The businesses have grown over two decades to a staff of almost 40 across the two companies. Central Diesel Services is the authorised service and repair agents for Cummins, Mercedes Benz, Freightliner, Stirling and IVECO truck engines.
Mr Haden was born in Tauranga and initially lived in Katikati where his father ran the Caltex service station.
But when he was 6, his father moved the family to his birthplace in Ruatoria, to take over the family general store.
"It had its challenges," said Mr Haden, who grew up and went through primary and secondary school in the isolated rural community.
"The opportunities were very limited when I grew up there 40 years ago," he said.
"I think it made me want to get out in the world and look for opportunities and prove I could do something."
He left Ruatoria at 16 to take up a three-year apprenticeship as a diesel technician in Gisborne, then moved to Auckland where he worked for Cummins for two years. He left for a four-year OE, which included stints in the US and the UK and a period repairing engines for a charter-boat flotilla in Turkey.
On his way back, he stopped off to work in the mines in Western Australia and raise funds to bring a Ford Corvette he had bought in the US back to New Zealand to restore.
At that point he and his wife Debbie moved to Mount Maunganui where he started a Cummins branch with another partner. After three years an opportunity came up to start a Tauranga workshop with International Trucks Australia Ltd, maintaining International Harvester trucks for the dealership.
"Being young and crazy, Debbie and I took on the challenge," said Mr Haden.
Central Diesel Services was set up in 1995 and after five years the businesses had grown to the point where both needed their own identity and space. Meanwhile, the Hadens had another opportunity to become the dealer for Cummins.
"Their branch had by then closed and they asked us to become the agent for Mount Maunganui and Tauranga."
As part of the process they bought Mount Auto Electrical, then in receivership, and brought in Richard Farminer to run the electrical side of the business while Mr Haden focused on truck engine repairs. After about two years, the business had grown and he moved the mechanical and engineering business to its present location in the Page Macrae building. In 2009, Mr Farminer bought a 50 per cent stake in Mount Auto Electrical.
In 2006, Tidd Ross Todd, a Hamilton-based business, which among other interests held the Mercedes/Freightliner truck franchises in the Mount, asked Central Diesel Services to come in on a joint venture.
"They had a couple of managers come and go, and were struggling a bit," he said. They began with a 50-50 joint venture, which eventually became a merger with Central Diesel Services buying out Tidd Ross Todd in 2012.
The businesses were brought together in the Page Macrae site, which underwent a major revamp with a new purpose-built parts centre and retail counter, two new drive-through lube bays and brake rollers, picking up the Mercedes, Freightliner and Detroit franchises.
Although the merger brought significant challenges in putting the two cultures together, these were eventually resolved. This November, Central Diesel Services will celebrate its 20th year in business.
Staples Rodway partner Mark Robinson, who has been Mr Haden's financial adviser for many years, said a key to Mr Haden's business success was that he was someone people liked dealing with. "He really values people, both customers and his team," said Mr Robinson.
"He's very down to earth, extremely hard working, but has a great sense of humour and humility."
Unified culture brings steady growth
Bringing together the two working cultures of Tidd Ross Todd and Central Diesel Services was hard, says managing director Bert Haden.
"They were very different cultures and the guys that came from Tidd Ross Todd had effectively been running on their own without a manager for a while," he said.
"At that stage Central Diesel Services had long-term staff with a good work ethic. The people who joined were out of their comfort zone and joining a new environment ... It took a fair while to sort all that out."
The first years of the joint venture from 2006 were a struggle and were not helped by the onset of the global financial crisis.
Eventually, the companies formally merged, with Central Diesel Services taking out Tidd Ross Todd's interests in 2012 and growth has been steady since.
Mr Haden noted skilled people were hard to come by, especially those with product experience.
Tidd Ross Todd brought with it a number of new franchises and people with specialised knowledge, which the merged business needed to retain.
One key process which helped meld a unified culture was taking part in the 2013 High Performance Work Initiative, sponsored by the Tauranga Chamber of Commerce and the Ministry of Business Innovation and Employment.
"We were still dealing with some of the consequences of the merger and we wanted to get the culture correct," said Mr Haden, commenting on why Central Diesel Services took part in the initiative.
"One of the main things we took on board was the need to set company values and vision.
"We had all the staff involved with that. Everybody in the team has helped us come up with our values and they are holding each other accountable to those values.
"Getting the communication working better certainly helped us a heap and still is today."
Two work together
Bert Haden and his wife, Debbie, live in Oropi on a 2ha lifestyle block they bought in 2000 and have been developing into an avocado orchard, with 200 trees planted.
"We've got a boat and I like to go fishing," Bert said. "But like most fishermen, I don't do enough of that."
They have two sons at home, a son at university and an eldest daughter who is about to do her OE.
"We did a major revamp of the house, and the orchard and the kids keep me pretty busy," he said.
Debbie is co-owner in the business and an active director who helps out from time to time with administration when needed.
"She's my sounding board," said Bert.
"It's good to have someone like that who's not emotionally involved in issues and can look at the business objectively."
Bert Haden
Role - Managing director, Central Diesel Services
Born - Tauranga, New Zealand
Age - 47
First job - Apprentice diesel technician
