Posted 23 May 2008 - 12:16 AM
Hi Sandyrun Welcome to the board!! That hose that goes from the Tee to the valve sends the excess lube oil back to feed the charge pump, when the charge pump needs no more, the valve opens & dumps the oil into the trans case. If the lube valve gets a piece of debris from somewhere downstream of the pressure filter, it will stick open & the charge pump won't lift the oil from the mainframe, it will suck air out of the trans case. The problem is worse on later machines with the suction screen & pressure filters in the fender compartment to the left of the seat. The pump has to lift the oil about 4 ft to go through the suction screen. The lube valve can be accessed under the seat, it's the only spool in the regulating valve with with a pipe plug at one end, you will need a new gasket for the cover plate. The early B models had a safety filter between the torque convertor & lube valve feed hose on top of the reg valve to catch any nasties the came from the convertor. I would carefully examine the pressure filter paper for evidence of any particles, bearing material or aluminum, may be the torque front turbine bearing giving problems. You can hook a vacuum guage into the top of the suction filter, if there's no vacuum, then it's sucking air, maybe the lube valve if the rest is good. Hope you find something simple. Regards, Russell
From the Okanagan valley in beautiful British Columbia, maybe THE place with the highest concentration of IH crawlers and according to IH, when they were going strong, some of the toughest conditions for logging equipment, they sent a lot of machines to southern BC to R&D!! IH/Dresser Mechanic since 1987, a few before that too, TD25's are great, TD20E's sound awesome!! Worked on TD5's to TD25G's. TD15C number 501, the very first one is still working near here. I have a Hough model 12 track loader S/N PL12-647 and a TD15-151, S/N 4864.