RS250 brake issue

Hello all First Post on the forum and hoping someone out there can help.
My sons 2010 RS 250 has a brake issue that is driving me mad. The car pulls to the left under brake when applied. Difficult to describe the actual sensation but it tends to dip / dive to the left when brakes are applied reasonably hard The car has new discs and pads all round , front calipers have been totally rebuilt including new link pipes and has new rear calipers. The car was moted last week and we noticed that the brake pressure values were higher on the left side front rear and handbrake. The brakes have been fully bled. No suspension issues were noted during mot and I haven't found any play anywhere in the system . One thing to note is when prssing the pedal to bleed the brakes when the nipples are cracked on the right side of the car the pedal with a nice smooth feel but on the left it takes a lot more force the depress. Flow from the nipples seems consistent on both sides Under normal conditions the brakes seem fine Any ideas what could be the issue Any help appreciated

 

Should also have mentioned that the wheel alignment has been done so have ruled that out as a cause too

 

Thanks for your reply There is documentation we got with the car regarding lower arm bushes replaced from 2019 but does not state if both or one side was done. The car was only moted last week with no advisories and I've checked as best I can if there us any play and couldn't see or feel any I suppose for £100 or so would be worth doing. Thanks again RSrowe

 

Yes should have posted a response . Our issue turned out to be a damaged / partially collapsed flexi line. Replaced with braided lines and now the car brakes perfectly as it should with new discs and pads all round new rear calipers, rebuilt front calipers , braided lines and of course fresh fluid in the system!! Hope this helps and you get sorted.