LOSS OF SPEED HARDSHIFT 700-R4 CRUISE CONTROL FIX

Model and Year 1982-83 IMPALAS AND CAPRICES

Some cruise control systems on 1982-83 Impalas and Caprices equipped with the THM 700-R4 transmission may experience a loss of speed from the set point on long hills. This condition may be due to certain vacuum conditions and may not allow a 4-3 downshift in the transmission.

Service kit (P/N 14080393) has been released to correct this condition. The following instructions are included in the kit and should be used to correct the vehicle (reference Figure 1 for a diagram of the revised system).

1. Cut hose between air management valve and air cleaner 2.5 inches from valve and remove 1 inch of hose from remainder and discard. Insert back pressure valve (P/N 14080391), poppet opening toward air cleaner, and clamp both ends of 2.5 inch hose with hose clamps (P/N 549589). See Figure 2.

2. Remove 3/4 inch of hose from between air management valve and air pump, discard. Insert tee (P/N 14080392) and clamp both ends with hose clamps (P/N 549589). Insert 2 inches 1/2 ID hose on third leg of tee. Insert aspirator (P/N 25031503) on other end of 2 inch hose. Clamp both ends of 2 inch hose with hose clamp (P/N 477402). See Figure 2.

3. Install new servo (P/N 25031843) in existing servo bracket with existing screws.

4. Cut vacuum hose from manifold to transducer 12 inches back from transducer. Insert check valve (P/N 14047619), 3 inches of 1/4 inch ID hose not included, and check valve (P/N 10023289) as shown in View A on Figure 3.

5. Insert other outlet of dual outlet side of P/N 10023289 into cut hose running to transducer. See Figure 3.

6. Add approximately 4 feet of 1/4 ID hose (not included)from aspirator (P/N 25031503) to single outlet side of P/N 10023289. See Figure 3.

7. Route above hose per drawing and band with straps (P/N 11501907) as shown.

PARTS LIST OF KIT (P/N 14080393)

Part Number Name Similar To Quantity ----------- ---- ---------- --------- 14080391 (New) Back Pressure Industrial 1 Valve Strainer Co. #11330 549589 Hose Clamp 4

477402 Hose Clamp 2

14080392 (New) Tee Baylock #112795 1

25031503 Aspirator 1

10023289 Check Valve 1

14047619 Check Valve 1

11501907 Strap - Plastic Adjustable Tie 2

25031843 Servo 1

Tube*

Hose**

*Tube 5.16 - 5.96 ID, 10.06 - 10.82 OD (GM 6148-M (UMC 74381)). Approximately 4 feet not included.

**Hose 1/2 ID GM 6165M not included.

Labor Operation Number: T-1103

Labor Time: .4 hours

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.