Have a early serial number mf135. The steering was very hard. Replaced the pump (round with upright reservoir) This works for a while then gets very hot and pushes oil out the seals on the gear under the steering column. Changed it out thinking the seals were weak, run tractor and still the same. Do not find a way to adjust pressure on the pump but seems to be way to hi as when you turn the wheel the hoses jump a bunch. Any Ideas?