1985 90 brakes sticking on when engine warm

Hello my Landy has recently been completely refurbished and it has developed an unusual problem. sometimes when the engine gets up to temp the brakes stick on more and more until you cant drive at all and the brake pedal goes very hard. when you leave it all to cool down it goes no problem again.
I tried replacing the front callipers but it hasn't helped my next plan was to change the master cylinder any advice would be appreciated.
Thanks

I think your brakes are binding..I suppose it’s maybe coincidence the engine is warm from a few mins running and the brakes are warming up from the motor on the move. Drums rear and discs front? Try checkin the brakes are bled and something daft like a pad hasn’t came off and jamming up. How healthy is the vacuum pump. Strange one mate but that’s those effin landy for you

Brake master rod adjustment/free play is incorrect. Given recent refurb most likely the issue.

Forrest Gump said:

I think your brakes are binding..I suppose it’s maybe coincidence the engine is warm from a few mins running and the brakes are warming up from the motor on the move. Drums rear and discs front? Try checkin the brakes are bled and something daft like a pad hasn’t came off and jamming up. How healthy is the vacuum pump. Strange one mate but that’s those effin landy for you

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Thanks for your reply. it is drums on rear and disks on front indeed Im pretty confidant the brakes are bled correctly, however the vacuum pump dose seem to have a little bit of oil weeping in that area if that could cause the brakes to lock on it could be worth investigation.

tottot said:

Brake master rod adjustment/free play is incorrect. Given recent refurb most likely the issue.

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Thanks for the reply. I did try giving the brake pedal more "slack" with that rod adjustment but admittedly I didn't know how to adjust it correctly do you know the proper way to set the rod?

Only 2/3 mm free play needed at the rod/master contact. This works out at roughly 13mm at the pedal. Do it by hand and you should feel the moment rod contacts the master piston.