Replaced the leaking wheel motor seals and after only about 5 hours one is leaking again. This machine uses an automotive radiator cap on the fill tube on the Hyd tank. Most any Hyd tank I've ever seen is vented to atmosphere not sealed with a 7psi pressure cap. I'm wondering if the pressure is building up in the system and blowing out the wheel motor seals? Seems like an odd setup.
Actually I think automotive radiator cap should hold 30-40 psi pressure, but if you measured it at 7 than it is 7. If your system uses piston pump the tank should be pressurized a little, when you will be replacing this one - check shaft for wobble and shaft surface where the seal rides on for scratches, grooves and other damage or wear marks.
did you just replace the seal or bearings to. if your just blowing that seal something is causing it not to run true I suspect. not real familiar with mustangs but when I replaced my seal on a case I replaced the bearings also.