year) and the footbrake efficiency is a pass.
TY for your help.

[VeiRoN]

You need to ask the MOT tester what it failed on,it might just not have enough efficiency on the rollers.

[Doily]

Sorry, I should have said : The brake was 45% efficient on the rollers.

[VeiRoN]

Handbrake minimum efficiency pass is 16%? Not sure what that 45% is about.

What is the reason for the fail on the MOT paperwork please?

[Doily]

Quote from MoT Refusal Certificate :

"Service brake efficiency is 45%, limit is 50% [1.2.1 (c)]

Thank you for your interest, much appreciated.

[VeiRoN]

That's all the brakes not the handbrake though, first thing I would do is check the condition of the front brakes.
Have a look at the brake fluid colour as well.

[MartinObviously]

Quote from MoT Refusal Certificate :

"Service brake efficiency is 45%, limit is 50% [1.2.1 (c)]

Thank you for your interest, much appreciated.

As pointed out that's the foot brake, I presume the front brakes passed.

Make sure you don't have really wide tyres that are under inflated.

A wheel lock on the rollers is a pass regardless of efficiency, so a small hard tyre will pass.

Very odd that it must have passed on the handbrake and not the service brake. that's rare. perhaps just needing a bleed or the hoses have collapsed and restricting the fluid flow.