Leaking fluid under rear right side of truck

yukon2000 · January 6, 2006

Gm Tech,

I have a 2000 GMC Yukon SLT 1/2 ton 5.3 litre. I found a small puddle of clear oily fluid under my truck on a couple occasions on my garage floor inside the rear right tire. I have noticed when shutting off the truck after driving there is a odor (as something is burning) coming from the truck from not under the hood. Is this fluid leaking onto something hot to create this odor? Could the fluid be from a strut, break lines? What fluids run thru/by this location of the truck? I would appreciate your feedback.

Thanks!

GM-Tech · January 6, 2006

What does it feel like? Is it oil? If it is an oil like substance and you can mix in a little water with no problem, it's brake fluid. If it remains separate, it's oil.

On the other hand, could it be condensation coming out of the muffler? When started cold, there's quite a bit of condensation build up in the muffler and there's a little drain hole in the bottom rear of the muffler. This can leave quite a puddle, but there should be no doubt that it's water.

Haven't seen a shock leak so much as to leave a puddle.

yukon2000 · January 6, 2006

What does it feel like? Is it oil? If it is an oil like substance and you can mix in a little water with no problem, it's brake fluid. If it remains separate, it's oil.

On the other hand, could it be condensation coming out of the muffler? When started cold, there's quite a bit of condensation build up in the muffler and there's a little drain hole in the bottom rear of the muffler. This can leave quite a puddle, but there should be no doubt that it's water.

Haven't seen a shock leak so much as to leave a puddle.

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It is a oily substance with a rich smell. I wiped it up with a cloth so I don't know for sure if you could mix in water. Twice now I found a small puddle underneath the rear axle on my garage floor next to the right tire. Are there brakes lines in this area? What fluid would be located in this area? The front axle seal was replaced a couple years ago because it was leaking. Could my rear axle seal be leaking in this area? I doubt it would be condensation from the muffler because that would be more of a water substance not a oil-like feel, also because of the location I'm finding this puddle-it's not under the tail pipe. The best way to describe the odor/smell after turning off the truck is like burnt rubber. Usually when it is wet out. Is this fluid leaking onto something hot to create a burning smell/odor? I need new brake pads and rotors so I'm wondering if this fluid or smell is related to each other. Look forward to hearing back from you.

Thanks again.....

yukon2000 · January 7, 2006

What does it feel like? Is it oil? If it is an oil like substance and you can mix in a little water with no problem, it's brake fluid. If it remains separate, it's oil.

On the other hand, could it be condensation coming out of the muffler? When started cold, there's quite a bit of condensation build up in the muffler and there's a little drain hole in the bottom rear of the muffler. This can leave quite a puddle, but there should be no doubt that it's water.

Haven't seen a shock leak so much as to leave a puddle.

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It is a oily substance with a rich smell. I wiped it up with a cloth so I don't know for sure if you could mix in water. Twice now I found a small puddle underneath the rear axle on my garage floor next to the right tire. Are there brakes lines in this area? What fluid would be located in this area? The front axle seal was replaced a couple years ago because it was leaking. Could my rear axle seal be leaking in this area? I doubt it would be condensation from the muffler because that would be more of a water substance not a oil-like feel, also because of the location I'm finding this puddle-it's not under the tail pipe. The best way to describe the odor/smell after turning off the truck is like burnt rubber. Usually when it is wet out. Is this fluid leaking onto something hot to create a burning smell/odor? I need new brake pads and rotors so I'm wondering if this fluid or smell is related to each other. Look forward to hearing back from you.

Thanks again.....

asilverblazer · January 7, 2006

There is brake fluid in the area, brake fluid is at every wheel, and could leak out, I would start where the brake line comes down from the frame and follow it to the wheel looking for leaks. An axel seal could go bad as well allowing axel lubricant out to the wheels. Either fluid if contacting the hot brake rotor will result in a burning fluid smell. Not sure which would be the more likely culprit. Maybe pulling the wheel and tire and possibly even rear rotor would provide more insight where the fluid is coming from.

GM-Tech · January 7, 2006

Axle fluid has a very strong odor. If you had enough brake fluid leaking to leave a puddle, you would have NO brakes. The pedal would certainly go right to the floor.

I don't think there's any mystery here. Get the truck on a lift or jack stand, pull the wheel and see where it's leaking from and quit guessin'. If there's that much fluid, it should be easy to spot. There's only a couple possibilities.

yukon2000 · January 8, 2006

Axle fluid has a very strong odor. If you had enough brake fluid leaking to leave a puddle, you would have NO brakes. The pedal would certainly go right to the floor.

I don't think there's any mystery here. Get the truck on a lift or jack stand, pull the wheel and see where it's leaking from and quit guessin'. If there's that much fluid, it should be easy to spot. There's only a couple possibilities.

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Thanks for all your help. I appreciate your insight......