Hi VickyG
Don't know if I'm too late with this, digging around Online regarding my forthcoming caliper rebuild, and had seen your post about master cylinder a few days ago.
Found a master cylinder repair kit apparently for 940 I was searching for bits for mine a 1994 model
Found Bigred in Uk £16.25 inc vat, presume plus post.
https://www.biggred.co.uk/volvo-940-...ir-kit-brm1322
Hope it may assist.
Cheers
Steve