I have a MF35 1960 perkins diesel I rebuilt. After startup I get power steering fluid coming out of the breather vent that is just behind the steering shaft and on top of the steering housing. I took out the o rings on the cylinder assembly and replaced the 2 o rings that go on the assembly adapter. Tripled check the conditon of the o rings before finally seating the assembly in the cylinder housing and put all back together. Started again and same results, fluid coming out of the breather vent. I made sure the power steering fluid was full in the power steering pump. The pump, pumpes it out but does not return the fluid back to the pump, just keeps coming out the breather vent. Any help would be appriciated. Thanks, John