I apologize for not getting back sooner, too busy as the fields finally dried out. We ran a line off of the hydraulic pump. We elbowed out of the bleed off, through the cooler, then back into the hydraulic reservoir. It's been 150 hours and we haven't had overheating problems. We used this tractor on a bagger, which had a hydraulic driven elevator, also with no overheating of the hydraulic oil. I would suggest calling Brad at Maibach tractor.800-808-9934 He has done a number of these modifications, tested them, and is very willing with helpful advice. Brad could send you fittings, hose, and all the info you need. They are in Eastern Ohio. If I can help you in any way, more details, etc. please advise. Thanks