Replaced the previously mentioned hoses this morning and... absolutely no difference

I'm sick and tired of this now, what else could it be?

no idea RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar

I have re-read the thread and I don't think there is anything left. If it can't be tolerated then it is time to sell the car.

Very frustrating and annoying though! 2012 Vogue TDV8 in Aintree green over sand

I can't give up Toby, it's either a mechanical or electrical problem which should be fixable.

I will just have to keep trying until I figure it out.

I've been thinking about the pump again, is it possible for the pump to generate the correct pressure but not be delivering the correct volume of fluid?

I understand the tdv8 uses a variable displacement pump but not sure if this type of pump has a flow control valve or not.

I have already replaced the pump twice though.

Once with an aftermarket unit which made no difference to the symptoms but whined terribly and the second time with a supposedly known good used pump.