Hi moontan002!
First off,
"WELDCOME TO THE WORLD'S GREATEST WELDING FORUM!!! :) :) :)"You need to read the Lincoln "Under Cooler Cart" operation manual, especially the maintenance and troubleshooting sections... If you weren't aware of the yearly required maintenance on the pump, you may have a pump inlet strainer screen that's full of debris if it wasn't periodically checked for any built up debris on an annual basis as recommended in the IM 723-A operation manual for the Under Cooler Cart... Here's the link to the .pdf manual:
http://content.lincolnelectric.com//pdfs/products/navigator/im/IM723.pdfIf your pump inlet filter is clogged, then you may only have partial flow of coolant through the hoses and they're ballooning up in size due to overheating because of this...
If you have not done any of the required periodic maintenance as written in the IM723-A operation manual in the maintenance section, then you're probably more than due to take a detailed look at the pump and heat exchanger as wellas replacing the collant completely which is also required on a yearly basis too.
If you haven't done any type of yearly required maintenance, you could be told by the Lincoln reps that your under cooler cart warranty is voided because of neglect... So I would strongly recommend that you carefully read the above posted operation manual for the under cooler cart, and start looking at the pump, pump strainer, pump inlet filter, pump oil level, completely replace the coolant, follow all of the steps written in the manual and see if the condition disappears!!! ;) If it doesn't, at the very least, make sure that the pump has new oil in it, the filters and strainers have been cleaned to be free of debris, the fittings behind the screens are free of any built up debris and the coolant is fresh and replaced completely along with the addition of the bacterial growth preventive additive before any Lincoln rep has a chance to take a look at your 2 machines - CAPECHE???
So at the very least, read the manual in this post and do the required maintenance to see if you can correct the problem and if it does correct it, then from now on follow the required maintenance activities from the manual and adhere to them religiously in order to prevent this from happening again! ;)
Respectfully,
Henry