I reman the db2829, db2831 and ds4 series pumps.
Quick rundown on serial I'd
Db2831; 2 plunger, 8 cylinder, 31mm diameter plungers
2829; 2plunger, 8 cyl, 29mm
Ds4831; 4 plunger, 8 cyl, 31mm
The advance piston is likely not calibrated correctly. The advance piston armature assembly is what...