the 1988 model IRS is it the second generation and does it have to be removed to do a complete brake job

 

You should be posting in the "XJS" section, but anyway.....

An '88 XJS will have the first generation, inboard brake IRS

A full brake job, including calipers and rotors, can be done without removing the IRS of you can get the car high enough ....as the lower arms must swing wayyyyy down to allow clearance to remove the rotors.

Almost everyone just drops the IRS, though.

Cheers
DD