Slow Leak Coming Out of Frame Rail

[audiquattrot]

Was it ever confirmed to be a fluid? How does it feel and smell? If nobody can confirm it's actually brake fluid then I wonder if it's just water? Condensation builds up in the frame, catches a lot of dirt/grease, then gathers and drips?

def smells and looks like brake fluid as it's yellowish/clear in color. I was hoping it was residual from months ago when my slave was gushing out and had to replace it, but ive cleaned underneath several times, and the fluid does appear to be fresh coming out of the rail.

[E30 Wagen]

Was it ever confirmed to be a fluid? How does it feel and smell? If nobody can confirm it's actually brake fluid then I wonder if it's just water? Condensation builds up in the frame, catches a lot of dirt/grease, then gathers and drips?

[audiquattrot]

bumping this thread up. I've been chasing this same issue for months. Bone dry behind the clutch master, slave cylinder recently replaced, bushings on the master cylinder holding the reservoir replaced, and all hard lines bone dry.

Only dripping out of that frame rail hole. Any other ideas on where it could be coming from?

[Undiluted]

Looking more like a brake fluid or a leak from inside of the firewall or the outside.

[Toon]

Put a paper towel under the brake booster and see if it gets wet.

This is a good idea!!

[Northern]

Is there a drain there that would lead to the frame rail hole where my leak is coming out of?

No, just if it runs down the firewall and onto the frame rail.

[twright]

Put a paper towel under the brake booster and see if it gets wet.

[AmosCake]

The only thing that is even remotely in that area is the brake/clutch fluid. I had a leak at the plastic elbow on the clutch master that would drip slowly and absorbed through the carpet before and eventually out of the frame rail before I found it. I did notice I was losing brake fluid but it was so slow I didn't think much of it. If it's not your clutch master, it could also be the brake master leaking into the booster or the lines, or the fitting to the clutch slave cylinder.

I have a feeling it’s a fluid leak in the booster since that goes through the firewall but my brakes don’t feel spongy at all

[AmosCake]

Could be between the firewall and the thick insulation mat on the engine bay side of the firewall if your car still has that.

Is there a drain there that would lead to the frame rail hole where my leak is coming out of?

[reelizmpro]

The only thing that is even remotely in that area is the brake/clutch fluid. I had a leak at the plastic elbow on the clutch master that would drip slowly and absorbed through the carpet before and eventually out of the frame rail before I found it. I did notice I was losing brake fluid but it was so slow I didn't think much of it. If it's not your clutch master, it could also be the brake master leaking into the booster or the lines, or the fitting to the clutch slave cylinder.

[Northern]

Could be between the firewall and the thick insulation mat on the engine bay side of the firewall if your car still has that.

[AmosCake]

just based off how bad the paint looks around it, I imagine it's brake fluid.

Could be a leak from the brake or clutch master cyls, either dripping down the inside of the firewall or the outside.

Question, can there be fluid leaking from between the inside and outside firewall? I removed the carpet and its all dry

[AmosCake]

it could be coming from anywhere and following the rail down to the lowest point. check the brake lines including the hard lines along the rail. sometimes a rubber line will sweat before it gives out completely, they'll do it for quite some time. you want to check the hard lines to eliminate the possibility of corrosion / rust damage.

Thats what I figured but the it’s not coming from either side If that makes sense. Like it’s not wet before or after that hole. The hard lines are also on right side of the rail. The leak is coming straight form that hole.

[82eye]

it could be coming from anywhere and following the rail down to the lowest point. check the brake lines including the hard lines along the rail. sometimes a rubber line will sweat before it gives out completely, they'll do it for quite some time. you want to check the hard lines to eliminate the possibility of corrosion / rust damage.

[AmosCake]

just based off how bad the paint looks around it, I imagine it's brake fluid.

Could be a leak from the brake or clutch master cyls, either dripping down the inside of the firewall or the outside.

I wish it were that simple. I checked the master and its dry as an old lady's cooch.