Drum Brakes Failure

[erik70rt]

Yesterday on my way home from a show, my brakes started failing.  They were fine when I left the show, but by the time I got home I had to put the pedal to the floor to even get them to slightly engage.  I popped open the master cylinder and checked the fluid, which was fine.  I looked around for leaks and didn't see any.  I thought maybe it was brake fade from driving on the highway for a while.  Never had the problem before when diving n the highway though.  I haven't popped the drums off yet to look for anything out of the ordinary.  I did have the front drums off not too long ago to change the ball joints, so I did a visual inspection and all looked good.  Manual brakes.

I plan on switching to front discs as I rebuild the car.  So until then, I still need the drums to work. 

Thoughts? 

[ec_co]

check the back side of the drums to see if the wheel cylinders started spewing. I assume no puddles under it to indicate a blown line

[tman]

Sounds like your master cylinder is failing.  Its an internal leak within MC, seals are wearing out.  You can rebuild the MC or replace it. Confirm none of the brake cylinders are not leaking first.  Another issue can be brake hoses swelling when you apply the brakes.  But the way you are describing a 'sudden' issue is the MC is the problem particularly if its full of fluid.

[Burdar]

Yep, sounds like the master is on its way out.  What happens when you pump the brakes?  Do you get a good pedal if you pump the brakes multiple times or does the pedal stay low?

[erik70rt]

Yep, sounds like the master is on its way out.  What happens when you pump the brakes?  Do you get a good pedal if you pump the brakes multiple times or does the pedal stay low?

Stays low.  No build up of pressure.

Yes, no puddles or drips that I can see.

[Rich G.]

Yes if the are no leaks and the MC is full , brakes adjusted properly it's the master cylinder like everyone sad. Make sure you bench bleed the new one first before you put it on.