I was taking my front driver side tire off the other day, and when I was under the car placing the jack, I noticed that the driver side frame rail (by the wheel) was wet and the paint is all eaten away. Sometimes I smell fuel if I have been driving the car for a while, could there be a puncture in a fuel line? On which side of the car does the fuel line run?

 

..dont know if fuel can eat away at paint...but brake fluid will do a nice job. Suggest
parking her after a long drive and sliding some cardboard under the affected rail and look for any wet-spots to find out of its oil, gas or brake fluid....maybe a combo of each. Oil has a way of seeping out from old seals and gaskets....my oil pan was seeping and it made a mess of the driver and passengers rails.

 

both the fuel and brake lines run down along the firewall on the driver side and hug the inside of the framerail, you could very well have a line that has rusted through. check underneath the small tabs that are bolted to the body that hold the lines in place, if there is a rusted out section itll likely be under one of those retainers

 

1st I changed your title to reflect your issue. :-)

Have you checked the brake fluid level?

What does the fluid smell like, gas has a very distinct odor!

 

Maybe your bleeder valve is opened just slightly.

 

My steering box was leaking and peed out it's contents all over the frame rail underneath it. I noticed that it had been eating the paint there when I was doing my engine swap a while back, new paint and a rack and pinion conversion is my solution for it.

 

I don't think its brake fluid, because the pedal pressure is still firm as its always been. I thought it was fuel because a few weeks back I had put ATF in the gas tank, and when i first noticed the leak, it was RED drops forming on the rail. When I try to smell the fluid on the frame rail, I can't smell anything when its on my fingers, so that made me think it might not be gas. Whats a low odor fluid (that could be red) that could be leaking there?

My clutch, brakes, and power steering do not show any signs of leaks. No abnormal sounds or feeling from them. (Ok my clutch master squeaks a little)

Thanks for the title change, mine wasn't very informative!

 

Are you sure it's paint that's coming off? Oil and/or fuel will soften the undercoating that Mazda sprays all over the underbody. Neither will remove the the oem base/primer/sealer paint coat. Brake fluid will, down to the bare metal.

 

+1 for brake fluid

 

Two questions:

A. Is the fluid leak/wet area from the wheel centerline forward or from the wheel centerline rearward?

B. If the fluid leak is forward of the wheel centerline it very well could be battery acid leaking down from the battery.

 

Absolutely confirm it is not brake fluid, because if it is, you have a serious safety issue:
1. Check the brake fluid level (not just the firmness of the pedal.)
2. Pump the heck out of the brakes, with engine on
3. Recheck brake fluid level (and see if spot of leaking fluid below car.)

if brake level has not moved, you have eliminated a brake leak.

 

So why did you put ATF in the gas tank again??

Anywho... Wipe it all clean and dry with some carb or brake parts cleaner. If it comes back then you have a problem. if it doesn't and your not experiencing any problems with your clutch or brakes or power steering etc... then your in the clear and you must've spilled something on accident.

 

I thought ATF was good at cleaning out seals/carbon in the engine?

 

ATF works for cleaning carbon, when poured down the carb. Not into the fuel tank. Always start with the least caustic/corrosive method, i.e., Seafoam in the fuel tank. I have no idea what ATF may or may not do to the fuel pump. Fill your tank up and dilute the ATF mix as much as possible, then drive around until it's gone.

Just taking a wild guess here, do you have power steering? Perhaps that's where the red fluid came from.

 

Well I only put a little ATF in, no more than a fourth of a quart. And I put that in with a fresh fill up, so I can't imagine it did any harm.

It's definitely not ATF that's leaking though. Fairly certain that it is indeed brake fluid so I am parking the car until I can fix it.

Not happy with the work the mechanic did on my car.

He replaced the front rotors and bearings. The bearings squeak and the brakes are obviously leaking (they were not before) and he claims to have fixed the six port, but after closer inspection it wasn't even hooked up.