The Professional Firefighters' Union is calling for the repair of an entire fleet of fire trucks, which it says is riddled with faults.
Last week the union stopped using the Pump Rescue Tender vehicle in Auckland, and from today fire fighters in Christchurch are doing the same with their truck.
A union spokesman, Boyd Raines, said the faults had been apparent since the MAN-branded fire trucks were first introduced last year.
"At this stage they've got about 27 out there, and of those 27, all have pretty much generic faults and also some specific faults to that truck; not going into gear, trouble starting, trucks just stopping for no apparent reason."
He said more than 200 faults had been reported with the new trucks across the the country, and included everything from broken door handles, to faulty throttles and water containers.
Mr Raines said the faults created a risk to both firefighters and the public and urgently needed to be fixed or taken out of use.
"There's been a huge amount of frustration amongst firefighters who are riding these appliances and the best thing would be to get them fix to a standard we're happy with."
Fire Service deputy national commander Paul McGill said there had been several faults with the MAN-branded appliances since they were introduced throughout the country early last year.
He said the service was doing all it could to fix the problems.
"We've invested a lot in these appliances and we've bought the best we could on the market from very reputable companies, and we're frustrated too by the series of problems we've found, and we're working very strongly with those suppliers ot get them addressed - it's all being done under warranty - and we're working through those as quickly as we can."
Mr McGill said he was confident the nature of the faults would not put fire fighters or the public at risk, which is why they had not taken the trucks out of service.
He said the faults applied to all of the vehicles because they're exactly the same make.
"It is a new vehicle type, but we used the same appliance builder that we have for many years and we've had a very reliable service from them. The issues come really around the advanced technology on the vehicles, the cab chassis, the pumps, the body themselves, are all computer driven with electronic communication between those different items that make up the vehicle, and that's where we're experiencing our most difficult problems, it's getting those computer signals sorted," he said.
Mr McGill said the problems were unexpected.
"The vehicle underwent extensive testing before it was introduced into one station for a few months, but despite all that extensive testing on the first vehicle that came out, the faults we've identified now didn't present themselves and some of them took several months to present themselves."
Professional Fire Fighters' Union spokesman Mike Gillon said he thought the trucks were built poorly and were "falling to bits", with everything from pumps not working to handles coming off hinges.
He said fire fighters had become so frustrated with the faults, some avoided using them if they could.
"We want to be able to trust our new gear, and there was an example of an appliance, and it was getting fixed and the [fire fighters] were in no hurry to actually get it back on the run. They actually preferred to use the old trucks. You wouldn't find that very often in any sort of job where you'd prefer to use the old stuff, rather than this latest and greatest," he said.
He wanted to see the MAN-model trucks pulled completely.
"I would like to put a halt to actually building more MANs, I'm at a station where we're supposed to be getting a new MAN next, but they're holding back on them now, but we'd actually prefer them not to fix them at all and just keep the [old trucks]."