Locked brakes after a cruise.... Then not..

[rakort]

I'm in the camp of a master cylinder issue. Rod too long won;t let the piston all the way back and release residual pressure in the system from heat and expansion. As I recall it's kind of like a clutch, and ya need a little free pedal to ensure the piston comes all the way back.

If the rods not allowing the piston to return to the full rest position, fluid pressure will eventually build up and the brake will start dragging. Let it sit a bit and pressure will bleed off again, until the next ride. Even the smallest degree of excess rod length will cause this issue. Easy to check, and even easier to fix.

 

[moparwacko]

My money's on the rubber hoses, seen it several times over the years. Hoses don't have to be bulged- they are degrading internally creating a flap like a valve. Replace all the hoses, flush the system VERY VERY well, refill with DOT4, and drive it. Even the MC is a relatively cheap replacement as are all the wheel cylinders. Unfortunately our cars sit for long periods of time and DOT 3 will absorb moisture then bad things happen.

 

[stuka1166]

My Road Runner had the same issue...I disabled the parking brake and it's good to go

 

[rakort]

My Road Runner had the same issue...I disabled the parking brake and it's good to go

hrmm, that doesn't sound like a "sound" solution.

 

[MikeyT]

Maybe found the culprit, took off the drum and the adjuster was way out of whack, I adjusted a back some and actually even adjust to the one on the passenger side, took it for a drive no heat seems to be doing good. * crosses fingers*

Mikey

 

[stuka1166]

hrmm, that doesn't sound like a "sound" solution.

Agreed...It was just a band aid until I get someone more "capable" to look at it.

 

[MikeyT]

Thanks everyone for your help

Mike

 

[Propwash]

Mikey,

I'd reset the initial shoe adjustment per the FSM and go from there. Always start with the easy stuff first. Like mentioned, any excessive heat will lock up a brake. A warped drum will also cause heat/lockup.


Sorry Mikey.....didn't catch your update. Hope it cured it for you!

 

[Lets Roll]

I had this happen years ago in a 72 Dart, It was a bad brake hose. It drove me nuts because sometimes it would happen and sometimes I'd drive all day and nothing. I replaced all the flexible hoses and it went away. Of course I replaced a whole bunch of stuff before i figured this out.

 

[snakeoil24]

Heat from headers next to distribution block! insulate and then see what happens. Also heat from headers rising up to master cylinder, chrysler used to supply a heat shield that was bolted to bottom of master cylinder just for this reason. If this is not it then try covering line going to back of car near headers. If this is not the answer then relief valve in distribution block might be Fcked!

 

[acme rat killer]

Sounds like you found it. years ago my dad replaced almost every part of a front disc system, Bad hose, you can push the fluid through a bad hose Mechanical advantage, but it returns very slow. To check this apply brakes and release, turn tire, if it wont move, open bleeder, it will be under pressure if the hose is bad. and the tire will turn, if it dosent the wheel cyl. or caliper is bad.