200-4R Pump, used and ready to install. Fits the 200-4R. Ships fast from the USA.
A Monte Carlo SS, Grand National, Cutlass or Caprice with a 200-4R that engages late when hot, slips into third and fourth under throttle, or keeps burning 3-4 clutches is very often fighting a tired pump. This is a used, complete 200-4R pump assembly: body, cover and stator assembled together, cleaned, with every valve in the pump checked and moving freely. It is not a rebuilt pump, so it is the right buy for a builder who wants a clean original core to freshen with new rings, bushing and seal rather than paying for a reman.
The 200-4R uses a variable-displacement vane pump. The converter hub turns a rotor whose vanes ride against a pivoting slide, and the slide moves to raise or lower output as line pressure demands. The pump assembly also houses more than the pumping gear set: the pressure regulator valve, the reverse and TV boost valves and, on these non-PWM units, the converter clutch apply valve all live in bores in the pump body. That is why so many 200-4R pressure and lockup complaints trace back to this one part. Sonnax documents low or high line pressure from a worn slide pivot pin, and no lockup or lockup that drops out hot from a worn TCC apply valve bore.
The 200-4R is hydraulically controlled, so there are no trouble codes to read. A gauge is the diagnostic tool.
Set the TV cable first; a slack cable gives low line rise on its own. Then put a gauge on the line tap with the fluid fully hot and record pressure in every range at idle and with throttle applied. Low base pressure, weak Reverse boost or pressure that falls off as RPM climbs points at the pump and regulator circuit. Our 200-4R pump failure guide lays out the readings, and the delayed engagement guide covers the filter and seal faults to rule out first.
This pump is for the GM 200-4R used from 1981 to 1990 in rear-drive GM cars. The unit pictured carries casting number 8639082. The 200-4R changed over its run, including converter clutch control and pump valving, so compare the casting number, the stator shaft spline and the valve layout to your old pump, or send us your year, model and the transmission code before ordering. More parts for this unit are in the 200-4R collection, and a lower-cost option is the 200-4R pump listed for 1982-96.
If the clutch packs are already burned, the pump is only half the job. The 200-4R overhaul kit for 1981-90 supplies the seals and gaskets for a full rebuild, and the master rebuild kit adds frictions, steels and a band.
| Fits | 200-4R |
| Part type | Pump |
| Condition | Used |
| Brand | OEM |
| Reference | 8657690 |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is a complete used pump assembly that has been cleaned with the valves checked for free movement. Most builders fit new vane rings, a bushing, front seal and O-ring before installing it.
It is a 200-4R pump for 1981-1990 GM applications. The pump changed during the run, so compare the casting number 8639082 and the valving to your original, or send us your year and transmission code.
Yes. Worn regulator and boost valve bores and a worn slide pivot pin drop line pressure at wide-open throttle, which lets the 3-4 clutch slip and burn. Gauge test the pump before rebuilding the clutch pack.
On non-PWM 200-4R units the TCC apply valve sits in the pump body. Wear in that bore lets signal oil leak past, so lockup fails or drops out once the fluid thins.
Use a current GM-licensed Dexron fluid. Dexron VI is GM's service-fill specification that superseded the older Dexron grades.
