Cooling System Pressure Cap Rating

[welshandy]

I bought a 1994 3.0L V6 auto Camry recently off of e-bay and have been having a lot of probs with cooling system, basicly overheating on journeys of 30 miles or more, thanks to help from a previous post several faults found, 1) resivoir tank leaking. 2) water pump u/s. 3) hydraulic cooling fan switch also u/s.

These have been sorted but still having problems. Sometimes the system does not draw back coolant from resivoir tank back to cooling system when cooling down, also seems to expell coolant from system to resivoir tank after only 3-4 miles.

Is this a problem with the pressure cap,was changed by previous owner. It has a 0.9 written on cap is this the bar rating and if so is this correct for the engine (3VZ-FE)? As checking the Haynes manual which has the rating in psi converting to bar sugests a rating of about 1.2bar . HELP