NCT Failure - need opinions\advice

Armadillo

Well, I put the 1999 mazda 323 through and it failed on:
Parking - Brake

See printout and pics attached.

So yesterday, I had a look and couldn't see anything too much out of the ordinary. I've seen brake shoes in worse condition.
I jacked up the rear of the car (both sides supported on axel stands)
I gradually engaged the handbrake (one click at a time) and rotated the the wheels manually by hand - each in turn. On about the 6th click, they locked up.
I gave disks and shoes a good cleaning with some Lucas Brake disk and pad cleaner - there was some dust - but not excessive.
I adjusted the handbrake lever so that the wheels lock at 4 clicks instead of 6.
On driving now, the braking seems more definitive and bitier (if that's a word?)

My question:

Will I take a chance and put it through a retest?
OR
Replace the shoes and\or handbrake cable?

Armadillo

What I find odd is:

Brake Test
________________Nearside____Offside
Rear Axle________1.55 kN_____1.31 kN_____(Slight Difference)
Parking Brake_____1.81 kN_____0.59 kN____(Major Difference)___FAIL

Brake Performance
Braking Effort 78%
Parking 21%

I think 'Rear Axle' result is brake caliper and 'Parking Brake' is cable.

Is it possible to give a definite reason for these results. Nail it down and say "yep, that's the problem. Fix A, B and C and it will pass".

SouperComputer

Its most likely the cable system rather than an issue with one of the drum systems. The shoes have lots of lining left and dont show any contamination. As you rightly point out, any shoe/drum issues would appear on the footbrake test.

Either adjust or replace the handbrake cable(s). At least check the routing of the cables and ensure that there are no kinks or damage to the outer cable.

When you have done the corrective work needed, a somewhat crude test that can be done (in a SAFE environment!). Lock the rear wheels briefly with the handbrake and observe if one wheel locks considerably sooner than the other. Im talking a slight lockup here, not a tyresmoker! If the wheels are WAY off (like now) you should be able to find the imbalance without locking the wheels if you apple a decent amount of handbrake force.

Once they lock at near enough the same time you will be fine. The NCT imbalance tolerance is pretty forgiving. You overall braking force on the parking brake is fine, so id have a look at the RH side cable. Im not sure how the 323's handbrake is arranged. In some cases you have two cables and in your case it could be as simple as taking the slack off the RH cable.

/edit I did notice that the slave cylinder PN that is cast seems to be different on each side (y4 on one side, y3 on the other). It could just be a differenciation for the side. In any case, its not relevant to the issue you are having, more of an FYI.

Armadillo

Thanks for that SouperComputer, I'll give those a shot and put it through again. I'll let ye know the outcome. :rolleyes:

Darragh29

Armadillo wrote:

Well, I put the 1999 mazda 323 through and it failed on:
Parking - Brake

See printout and pics attached.

I gradually engaged the handbrake (one click at a time) and rotated the the wheels manually by hand - each in turn. On about the 6th click, they locked up.

This is your problem here. A rule of thumb for mechanics is that a handbrake, properly adjusted, should be fully effective and locking the drums at three clicks of the handbrake ratchet. If its taking you six clicks to do this, then the brake shoes need to be adjusted. This is an automatic process on most vehicles. The automatic adjustment mechanism usually is a threaded bar assembly with a few metal springs attached and also a ratchet device, and is specific to the parking brake and not the service brake. I suspect what has happened in your case is that the brake shoes on one side of your car have been automatically adjusting and the other side has failed to adjust as the brake shoe linings have worn. If I was you, I'd adjust the brake shoes manually, there is no point in me going into it here as there is a procedure for doing it and ist the kind of task you'd need to be shown how to do with an example to hand.