Series 3 Brakes pulling

Hi,
Would appreciate some advise as to what to look for , basically after say a day of of inactivity when I first apply the brakes the vehicle pulls dramatically to the left , after one or two stamps on the brakes all is well & pulls straight and true . However that first stamp is quite dramatic . Embarressingly it's been like this for nearly a year since I got it , I just ensured I did a first controlled brake in the drive before I hit the road. But I sort it out before something happens . Plan to get the front drums off today , and any advise as to what to look for would be much appreciated .
Cheers
Steve

its not unusual, oil and adjustment

Slave cylinder pistons can stick.

If it pulls to the left, could well be oil on the right side drum. Or brake fluid, which is slippy when fresh, but sticky when it's been there a while. Oil is easy to fix; brake fluid less so. Good luck.

Mine did this, was a leaking cylinder on one side at front. Couple of hrs to replace. Just use quality parts

If your pulling to the left, check:
Does your break fluid drop/need topping up every month or so? = RH Leaking cylinder
Check RH Hub oil seals, if they fail you'll get oil contamination of the brake shoes.
Also make sure the springs on the RH side are fitted correctly, fitting the rear top spring from shoe to shoe and not from shoe to back plate will cause what you have described. Reason is if the spring is fitted between both shoes it will cause the slave cylinder to fully contract and need at least one full pump of the brake pedal before pushing both shoes out enough to firmly contact with the drum.