ZF6HP21/28/34 (Gen. 2) Vacuum Test Guide
Vacuum testing is an efficient way to identify the root cause of transmission problems and evaluate the effectiveness of repairs. Frequent, proper vacuum testing can put money in the bank, improve turnaround time in your bays, and prevent costly comebacks.
See how easy it is to master vacuum testing and work with confidence knowing your rebuild is done right the first time.
Click here to view PDF if the tech resource does not appear below.
Related Units
Related Parts
Required
Recommended
6R100, 6R60, 6R75, 6R80 (2009–2014), 6R80 (2015-Later), ZF6HP19, ZF6HP21, ZF6HP26, ZF6HP28, ZF6HP32, ZF6HP34
Oversized Converter Release Regulator Valve Kit 95740-05K
OE valve name: WK-V
-
Helps cure:
- Excess TCC slip RPM & related codes
- Harsh TCC apply & release
- Low TCC release pressure
- Rough idle in Reverse
- Harsh downshifts
- Flare shifts
- Overheated converter
Required
Recommended
6F35 (Gen. 1), 6F35 (Gen. 2), 6F35 (Gen. 3), 6R100, 6R140, 6R60, 6R75, 6R80 (2009–2014), 6R80 (2015-Later), 845RE, CFT30, ZF6HP19, ZF6HP21, ZF6HP26, ZF6HP28, ZF6HP32, ZF6HP34, ZF8HP45, ZF8HP55, ZF8HP70
Accumulator Piston Kit 95740-15K
Required
Recommended
Required
Recommended
ZF6HP21, ZF6HP28, ZF6HP34
Oversized Solenoid Pressure Regulator Valve Kit 95740-64K
ZF valve name: DR.REO-V
-
Helps cure:
- Delayed engagement
- Flare shifts
- Harsh downshifts
- Neutral shifts
- High line pressure
- Harsh upshifts
- Wrong gear starts
- Gear ratio & solenoid codes
- TCC slip
Required
Recommended
ZF6HP21, ZF6HP28, ZF6HP34
Oversized Clutch A & Clutch E Control Valve Kit 95740-72K
Fits either clutch A or E control bore locations in E-shift versions of ZF6HP21/28/34 (Generation 2) valve bodies only.
-
Helps cure:
- Coastdown Neutral
- Downshift bind-ups
- Harsh downshifts
- Flare shifts
- Pressure control out-of-range codes
Required
Recommended
ZF6HP21, ZF6HP28, ZF6HP34
Oversized Pressure Regulator Valve Kit 95740-69K
ZF valve name: SYS.DR-V
-
Helps cure:
- Poor shift quality
- Low line pressure
- Flare shifts
- High line pressure
- Harsh shifts
- Burnt converter
- Delayed Reverse
- No Reverse
- TCC slip
Required
Recommended
ZF6HP21, ZF6HP28, ZF6HP34
Oversized Lubrication Control Valve Kit 95740-71K
ZF valve name: SCHM-V
-
Helps cure:
- Bearing failure
- Bushing failure
- Planetary failure
- Lube failures
- Low converter pressure
- Overheating
- TCC codes & concerns
- Rough idle in Reverse
Required
Recommended
ZF6HP19, ZF6HP21, ZF6HP26, ZF6HP28, ZF6HP32, ZF6HP34
Oversized Position Valve Kit 95740-75K
Fits E-shift versions only of the ZF6HP21/28/34 (Generation 2) and ZF6HP19/26/32 (Generation 1) valve bodies with an 053 separator plate.
-
Helps cure:
- Shift concerns
- "A" Clutch burned
- B Clutch burned
- E Clutch burned
Required
Recommended
6R100, 6R60, 6R75, 6R80 (2009–2014), 6R80 (2015-Later), ZF6HP19, ZF6HP21, ZF6HP26, ZF6HP28, ZF6HP32, ZF6HP34
Converter Release Regulator Valve 95740-05A
While Sonnax makes every effort to ensure the accuracy of technical articles at time of publication, we assume no liability for inaccuracies or for information which may become outdated or obsolete over time.