Transmission cooler has a hole

Hi,

If you lost a lot, two quarts may not have been enough. If it is low enough, it can cause lower pressure in the transmission and allow the clutch packs to chatter. That will cause them to eventually fail.

Did you check the level after you added the two quarts? If you haven't, start with that. When checking, the engine should be at operating temp, the engine running in park, and on a level surface. Take a look at pic 1 below. It explains things to look for.

The cooler needs replaced. There is quite a bit of pressure that is in the system. Most sealers won't work and if they do, it's not for long.

There are two different transmissions that could have been used. I will provide the directions for the removal and replacement of the cooler for both.

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2000 Chevy Truck K 1500 Truck 4WD V8-5.3L VIN T
Transmission Oil Cooler Replacement
Vehicle Transmission and Drivetrain Automatic Transmission/Transaxle Transmission Cooler Service and Repair Procedures 4L80-E Automatic Transmission Transmission Oil Cooler Replacement
TRANSMISSION OIL COOLER REPLACEMENT
Removal Procedure

pic 2

1. Remove the two bolts securing the auxiliary oil cooler bracket to the radiator support.
2. Remove the auxiliary oil cooler from the radiator support.

Installation Procedure

Notice: Refer to Fastener Notice in Cations and Notices

pic 3

1. Install the two bolts securing the oil cooler to the radiator support.
Tighten the bolts to 12 Nm (9 ft. Lbs.).
2. Ensure the guide pin bolt is positioned into the support hole.

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2000 Chevy Truck K 1500 Truck 4WD V8-5.3L VIN T
Transmission Oil Cooler Replacement
Vehicle Transmission and Drivetrain Automatic Transmission/Transaxle Transmission Cooler Service and Repair Procedures 4L60-E Automatic Transmission Transmission Oil Cooler Replacement
TRANSMISSION OIL COOLER REPLACEMENT
Removal Procedure

pic 4

1. Refer to grille assembly. Refer to Grille Replacement (Chevy) or Grille Replacement (GMC) in Body and Frame.
2. Remove the two nuts securing the two cooler lines to the oil cooler.
3. For vehicles not equipped with the 4.3L- engine, remove the four bolts securing the auxiliary oil cooler to the radiator support.

Pic 5

4. For vehicles equipped with the 4.3LL engine, remove the four bolts securing the auxiliary oil cooler to the radiator support.

Installation Procedure

Notice: Refer to Fastener Notice in Service Precautions.

Pic 6

1. For vehicles not equipped with the 4.3L engine, install the four bolts securing the oil cooler to the radiator support.
Tighten the bolts to 10 Nm (89 inch lbs.).

Pic 7

2. For vehicles equipped with the 4.3LL engine, install the four bolts securing the oil cooler to the radiator support.
Tighten the bolts to 10 Nm (89 inch lbs.).
3. Reinstall the grille assembly. Refer to Grille Replacement (Chevy) or Grille Replacement (GMC) in Body and Accessories.

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Let me know if this helps or if you have other questions.

Take care,
Joe

"Going easy" isn't the answer. Automatic transmissions have multiple drums that each have a stack of alternating steel and fiber clutch plates. Pressurized fluid is used to put pressure on them so they grab and stick together to apply. When the fluid level gets low enough, the pump sucks up air which can be compressed. As such, the required pressure can't build up, and with any torque, those plates will slip. That wears the fiber plates down very quickly. Normally the only wear that takes place is during the very short time periods during up and down-shifts when those clutch packs are expected to engage gradually for comfort.

Driving a mile with slipping clutch packs develops more wear than probably 200,000 miles of normal driving. I am the world's leader at dragging the last ounce of life out of something before I discard it, but this is one time when you're saving pennies and it's going to cost you lots of dollars later. Replace the cooler, and any lines that are rusty. The hit to your wallet will be minimal compared to walking home, and then still having to buy the cooler and have the transmission rebuilt.

Be aware that GM transmissions develop more pressure in their cooling systems than some other manufacturers. JB Weld might do the job, but for other leaks, such as when my mother ran over a large chunk of steel in the road and punched a hole in the side of the gas tank, I made a "temporary" repair with Chrysler's gray RTV Gasket Sealer. That repair lasted over 28 years until the tank rusted out, but there was no pressure to speak of that it had to hold in. Chrysler has a black RTV Sealant that stays more flexible and rubbery, but it absolutely will not bond and seal through any light film of oil or transmission fluid. When we used it on transmission pans, the sealing surfaces had to be perfectly clean and dry. Chrysler's gray sealant cures a little harder and is harder to remove later, but it will seal through a film of oil, although you still want to try to avoid that. I'm sure GM and aftermarket suppliers have similar sealant products. I just happen to be familiar with Chrysler's and I know they work well. I wouldn't trust them to hold up to the ten or 15 pounds of pressure on a transmission cooler though. You'd have to build it up really thick to prevent it from being pushed off by the fluid pressure.