Steering Rack Issues

[NICKCEFFY]

Not sure if this is the right section but hopefully someone can help or point me in the right direction

help guys got a major issue and scratching my head with whats going on.

Car

180 sx

Engine

RB 25(relocated back 50mm)

Steering pump

rb20

Steering rack

s13 & r32 (relcoated forward 20mm and up 8mm

Steering lines

Custom high pressure line

New low pressure to small cooler into resevoir

So the problem i've had with both racks, is once i get the rack in and bolted down the car running a bleed the system by turning the wheels it feels all good then once i leave the wheel an top the resevoir i come back to turn the wheel again and it will just pull out of my hands and then rack back and forth uncontrollably then once i turn the car off the rack now feels real tight and won't return to 'normal'

The motor is relocated back and i would only have 3-4 mm clearance between the sump and the rack but it doesn't feel like there is enough heat in the sump to affect the rack or cause air bubbles, the system has plenty of fluid and as said the cooler so now i'm clutching at straws to know what is wrong and how to fix it.

So if anyone has any ideas please fire them my way, i'm open to anything and will try any suggestions if i haven't already

cheers

Nick

[Duncan]

you replaced the rack....did you try replacing the pump? sounds like it is dying and pushing variable amounts of pressure