Suburban Fluid Change: How Much?

Changing the transmission fluid and filter in your 1999 Chevrolet Suburban is a straightforward process, but it's important to know how much fluid to use. The transmission in your Suburban likely holds between 5 and 7 quarts of fluid. When changing the fluid, it's recommended to start by adding 4 quarts, then letting the vehicle idle in park and putting it through all the gears. Check the fluid level when the engine is warm and running, and add more fluid as needed. Test drive the vehicle and re-check the fluid level to ensure it's at the correct level. It's also important to note that simply draining the fluid will only remove about half of the total fluid in the transmission, so it may be necessary to repeat the process or find a way to completely drain the fluid if you want to replace it all. Additionally, make sure to use the correct type of transmission fluid for your vehicle, such as Dexron III or Dexron VI.

The transmission fluid and filter change process

Step 1:

Start your car and let it idle for a few minutes to get the fluid to operating temperature. Then, turn off the ignition and raise the vehicle securely. Place a tarp, cardboard, or newspaper under the transmission pan to catch the fluid.

Step 2:

Remove the bolts from one side of the transmission pan, being cautious of hot parts and fluid. Gradually loosen the bolts on the other side, allowing the pan to tilt and begin to drain. Once all bolts are removed, lower the pan and empty the remaining fluid into the catch pan.

Step 3:

Use a screwdriver to gently break the gasket seal if necessary. Clean the gasket surfaces on the pan and the transmission housing. Inspect the pan for metal shavings or other signs of damage, then clean it with solvent.

Step 4:

Remove the old transmission filter and O-ring, being careful as the filter contains fluid.

Step 5:

Install the new transmission filter, ensuring the O-ring seats correctly in the orifice.

Step 6:

Attach the new gasket to the pan with oil-soluble grease, not gasket sealer or adhesive.

Step 7:

Refer to your service manual to determine if thread sealer is needed on the transmission pan bolts. Screw in all fasteners finger-tight, then torque the pan bolts to spec in a spiral pattern, starting at the center. Maximum torque is typically around 12 pounds per foot.

Step 8:

Lower the vehicle and fill the transmission with the recommended amount of fluid.

Step 9:

Start the vehicle and warm it up, then shut it off and check for leaks. If there are no leaks, run the vehicle up to operating temperature, cycle through all gears, return to park, and check the dipstick while the engine idles.

Safety:

Always wear appropriate personal protective equipment when working on vehicles, including safety gloves, goggles, helmets, and shoes.

The amount of fluid required

It is important to note that when performing a transmission fluid change, you may not be able to drain all the old fluid. A transmission fluid and filter change typically involves dropping the transmission pan and replacing the filter, which only allows for the replacement of about half of the total fluid in the system.

For a more comprehensive fluid change, some people recommend performing a transmission flush, which involves disconnecting the transmission cooler lines and circulating new fluid through the system. This method allows for a more complete exchange of the fluid but can be more complex and time-consuming.

Additionally, it is recommended to use Dexron VI transmission fluid for your 1999 Suburban, as it is superior to the older Dexron III specification and is backwards compatible.

The type of fluid to use

The type of fluid you should use depends on the type of transmission your 1999 Suburban has.

If your vehicle has a 4L60-E transmission, you should use Dexron VI Automatic Transmission Fluid. The initial fill for this transmission is 5 quarts, and the total fill is 11.3 quarts.

If your vehicle has a 4L80-E transmission, you should also use Dexron VI Automatic Transmission Fluid. The initial fill for this transmission is 7.8 quarts, and the total fill is 13.6 quarts.

If your vehicle has a 4-wheel drive transfer case, you will need to use Auto-trak II fluid, which is available at GM dealers. This fluid is required for GM automatic 4-wheel-drive vehicles with transfer cases. It is also recommended to use Auto-trak II fluid if your vehicle has a "Smart Trac" transfer case.

The transmission fluid drain plug

Locating the Drain Plug

The first step in the process is to locate the transmission drain plug. Its position varies depending on the type of transmission in your vehicle. If you own a manual transmission, you will typically find a large drain plug at the bottom of the transmission housing. On the other hand, automatic transmissions may have a drain plug either on the housing or the transmission pan, or the pan might need to be removed entirely.

Draining the Fluid

Once you've located the drain plug, place a fluid catch pan underneath it to collect the drained fluid. Using a ratchet and the appropriate socket, remove the drain plug or transmission pan. Allow the fluid to drain completely, or until it slows to a trickle. If you're removing the transmission pan, ensure you let the fluid drain before taking out the pan completely, as more fluid will continue to drain once the pan is removed.

Transmission Filter Removal

Some vehicles have a transmission filter that needs to be replaced. This filter may be internally or externally mounted. If your vehicle has an external filter, it is typically a spin-on filter, similar to an engine oil filter. For internally mounted filters, you may find a bolt holding the filter in place. Remove any bolts and then pull out the filter. Removing the filter will result in more fluid draining, so keep the catch pan in position.

Reinstalling the Drain Plug

After draining the fluid and addressing the filter, it's time to reinstall the drain plug. If you removed the transmission pan, clean it with a lint-free rag. Inspect the drained fluid and the pan for any metal debris or other abnormalities, as these could indicate potential transmission issues. Reinstall the transmission filter (if applicable) and the transmission pan, using a new gasket from a transmission filter kit. Torque the drain plug and pan to the manufacturer's specifications.

Adding New Transmission Fluid

Now it's time to add fresh transmission fluid. Locate the transmission filler plug, which is typically found on the transmission housing, about halfway up. Remove the filler plug using the ratchet and appropriate socket. Add the manufacturer's recommended fluid through the fill hole, using a fluid pump. Most manufacturers recommend adding fluid until it begins to come out, indicating that the transmission is full. Follow the manufacturer's filling capacity guidelines to avoid overfilling. Finally, reinstall the filler plug and torque it to the specified tightness.

Additional Tips

• Only use the manufacturer's recommended transmission fluid. Using the wrong fluid can lead to serious issues.
• Some transmissions are sealed and cannot be serviced, while others require a manufacturer-specific flush machine. Always check your vehicle's specifications before attempting any maintenance.
• If you haven't serviced your transmission in a long time, consider having it checked by a certified mechanic, as servicing very old fluid can sometimes cause internal problems.

The transmission fluid dipstick

To check the transmission fluid, first warm up the engine and leave the car idling in park on a level surface. Pull out the dipstick, wipe it clean, replace it slowly, then pull it back out. Check the fluid level against the "full" and "low" or "fill" marks on the dipstick.

Lay the dipstick on a white surface to analyse the colour of the fluid. Healthy transmission fluid should be reddish-pink. Fluid that is due for a replacement will be brownish-red, while dark brown or black fluid could indicate possible damage to the transmission's internal components.

If the fluid level is low, this could indicate a leak in the system. Filling up the transmission and checking it daily can help assess the severity of the leak.

If you notice any issues with the transmission fluid, it is recommended to contact a mechanic as soon as possible.

Frequently asked questions