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  • UD Clutch distress
  • OD clutch distress
  • Loss of lube oil
  • Uncontrolled clutch pressure & cycling
  • Flare shifts
  • Low line pressure
  • High line pressure
  • Soft shifts
  • Harsh shifts
  • Low converter pressure


Pressure regulator bore wear creates line pressure instability. This affects the solenoid feed, lube and converter control.


The Sonnax oversized pressure regulator valve restores OE line pressure control.


Reamer kit F-41954-TL is no longer in production but may be available from distributor inventory

A5GF1, A5HF1, F4A41/42/51, F5A51

Oversized Pressure Regulator Valve
Part No. 41954-01K

You need this if... View Instructions

If wear in Mitsubishi F4A and F5A applications occurs at the balance/inboard end, the valve will not stroke to reduce line pressure and reduces feed to the converter/lube circuits. This can result in high line pressure, harsh shifts, reduced converter pressure and loss of lube. Severe wear at the other pressure regulator valve circuits can allow line pressure to exhaust, resulting in low line pressure, soft shifts and burnt clutches and bands. Sonnax oversized pressure regulator valve kit 41954-01K restores the valve body to normal operating condition.

  • Valve is hardcoat anodized to reduce wear

May be used in Mitsubishi front wheel drive, 96-later valve bodies including F4A41/42/51, F5A51 and Hyundai/Kia A5HF1 and A5GF1. However, OE valve spool diameters MUST be measured to verify application. This kit CANNOT be used in rear wheel or all wheel drive units.

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Mitsubishi F4A, F5A Valve Body Layout

Mits f4a f5a thumb
  • 41954 01k combo
  • 41954 01k
  • 41954 01k measurenote

You need this if...

A vacuum test at the port indicated fails to hold at least 18 in-Hg.

  • 41954 01k test