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Jerry, Master Mechanic
Category: Mazda
Satisfied Customers: 17220
Experience:  ASE Master certified, 30 years experience. Auto troubleshooting, electrical , ABS, SRS, EFI system
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1998 mazda B4000: fuel filter..fuel pressure..crank..fuel system

Resolved Question:

1998 mazda B4000, trying to replace fuel filter, can't get fuel pressure to release. Disconected inertia switch, crank over engine, fuel system pressure still not relieved. Any other way to relieve fuel system pressure?
Submitted: 6 years ago.
Category: Mazda
Expert:  Jerry replied 6 years ago.

Hello and welcome to Just, Super mechanic here. About your vehicle.


  1. Remove the Schrader valve cap and attach the SST 49 UN01 010 (Fuel Pressure Gauge).
CAUTION: Open the manual valve slowly to relieve the system pressure. This will drain some fuel out of the system. Place fuel in a suitable container.


Open the manual valve on the SST and relieve the fuel pressure.

Another way if you don't have a gauge is to remove the fuel pump connector, fuse or the relay and let the pressure run out by running the engine.

Underhod Location


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