HMM summat not right -brake machines.

bjmh, Jun 5, 3:39am
i had a problem with local vtnz brake machine. as a last resort i swapped brake drums side to side.voila .inspector happy,mechanic more grey hair

johnf_456, Jun 5, 5:26am
Nothing unusual

unbeatabull, Jun 5, 5:28am
Quite common for shoes to do that, Ive had to swap leading shoes countless times on customer cars to get the rear brake balance within 20%.

skin1235, Jun 5, 6:04am
why should you have to change anything, kaz is pointing out that 3 machines read completely different, ie they are completely unreliable, their figures mean diddly squat

franc123, Jun 5, 6:24am
The only thing not right here was probably the bedding in method, it's unrealistic to get a compliant balance reading straight off after fitting new pads and then "giving it a quick blat up the motoway", some pads require a couple of hundred km of normal braking to bed in completely and give consistant readings, even after the manufacturers instructions have been adhered to, which usually involves several light/medium applications in succession from 70-30 km/h or thereabouts with a cooling interval in between, the point being that too much heat ISN'T being generated.What rotor preparation was done is a factor too, depending on where they were replaced, machined or if they were in really good condition with no grooving or thickness variation, just scuffed with coarse emery tape in a crosshatched pattern.If nothing at all was done expect this process to take a lot longer.

crzyhrse, Jun 5, 6:42am
How many crashes have had as a contributing factor a rear brake imbalance of more than 20%! I mean, really.

Probably the same amount as have been caused by a small stone chip in the CVA but below the line of sight of any driver, except perhaps Gary Coleman, in an otherwise perfectly clear windscreen.

skin1235, Jun 5, 6:45am
" eh what!, are you responding to the 1st post!
you know, where these words are written
"and now 25% with heavy braking. --argggg
Scream up the motorway and give the brakes a good workout. go to ANOTHER brake machine. 15% YAAAY
So back for recheck and -23% --knashing teeth.
No wait a mo--test the brakes on the OTHER brake machine you guys have.
Away we go and 0 then 6% then 17% under heavy brakes - "

and you come up with issue with bedding in!

(shakes head) english is not your first language is it!, and comprehension wasn't in your schooling curriculum

im_andrew, Jun 5, 7:00am
I spent the last week replacing rear brake cyls, rear shoes, contouring and machining drums (twice) on a D22 navara - and got the same 50% inbalance on both the park brake and service brake on the rear axle each time I took it up for a brake test. The cause of the inbalance was the rear tires - dueller M/Ts - one brand new and the other with 4mm tread left. I swapped a brand new one onto the other side as well (so two new ones on the rear) and it came up with a 6% imbalance. The guys at VTNZ insisted that the tread depth shouldnt make a difference, but it did in the end.

franc123, Jun 6, 2:16am
I'm not missing anything, merely pointing out that some pads take a long time to bed correctly and WILL give inconsistent brake readings until this occurs. All three of the machines you used detected imbalance, it was only the degree of it that changed.Did you install them correctly onto unglazed rotors and not hammer the crap out of them instantly, ie not overheat them and make the problem worse!Your first post sounds like it was a case of wham bam thank you ma'am lets get this thing through compliance as quickly and cheaply as possible.Thats something that hasn't been answered yet.

ozz1, Jun 6, 3:02am
brakesmy heart.

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