Caterpillar Inc’s (CAT.N) suppliers were feeling the pain of slumping sales at the world’s largest mining and construction equipment maker long before it announced an extensive cost-cutting program. J-TEC Chief Executive Officer Gary Roling said Peoria, Illinois-based Caterpillar, his single largest customer, had recently pushed back a big order due this month to December. “We’ve been selling to Caterpillar for a long, long time, and this year will likely be the lowest year for sales we’ve ever had,” said Roling, whose company makes tools to measure the flow of fuel, exhaust and other gases.