My '67 OTS will pull to the left OR the right when just starting to drive (even on warm day). Once I've been driving a bit, problem goes away and there's no more pulling to one side or the other.
Replaced master cylinder recently to remedy problem but this has had no impact.
Could it be vacuum servo? Don't seem to be losing any brake fluid but I've heard that even a small leak in the servo can have bad consequences.
After decades of driving civilian cars, I got back into old English cars a couple of years back. Used to work on my '59 TR3 and my father's '56 XK140 when I was in high school in late 60's. Currently have the '67 OTS (restored 20 years back by previous owner) and a '66 FHC (lots of miles but nice shape).
Thanks for any help with this unusual problem.

Submitted by tidewaterinsp@… on Wed, 06/26/2013 - 16:34

No it would not be the vacumn servo. All that does is give you power brakes.
If the car is not driven much you may have calipers sticking cold. It also does not sound like a metering or proportioning valve problem. Your car likely has neither of those as it is 4 wheel disc brake.
Another possibility is a flex line that is not leaking externally but is starting to collapse internally. You only have flex lines on the front and the front is where you really feel pulling from uneven braking from whatever source.
Food for thought.
Hope it helps.
Scott S