Parallel cooling circuits do not automatically receive equal flow. Differences in channel length, diameter, elevation, fittings, deposits, and manifold position can send most coolant through the easiest path while critical zones remain hot.
Each branch should be checked for flow and inlet-to-outlet temperature change. Identical outlet temperatures do not prove equal cooling if flow rates differ. Balancing valves or calibrated restrictors may be needed, but they should be adjusted from measured branch performance.
The manifold should distribute coolant symmetrically and allow air removal. Circuit identification must match the tool drawing so maintenance changes can be traced. Increasing total pump flow will not necessarily correct a branch that is hydraulically bypassed.