6L50 Pump 2006, new and ready to install. Fits the 6L50. Ships fast from the USA.
If your Cadillac CTS or STS, V6 Camaro or other 6L50-equipped car is slow to pick up Drive after a cold start, flares between gears once the fluid is hot, or hums with a tone that rises with engine speed in Park, the wear is often inside the front pump. This listing is a new GFX pump repair kit for the 2006-and-up GM 6L family: a 13-vane rotor, the matching pump slide, a full set of vanes, the vane guide rings and the pump O-rings. You reuse your own pump body, cover and stator shaft. It is a rebuild kit for a pump you are opening up on the bench, not a bolt-in pump assembly.
The industry number is K135927A. The same kit is catalogued for the 6L45, 6L50, 6L80 and 6L90, because those four units share the pump rotating group even though their valve bodies and clutch packs differ.
The 6L50 pump is a variable-displacement vane design. The converter hub spins the rotor, centrifugal force and the guide rings push the 13 vanes out against the inside of the slide, and the slide swings on a spring-loaded pivot pin to change how much oil each revolution moves. At idle the slide sits at full output so the clutches fill quickly; at cruise, pressure from the regulator swings it back so the pump stops wasting horsepower. Every clutch apply in the six-speed, the converter clutch and the cooler and lube circuits run off that flow. When the vane tips, rotor slots or slide bore wear, oil slips past the vanes, output drops at low RPM and the pressure control solenoid has nothing extra to work with.
Sonnax notes that the slide pivot pin in this family wears under normal use and causes erratic line pressure, pump leaks and pump noise, so a worn pump rarely fails in just one place.
Start with fluid level and condition using the correct check procedure, then put a gauge on line pressure in Park, Drive and Reverse at idle and at a raised RPM. Pressure that comes up with RPM but is weak at idle points at the pump. Pressure that stays flat no matter what you do points more at the pressure control solenoid or valve body. Our 6L pump failure symptoms guide walks through the same tests, and the 6L45 limp mode guide covers the electrical faults that can look like a pump problem. Once the pump is out, look for scoring in the pump pocket. Deep scoring means the body needs replacing, not just a rotor kit.
This kit is listed for GM 6L50 transmissions from 2006 on, and the same parts fit the 6L45, 6L80 and 6L90. Before ordering, measure the thickness of your old rotor and slide and count the vanes. This kit is .708 in with 13 vanes, and it only works if that matches what you pull out. BMW GA6L45R pumps differ in some details from GM pumps, so BMW owners should check their parts against the photo. If you are not sure, send us the year and VIN before you order. You can see every 6L part we stock on the 6L50 parts page.
Clean the pump body and check the pocket and cover faces for scoring and flatness. Fit the guide rings, set the rotor in the slide and install the vanes so they slide freely in their slots. Replace the pivot pin and spring if they are worn, then lube everything with clean Dexron VI before closing the pump. Use the new O-rings, a new front seal and a new pump bushing if the converter hub shows wear. Check the hub for grooves before reinstalling the converter. Torque the pump bolts in a crisscross pattern and prime the pump before the first start. If the transmission is coming apart anyway, the 6L50 master rebuild kit covers the frictions, steels and seals. If the stator shaft bushings or ring lands are worn, the 6L45/6L50 pump stator assembly replaces that half of the pump. Refill with Dexron VI to the hot level and check it the way our 6L50 fluid guide describes.
| Fits | 6L50 2006 |
| Part type | Pump |
| Condition | New |
| Brand | GM |
| Reference | K135927A |
| 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 repair kit for the parts inside the pump: the 13-vane rotor, slide, vanes, guide rings and O-rings. Your own pump body, cover and stator shaft are reused. If the pump pocket is deeply scored or cracked, the pump body itself has to be replaced.
The kit is catalogued for the 6L45, 6L50, 6L80 and 6L90 from 2006 on. Measure your old rotor and slide first. This kit is .708 in thick with 13 vanes, and those must match what you remove.
Replace the front seal, the pump O-rings (included), and the slide pivot pin and spring if they are worn. Replace the pump bushing if the converter hub has worn it. Inspect the converter hub for grooves too, since a rough hub will quickly ruin a new seal and bushing.
GM specifies Dexron VI. Pre-lube the vanes and rotor with it during assembly, and set the final level hot using the check plug procedure.
Only if the pump is the cause. Test line pressure first. Low pressure at idle that rises with RPM points to the pump. Flat or erratic pressure can be a pressure control solenoid or valve body problem, which a pump kit will not fix.
