ABS problem on Urq

[Ado Sigal]

Hi all

Strange problem developed lately on my 86 Urq. After swapping the callipers for G 60, changing the fluid and bleeding
the system, the ABS unlike before, comes in at every stop, with usual pedal rattle, then a little hydraulic gargle,
after which pedal dips and then returns to normal pedal position. On Motorway, ABS switches itself off after about five
min. while not using brakes at all. Switching ABS off, brakes work perfectly. Changed ABS relay with known good one,
same thing. All el. connections are fine, hydraulic fluid new and fibre filter clean, no leaks anywhere. Help needed.TIA .

Merry Christmas, and bestest New Year to you all.

Ado Sigal