NCT

I Was VB

As some of you may know i recently changed cars. So i have to re tax and re NCT the old car privately as it was a taxi.

So i booked the NCT for the car and it went in last Wednesday (having only passed it 30th Of Jan of this year) But i had to NCT it again. There was about 6K miles from the last NCT, so it failed on frayed front felxible brake pipes. Looked at them and they were badly frayed. The braking performance on the rear axle was 29% and the limit was 30%.

Brought the car back to them today for the retest and it failed on the back rear axle braking performance up, it was 40% and the limit was 30%!!

So im wondering is because of stricter testers? If not then how the hell did the car fail on corroded brake lines in just two and a bit months from being tested and passing?

-Corkie-

Was it a braking imbalance. That new crowd are failing cars for some trivual reasons..

I Was VB

SARASON wrote: »

Was it a braking imbalance. That new crowd are failing cars for some trivual reasons..

The braking pressure that the car does to the back wheels.

slimjimmc

I Was VB wrote: »

As some of you may know i recently changed cars. So i have to re tax and re NCT the old car privately as it was a taxi.

So i booked the NCT for the car and it went in last Wednesday (having only passed it 30th Of Jan of this year) But i had to NCT it again. There was about 6K miles from the last NCT, so it failed on frayed front felxible brake pipes. Looked at them and they were badly frayed. The braking performance on the rear axle was 29% and the limit was 30%.

Brought the car back to them today for the retest and it failed on the back rear axle braking performance up, it was 40% and the limit was 30%!!

So im wondering is because of stricter testers? If not then how the hell did the car fail on corroded brake lines in just two and a bit months from being tested and passing?

Perhaps a sloppy tester let it through the first time when he shouldn't have. Things like this (checks which can't be measured) are subjective, the tester uses his experience and opinion to decide whether or not a brake hose is excessively worn or is likely to become so before the next test date. In border-line cases, two different testers could give conflicting results, just like two different mechanics could have conflicting opinions on whether the testers should have passed it or not.

With regards to the 2nd failure it sounds like brake imbalance got you.
The braking effort between each wheels on the same axle cannot differ by more than 30% and the braking effort on any wheel cannot fluctuate by more than 30%, your's was measured at 40% for one of these. This is measured by machine so the testers have no input in deciding the result.

I Was VB

slimjimmc wrote: »

Perhaps a sloppy tester let it through the first time when he shouldn't have. Things like this (checks which can't be measured) are subjective, the tester uses his experience and opinion to decide whether or not a brake hose is excessively worn or is likely to become so before the next test date. In border-line cases, two different testers could give conflicting results, just like two different mechanics could have conflicting opinions on whether the testers should have passed it or not.

With regards to the 2nd failure it sounds like brake imbalance got you.
The braking effort between each wheels on the same axle cannot differ by more than 30% and the braking effort on any wheel cannot fluctuate by more than 30%, your's was measured at 40% for one of these. This is measured by machine so the testers have no input in deciding the result.

If the 1st tester had said to me to get it sorted with the brake imbalance the 1st time i wouldnt of had a problem getting it sorted, ah well what can be done its going to the mecanic 1st thing tomorrow morning.

slimjimmc

I Was VB wrote: »

If the 1st tester had said to me to get it sorted with the brake imbalance the 1st time i wouldnt of had a problem getting it sorted, ah well what can be done its going to the mecanic 1st thing tomorrow morning.

I appreciate that, but if I saw something on the test results which was barely on the limit it would have prompted me to consider fixing it, especially on a safety critical system.

As for the retest being worse, it is possible the work done on the car could have resulted in further inbalance*, eg. brakes not bled properly after replacing the hoses which weakens one side, or even the opposite... removal of air allows more effort on one side.

Hope you get better results next time.



* I'm assuming it actually is inbalance we're talking as that is the only brake test with the 30% limit you've mentioned.

I Was VB

Well it passed today! Brought it to the Mecanic 1st thing this morning, told them the situation and they blead the brakes and adjusted the shoes.

Telephoned the NCT and they said the soonest they had for a re-test was next Monday! :eek:

So i decided to chance my arm and try to blag my way to get it retested, went up to the reception and told them that i was on the telephone to get it booked and they said just to go up for a cancelation. Waited 10 mins for my name to be called and it passed!!