Question about rear brakes.

[helpme]

I had the drum off looking for a suspected leak. So I pressed the brake pedal a few times and the piston, seal, and dust cover blew off the cylinder.
Now it seems to me I've done this before and all that happened was the shoes moved out 1/2 inch or so.
I checked and all the springs were in place before and after this happened.
So is this normal or do I have a problem somewhere?
Thanks.

 

[UrbanRedneckKid]

You pumped the pedal with the drum off...?!!!

 

[alwaysFlOoReD]

What happened is normal. Without the drum in place the hydraulic pressure shoots everything out like a water pistol. Put it back together and bleed. Don't worry, everyone does this unless taught not to. It's called learning by doing.

Richard

 

[RonD]

Yes, that would be normal, and something you shouldn't do, well more than once, lol.

The geometry of the slave's travel is based on the masters travel and the travel of the other 3 slaves.
Hydraulic pressure in the brake system will be equal at each slave, well a little more on the front slaves.
Since there was no back pressure from the drum on shoe contact the slave pistons on that wheel just kept expanding until piston came out.


Why "it didn't happen before" would be a puzzle, maybe a bad proportioning valve, gives front slaves more pressure than the rear or maybe shoes were jammed up and took the pressure.

 

[Tedybear]

Take Two Cans of Brake Cleaner and call us in the morning.

S-

 

[adsm08]

At least you didn't put the wheel on and try to drive off.

 

[Tedybear]

At least you didn't put the wheel on and try to drive off.

I'm not going to ask.

(what some customers do to their cars/trucks......)

S-

 

[helpme]

Thanks guys...

Just seems to me it didn't do this the first time.
Yes, I did put it all back together and bled that line.

 

[fixizin]

Take Two Cans of Brake Cleaner and call us in the morning. S-

Lulz... seriously though, it DOES take 2 big spray cans to do both rear drums + contents. But hey, long shelf life + BOGO sale = stock up. At least it's enviro-Algore-friendly.

 

[Tedybear]

Lulz... seriously though, it DOES take 2 big spray cans to do both rear drums + contents. But hey, long shelf life + BOGO sale = stock up. At least it's enviro-Algore-friendly.

Yep...2 cans is just the trick. We had the axle seal give out recently...and it spewed gear oil all over the rear brake on the right side. We use two cans just cleaning the snot out of everything. Seems to be the magic number for cleaner. (And BOGO sales ROCK!)

S-

 

[adsm08]

I'm not going to ask.

(what some customers do to their cars/trucks......)

S-

Nope, guy I used to work with. He was working on a Neon his first week at Monroe Muffler. Did his state inspection, checked the rear brakes, put the wheels back on and couldn't figure out why the brakes wouldn't get stiff.