Confirm the pump is running and the flow is not zero. Check that the purge or prime valve is closed. Check that solvent is in the reservoir and that the inlet line and sinker frit are under the liquid. Open the prime path and draw solvent through until the line is full and free of air, then close it and try the method flow again.
A large leak downstream will also show as no pressure. Find it before you keep the pump running dry.
Call Mahut if the pump reports a fault and stops, if you cannot prime, or if there is no pressure and no visible leak after priming. Do not bypass a leak or pressure interlock.