Brake fluid leak at the reservoir

Has anyone ever had the brake fluid leak out of the cap on the trailer tongue ?

And now the protective coating is delaminating around the cap area…

Why is this happening ?

How did you fix it ?

In order: No.
The caustic nature of the brake fluid is corrosive enough to cause the de-lamination.
So, why? : I’m thinking it’s ‘burping’….My guess is air in the line. Recent warm temps and or ‘use’ were enough to increase the line pressure and the only relief was to push pass the cap.
I’m thinking you’ll need to bleed the lines. Otherwise your brakes will either lock up going down the road, or the lid will pop and you’ll have no braking.
I just had to replace the the calipers and pads on my rig. I’m having a [censored] of a time trying to bleed the lines. Good luck with yours.

The cap seal was broke.. There is a seal in the cap. The new cap came and i would never had realized the difference unless I compared the two side by side…