G4A-EL, G4A-HL, GF4EAT

Symptoms:

• High EPC pressure
• Low EPC pressure
• High line pressure
• Low line pressure
• Erratic shifts

Cause:
The constant oscillation of the steel pressure modifier valve wears the bore, resulting in loss of valuable EPC oil.

Correction:
Seal oil at the balance end of the pressure modifier valve to correct line pressure. Seal line pressure oil at the middle spools to prevent low line pressure.

When the balance spool bore in Mazda G4FA-EL units wears, the valve won't stroke to regulate EPC pressure. If the middle spool bore wears, line pressure will be allowed to exhaust. Sonnax oversized pressure modifier valve restores hydraulic integrity to the circuit by sealing these locations in the bore.

It is highly recommended that the pressure regulator bore also be checked for wear. A worn pressure regulator bore can result in low/high line pressure, harsh shifts, lack of cooler flow, and/or blued converters. The Sonnax offers an oversized pressure regulator valve to restore the integrity of a worn pressure regulator bore.

• Valve is manufactured from anodized aluminum for improved wear resistance
• OE spring can be reused thanks to shortened spring seat depth that compensates for the oversized valve

Note:
Must measure OE valve small diameter before reaming. OE must be .357" It is highly recommended that the pressure modifier valve bore be checked for wear on the GF4A-EL unit as well. Sonnax offers anoversized pressure modifier valve, which can be used to refurbish bore wear at this location.

SONNAX Installation Instructions