GM 4L80-E and 4L85-E pressure regulator valve design prevents adequate cooler flow at low RPM and high pressure/demand conditions, which can create overheat complaints. In ‘99-later vehicles, the factory EPC pressure was set high at idle, resulting in engine surge conditions. Sonnax oversized line-to-lube pressure regulator and boost valve kit 34200-36K provides a significant increase in cooler flow under low RPM and high pressure conditions.
February 21, 2013
Topics: Vacuum Testing Vacuum Test Guides Transmission GM 4L80-E TransmissionRead Now
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A vacuum test at the port indicated fails to hold at least 14 in-Hg.