I've just put crossover and hydro assist on my '91. Am I right in thinking that the power steering pump has to be able to breath? I've made an extension for the filler neck but am not using the standard cap. When i rev the motor the extension tube collapses and the pump makes an horrible noise. If I losen the cap off it sems ok. It looks like the standard cap has a tiny vent tunnel in it under the seeling washer, correct? Second question is, when I used to get to full lock the pump would make that tell-tale hum so you knew you were at full lock, but now the ram just wants to bend the tie rod and the pump doesn't make any noise! I did the basic mods to the pressure valve but nothing too drastic. It actually flexes the tie rod easily at idle....goodness knows what it'll do to it at higher revs. I can't see the TRE's lasting long! Anyone else had this problem? Have I built too much pressure into the pump? Any thoughts appreciated guys!