The OE boost valve and sleeve seizes or becomes damaged. The OE boost sleeve is made of plastic, which can easily be cracked or broken when the sleeve is being removed from the valve body
The Sonnax replacement boost sleeve is made of wear resistant aluminum to increase durability. The boost valve is designed to maintain OE pressures when used with the OE clutch A control valve.
ZF6HP19/26/32 (Gen. 1) and Ford 6R60, 6R80 transmissions are equipped with a plastic sleeve for the clutch A control boost valve. This material is prone to damage, especially during removal. Failure of this sleeve results in delayed or harsh forward engagement, flare 5-4 downshifts and no 4-5 upshift. The Sonnax clutch A control boost valve and sleeve kit 95740-21K will restore the 4-5 downshift function, correct the missing 4-5 upshift as well as correct forward engagement problems. The Sonnax boost valve and sleeve kit can also be used to replace an OE boost assembly that was damaged during disassembly and must be used with the OE clutch A control valve.
Kit is NOT compatible with ZF6HP21/28/34 (Gen.2) units. To differentiate between Gen. 1 and Gen. 2 valve bodies, see ZF Identification Guide.
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.
October 24, 2014
Topics: Transmission Ford 6R80 Transmission 6R60 Transmission 6R140 TransmissionRead Now
June 29, 2016
Topics: Diagnostics And Theory Transmission ZF ZF6HP19 Transmission ZF6HP26 Transmission ZF6HP32 Transmission ZF6HP21 Transmission ZF6HP28 Transmission ZF6HP34 TransmissionRead Now
January 14, 2014
Topics: Identification Guides Transmission Ford ZF ZF6HP19 Transmission ZF6HP26 Transmission ZF6HP32 Transmission ZF6HP21 Transmission ZF6HP28 Transmission ZF6HP34 Transmission 6R80 Transmission 6R60 TransmissionRead Now
January 21, 2013
Topics: Vacuum Test Guides Vacuum Testing Transmission Ford ZF ZF6HP19 Transmission ZF6HP26 Transmission ZF6HP32 Transmission 6R80 Transmission 6R60 TransmissionRead Now
June 22, 2016
Topics: Vacuum Test Guides Transmission ZF ZF6HP19 Transmission ZF6HP26 Transmission ZF6HP32 TransmissionRead Now
Contact a Sonnax Parts Distributor.
A vacuum test at the outer port fails to hold 16 in-hg of vacuum, but the inner port does hold 18 in-hg. If the inner port does not hold 18 in-hg vacuum, you must use the oversized clutch A control valve kit [95740-09K] to repair the valve body.