Longest drive to date - brake issue.

[Conn47D24]

Took about a 10 mile run today.  Excellent Temp and oil pressure.  Smooth running.

 

I was feeling pretty good.  Then I heard a regular clicking noise, then brake pedal go very high and tight, then felt lots if heat below my feet.

 

Pulled over, didn't see anything.  Got home and front driver side hub cab, rim, and drum were VERY hot. 

 

Jacked it up and couldn't spin the tire by hand.

Removed tire and the hub bearing cup was pushed out almost all the way. 

 

Cooling overnight,  I'll adjust and pull the drum.

 

Hope I didn't any damage . Got lucky.

 

 

[TodFitch]

The pedal going very high and tight is a classic symptom of the relief port in the master cylinder either being clogged or that the piston cup is not clear of the port when the brake pedal is released.

 

I'd check the length of the push rod going into the master cylinder to assure there is a slight gap to the piston. The pedal should move about 1/2 to 1 inch before the rod contacts the cylinder. The other thing to check is that the relief port in the master is not clogged with some debris.

[Plymouthy Adams]

as an added note....ensure first the return of the piston to most rear position in the master before probing the relief port.....

[Conn47D24]

Once cooled off the drum turns easy by hand.

 

Step one today softly probed the relief port with a thin wire. 

 

Not a clog. MC piston was blocking.

I had to depress the pedal a bit and the wire slid in.

 

Soooooo

 

Next warming day I'll get under there and adjust the MC piston rod / pedal adjustments.

 

To confirm,  at the resting position, the primary rubber cup should be FORWARD of the relief hole ?

 

[Bryan G]

Unrelated, perhaps: I fought a problem with hot brakes. I'd set them just right, then the first time I pressed the pedal, too tight/wouldn't spin easily. Bad return springs at the drums, they'd lost too much tension.

[Sniper]

9 hours ago, Bryan G said:

Unrelated, perhaps: I fought a problem with hot brakes. I'd set them just right, then the first time I pressed the pedal, too tight/wouldn't spin easily. Bad return springs at the drums, they'd lost too much tension.

 

On a related note, make sure the surfaces of the backing plate that the side of the shoe rides on are clean and burr free.

[SteveR]

On 1/9/2023 at 10:44 PM, TodFitch said:

The pedal going very high and tight is a classic symptom of the relief port in the master cylinder either being clogged or that the piston cup is not clear of the port when the brake pedal is released.

I had this problem. The more I drove the car the higher the pedal was almost like having Power Brakes. If I left it a day it would be normal until I started using it again. I readjusted the master cylinder free play and the problem went away.

[greg g]

You need about an inch and a half of free play at the top of the pedal's travel.  In other words you must shorten the actuation rod to introduce the required slack.  Also assure your mc isn't over filled and the cap vent is clear.  This assumes your rubber brake lines are new and not rotted out.  Old lines can collapse internally allowing fluid to pass when the brakes are app.ied, but not allow return flow when released.

[Sniper]

26 minutes ago, greg g said:

Old lines can collapse internally allowing fluid to pass when the brakes are app.ied, but not allow return flow when released.

 

A simple test for that is when the issue occurs crack the bleeder, if brake fluid squirts out you might have this problem.