1986 300E Steering Box seal leak in winter
 

The past two years I have replaced the two blue seals in the summer but in winter when the temprature drops down to -30c or so one of the seals blows.
I read in another thread that this iis probably because of the pressure control valve.
Will the procedure at http://www.davidpetryk.net/Mercedes/Steering.htm
effectively fix the pressure control valve issue ?

This summer I will be doing the whole job as per the link.

I have considered getting this

http://www.autopartsway.ca/autoparts/wizard.cfm?ID=1986~MB~300-E-002~All~Steering+Gearbox~appChassis=B000000-B022104

Thanks