All of us who operated a forest machine, knows that all machines have one thing in common – they break down, sooner or later. In most cases you can repair it yourself, but every now and then you need to call in the experts. I paid a visit to a service dealer and joined a mechanic to a customer in the forest who had problems. 
The heroes of the forest
I remember the feeling when I eventually had to face the fact that I just couldn´t solve the problem. It was very annoying. It even caused me sleepless nights sometimes. And then, when the expert, the “doctor”, finally arrived in the forest to help me the next fear turned up: What if the problem is something very simple that I should have been able to fix myself but just didn´t see it? What if I made the mechanic come just to push a button, switch a fuse, or tighten a bolt? Every time I realized that the authorized repairman (they were always men in my days) also had difficulties finding the problem, it was a big relief.
A pump breakdown causes problems long after
The operator of a Komatsu 901.4 from 2008, Karl-Ivar Axelsson, had a major hydraulic pump breakdown about a year ago. After that he has had problems with scrap from the broken pump floating around in the hydraulic system. Small pieces of metal can cause damage and make the machine act strange. Last time, it was the main boom that didn´t quite obey the orders from the operator. This time, it was the steering.
The machine suddenly could start steering by itself, in one or the other direction. With his long experience, and knowing about previous problems, he suspected that there was scrap in the steering cylinders. As removing and opening the cylinders is a quite big operation, and as there were more maintenance to be done on the machine, he called N. Bengtsson Skogstjänst AB and asked them to send out their field mechanic Timmy.
N. Bengtsson Skogstjänst AB
The owner of this Komatsu service dealer is Niklas Bengtsson, who also happens to be Timmy’s father. He started off as a forest contractor in 1991 when he bought his first harvester. At the most, he had 8 machines, one truck with machine trailer and 14 employees. In 2011 he bought a workshop for maintenance of his machines. In 2016 he started selling the machines until he had none left in 2017.
After that he started repairing machines for others and in 2019, he became an authorized service- and spare parts dealer for Komatsu Forest. Today, Niklas is working in the workshop with service and repair and selling spare parts. Two mechanics with service buses are working in the field with service and repair. One of them only with forest machines. The other one, Timmy, repair all types of machines, excavators, tractors, dozers, chippers, grinders, etc. and, like this day, forest machines.
Back to Karl-Ivars machine in the forest
When I arrived in the forest, Timmy was already busy dismantling the steering cylinders on the harvester. At the same time, Karl-Ivar was looking over the stump treatment equipment. It looked as if it was going to be a full day of service and maintenance in the forest.
That scrap, small pieces of metal, in the hydraulic system is a problem is nothing new for most of us. When Timmy pulled the piston rod out of the cylinder barrel it was obvious. I’m not an expert but it surprised me that the steering had been working at all.
The scrap had got stuck between the piston and the inside of the barrel and caused major scratches on both. The question now was should it be repaired or replaced with new complete cylinders? Of course, new components are (almost) always a better solution, but in this case … What if there is more scrap in the system and the new cylinders are damaged in the same way?
Decisions must be made
Time is money. A decision had to be made. The possibility to take the components to the workshop and grind them into an acceptable status and just replace the piston seals was discussed. The availability of new cylinders was examined. A phone call to the owner of the machine, Karl-Ivars boss, made the decision – Go for new cylinders!
As those special cylinders were not in stock at N. Bengtsson Skogstjänst AB, Niklas at the workshop was given the task to track down where the closest cylinders could be. However, it turned out they were two weeks away. So, by the end of the day the old cylinder barrels had to be grinded inside, the piston seals were replaced, and the machine was ready to go again.
The problem was solved. The problem had to be solved even if it had to be temporary this time. To make the problem for the customer as little as possible is a major aim for a good service dealer like N. Bengtsson Skogstjänst AB. That is one of the reasons why they have a good reputation.
As for Timmy, he was already booked for over a week ahead, so he just had to go to the next customer with a problem. He is always welcome wherever he goes – the machine doctor.
Photos: Per Jonsson
