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Sonnax 77898E-14K Boost Valve Kit 4L60E 4L65E 4L70E Late pump design, .421" dia

by Sonnax
Sold out
Original price $34.61 - Original price $34.61
Original price
$34.61 - $34.61
Current price $34.61
Out of stock

Delivery time

You will receive your package in 2–5 business days within the contiguous U.S.

Country/Region of Manufacture: United States

OE Spec or Performance/Custom: Performance/Custom

Manufacturer Part Number: 77898E-14K

Brand: Sonnax

Manufacturer Warranty: No Warranty

4L60-E, 4L65-E, 4L70-E

Boost Valve Kit
Part No. 77898E-14K

Late pump design, .421" dia, O-ring style with OE ratio

GM 4L60-E, 4L65-E and 4L70-E transmissions frequently have poor line rise, which can result in 3-4 clutch, 2-4 band failure or poor shift quality. The duty cycle of the EPC solenoid causes the boost sleeve to wear quickly. Oil entering the torque signal orifice leaks past the boost valve and exhausts at the Reverse orifice, resulting in poor line rise. Reverse oil can exhaust both to the sump and back through the torque signal orifice. The outside diameter of the boost sleeve also allows some leakage through the pump body, which decreases pressure rise.

Sonnax boost valve kit 77898E-14K is a standard OE ratio assembly that will restore hydraulic integrity and prevent leakage in units with late-design pumps. Drop-in Zip Valve™ parts install quickly and easily. See chart for usage details and other boost valve options.

  • Valve 3 Grooves, .421" dia.
  • Sleeve
  • O-Rings (3) 1 Extra

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