TransLink's new fleet of 39 trolley buses has been out of service for almost one month, and the transit company's mechanics can't figure out what's causing the vehicles to lose their power steering.

The trolleys were grounded late in January when some drivers reported a temporary loss of power steering at intersections.

TransLink spokesman Ken Hardie said Vancouver's trolley buses are custom made and complicated, and every trolley bus the company has bought since 1948 has come with technical difficulties.

"Obviously, it's unfortunate, because you want to have as much service out there as possible, particularly when there's so much demand for transit service. However, this is one of those situations that is not uncommon," Hardie said.

He disagreed with the suggestion the lack of trolleys has meant longer waits for commuters.

"We have not been overwhelmed by complaints from people noticing long waits between buses or excess crowding. The system is crowded anyway."

On its website, TransLink said it has borrowed buses from Coast Mountain Bus Company, formerly known as BC Transit. Coast Mountain is a subsidiary of TransLink.

'Creative rescheduling'

"With those buses and some creative rescheduling by Coast Mountain planners, it appears from the daily service reports that the impact on transit customers is being minimized as much as possible," TransLink said.

"Nonetheless, we are grateful to our customers for their patience and to the media for helping convey this message."

The steering problem is covered by warranty. A representative of the manufacturer, New Flyer Industries of Winnipeg, has been brought in to help fix it.

The first of the new trolley buses hit the streets of Vancouver last summer. TransLink has ordered a total of 228 -- 188 standard 12-metre buses and 40 articulated 18-metre buses -- at a total cost of $273 million.

Trolley buses have been on the road in Vancouver since 1948; they normally move nearly 250,000 passengers a day.