Diagnosing A Driveway Fluid Stain

Yesterday I noticed a wet spot under my 1994 Mazda B2300 as I was backing out of the drive. Overnight it turned to a reddish brown, rust colored stain on the concrete.



I recently began getting a monotone squeek as I first back out of the drive (In Alabama). I’d like to catch any oncoming problems quick because I am planning on driving this truck to California in February.



Paul in Auburn, AL

Automatic transmission, or manual trans?

Is the maintenance up to date, as per the Mazda maintenance schedule?

Does it squeek just once or does it squeek repeatedly as you back out of the driveway?

What color was the wet spot when you first noticed it? If it was clear, check around the battery for wetness. Battery acid will turn a rusty color on concrete. If it was originally red, check underneath for evidence of transmission leak.

Also, the squeak could be a universal joint on it’s way out. A friend’s Suburban was making a similar sound, only in reverse, and the only thing near the source of the sound was the front universal joint at the transmission.

Is you coolant so old that it has lost its rust inhibator properties?

for you to diagose this (or at least get pointed in the right direction) you will need to get down and look, under, around the engine and beneath the truck.

try using a bright flashlight tonight and lay own in front of, or beside the truck and look for drips. be patient. it may take 10 or 15 minutes to see anything, or come back in an hour and look.

if you have a clean piece of cardboard, place it under the engine tonight to actually see where the drips are from. you can look at in the morning to see any fresh evidence. this way you will have a better idea where the drips are either dripping from or running down the driveway.

have you checked the fluids? brake, engine oil, antifreze, power steering? maybe keeping a tab on them will let you see if any are leaking.

you mention a noise. does this noise happen when you step on, or release the brake?

Cardboard under the truck at the suspected area . . . overnight . . . next day crawl under and look for another wet spot, then look up and trace it to the engine or transmission or rear end or radiator or whatever. I wouldn’t trust guessing what the fluid is after it has been on the ground for a few days, and the cardboard idea is so simple and easy there’s no reason not to try it. Rocketman

Sniff the leak and then start sniffing the auto fluids until you find it. Also check all the fluid levels.