Service brake efficiency 46%

Hi guys, failed me mot 3 weeks ago and neck working through the to do list and I'm down to the last few things.
The info it says on the red sheet of paper is.

Brakes failure: rbt service brake efficiency :46%

Service brake below requirements.

Is this just a case of the handbrake not working very well? Maybe adjust the cable as currently it goes up to the lady click on the handle? Or donething more serious? Maybe bleed the brakes all round?

Atb

Mike

May be able to get away with adjusting it up.
Else ya gonna have to strip it down and sort it all out, they are fairly easy to work on, I find the bit that engages the hand brake seizes up.

To adjust there is a square ended 'nut' turn it 90 deg...er....I am on about probably an older version of a landy transmission style hand brake...Ignore me.

Which disco you got?

its got nothing to do with the hand brake but if its a disco 1 then its not uncommon for the rear brakes to be poor make suer the calliper pistons are not sezed and the disks and pads are ok
but to get a mesurement of 46% then they have put your disco on a rooling road this is a big no no they should not put a land rover on a rooling road

300tdi Disco

Ok, So is it the handbrake or not?

I have adjusted the bolt and the handbrake is now fully on after 2 clicks which I am happy with.

With regards to the rear caliper, when I strip it down tomorrow should I have replacement calipers at the ready or see what I find?

martinhollings said:

its got nothing to do with the hand brake but if its a disco 1 then its not uncommon for the rear brakes to be poor make suer the calliper pistons are not sezed and the disks and pads are ok
but to get a mesurement of 46% then they have put your disco on a rooling road this is a big no no they should not put a land rover on a rooling road

Click to expand...

It is perfectly ok to put a Disco on a rolling road to test the brakes, so long as:

1. The vehicle does not have it's centre difflock locked &

2. the rollers on the rolling road contra-rotate

Thought you weren't supposed to pull the handbreak on whilst it's moving anyway? Damage to transmission/drive train?

martinhollings said:

its got nothing to do with the hand brake but if its a disco 1 then its not uncommon for the rear brakes to be poor make suer the calliper pistons are not sezed and the disks and pads are ok
but to get a mesurement of 46% then they have put your disco on a rooling road this is a big no no they should not put a land rover on a rooling road

Click to expand...

Er am I incorrect to say that a transmission hand brake is operated on the propshaft and has fek all to do with the rear calipers?

MikeDISCO said:

300tdi Disco

Ok, So is it the handbrake or not?

I have adjusted the bolt and the handbrake is now fully on after 2 clicks which I am happy with.

With regards to the rear caliper, when I strip it down tomorrow should I have replacement calipers at the ready or see what I find?

Click to expand...

So is it just your handbrake that you need to do here?
If so the rear calipers are irrelevant. Please correct me if I am wrong.

Service brake efficiency is referring to your foot brake - Park brake efficiency would be referring to your handbrake !

So, My plan of attack should be...

1, Bleed the brakes
2, check condition of caliper and pistons
3, replace calipers

???

Evans Garage said:

Service brake efficiency is referring to your foot brake - Park brake efficiency would be referring to your handbrake !

Click to expand...

Ah I see
Thank you

I got confused:lol:

Jacked it up and removed wheel, got my mate to operate the brake as I watched to see what was happening.

The Disc was moving as the calipers clamped onto it???

I undid the 5 bolts and removed drive flange thingy, remove first nut and tab washer to find that the 2nd nut was loose?? god knows how I have never touched it.

Anyway, Tightened it up like a good en, put it all back together.

I then replaced all the UJ's and the rubber donut, so on the way home will see if all my hard work has paid off lol.

Thanks for all the comments.

Mike

how tight did you tighten it ,it should only be nipped enough to remove freeplay thats why theres 2 nuts and tab washer to lock both together ,if you really did over tighten it wheel brg will fail big style

MikeDISCO said:

Jacked it up and removed wheel, got my mate to operate the brake as I watched to see what was happening.

The Disc was moving as the calipers clamped onto it???

I undid the 5 bolts and removed drive flange thingy, remove first nut and tab washer to find that the 2nd nut was loose?? god knows how I have never touched it.

Anyway, Tightened it up like a good en, put it all back together.

I then replaced all the UJ's and the rubber donut, so on the way home will see if all my hard work has paid off lol.

Thanks for all the comments.

Mike

Click to expand...

:doh:

Take it all apart again and set the pre-load on your wheel bearing FFS.
Do a search there are plenty how to's.....

Yep, sounds like a haynes manual is needed!

Service brake efficiency low: could need a bleed but IME most likely seized pistons. Push all pistons out and give them a clean where possible. Ideally remove pistons but be careful with seals or plan to replace them. Disco brakes can be very good when the pistons are nice and clean, and more importantly are all working!

Need to service all 4 calipers, then bleed the system.

Check all your wheel bearings whilst you are there. Simple rule of thumb is to tighten first nut hand tight whilst spinning the disc, place washer on, then tighten second nut bastard tight and lock washer down. Not 'by the book' but works for me

Please make sure you are competent before attempting these repairs!

Cheers

2 clicks on your handbrake will be to tight and you may notice a clunking from the gearbox as you come on and off the throttle gets worse as handbrake drums gets hotter as the shoes are dragging.
The old two clicks for mot went out of the window years ago so lang as here is reserve travel all is okay.


Lynall

2 new callipers new discs and pads £130 plus vat padock motors
opps caps on