braking efficiency and vacuum

[ent]

i'm failing my road worthiness test due to a lack of braking efficiency. On the rear I have new shoes and wheel cylinders and the drums are fine, the new shoes will be bedded in shortly but if I do manage to pass the test I reckon I will just about s$$$$e it. The front pads are fine, the brake fluid was replaced a short while ago, the brake master cylinder was reconditioned with a Toyota kit a short while ago and the vacuum test (pumping brake pedal 4-5 times engine off and then start engine and get slight pedal drop) is fine. I am wondering is this test sufficient for seeing if the vacuum being supplied to the brakes is enough? is there any way I can (a) check the vacuum being applied to the brake system (without requiring a measuring device) and (b) is it the servo system of the brakes that requires the vacuum? and if so how can I check that the servo is working?.....is there anything else that could be causing this lack of braking efficiency? all thoughts greatly appreciated
ent
1989 2LT

[Vagrant No2]

Have you checked the load sensing valve mounted above the rear axle is not seized as this will restrict fluid to rear brakes if seized shut .

Edit : Is yours a 89 1st gen or 89 2nd gen ?

[ent]

mines actually an LJ70 landcruiser but I believe these are very similar to the hilux/hiluxsurf as 2.4LT engine can be found in both and mechanics are similar. It was built in 1988 but first registered in '89 so I suppose it's really an '88 vehicle. Do you reckon mine would have one of these valves? are these located along the brake line, one at each side? Would anyone have a picture of one in their location so I could check if i have one?

The brake readings from my first MOT test were as follows: vehicle weight 1780 kg, brake force values: FL 256, FR 281 RL 229 RR 118. I think the values are kg of force. Braking efficiency result 49.66%. The RR reading was low due to a weak brake cylinder but as I said in previous post both rear brake cylinders and shoes have been replaced, the next test gave similar front readings and the rear reading were more equally matched at around 220. The braking efficiency had climbed to 50% but a pass is 55% I'm expecting the rear readings at the next test to climb a little, due to the fact that the shoes probably had not bedded in properly for the last test (hence the reason why the RL value dropped after getting the new shoes) but I can not see the values climbing dramatically enough to give me a good braking efficiency value, like 70-80%. Are my braking force values poor/average?

[BUSHWHACKER]

Are the rear brakes adjusted correctly? Pull the hand brake on a few times without touching the brake pedal, to take up the 'slack' between the shoes and the drums.

[ent]

they should be adjusted correctly as the shoes and brake cylinders were only replaced last week....sorry Bushwacker..you have lost me with your handbrake check..exactly what do I do? do I apply the handbrake a coupe of times whilst stationary?what am I chcking for

[stormforce]

they should be adjusted correctly as the shoes and brake cylinders were only replaced last week....sorry Bushwacker..you have lost me with your handbrake check..exactly what do I do? do I apply the handbrake a coupe of times whilst stationary?what am I chcking for

if you pull the handbrake several times then it will adjust the rear brakes properly as they have a self adjuster in them but don't touch the brake pedal while pulling on the handbrake or they wont adjust properly