the other day I was going downhill with a trailer with some weight on it. braking harder than usual my brakes gave for a split second and then came back. parking brake light came on. Now they are far more spongy than they used to be. I remember when I was drunk adding some lucas stop leak to the power steering, but like a dumbass startted to put some in the brake fluid resivoir. just a bit though. Would this cause a pressure differentail? it is way thicker than dot3 brake fluid. someone told me I may have to replace all braking system components because it may have detergents. I thought that stuff helped seals, not eats them. still spongy, but if I brake suddenly, I feel like it catches something and brakes normally, where if I ease into it they will spongy brake and almost go to the floor. Any ideas?

 

You boiled your fluid. Completely flush out the system with new fluid and you should be good to go.

 

^x2 or you popped the seal in the master cylinder for the rear brakes, that will make the pedal spongy too

 

Try flushing first. Lucas etc softens the rubber seals, it's a petroleum product. Brake fluid is something else.
A good flushing may get it out before it does much damage, - if it's only a little bit.
Else ALL the rubber parts will have to be replaced, caliper pistons, wheel cylinders, MC etc - $$$.

Do it ASAP!

 

I had the same thing happen to me, it ended up being the seal on the wheel cylinder. Just check the rear drums for leaks.

 

no leaks anywhere. it definately felt like something popped and it does feel like the front brakes are doing way more than the back. I will try the flush and go from there. hopefully its nothing past a master cylinder

 

got the brake fluid flushed about 3 weeks ago. Iv been driving it normally and had no issues. back to normal. thanks for the tip