New rear drums/shoes pulsate

[JoeR]

Just changed the rear drums and shoes on my 85 720. They had never been touched as far as I could tell. Once I got everything back together and adjusted, they still pulsate. I am wondering if I over-adjusted the shoes or if the drums need to be turned? Any input would be appreciated!

[dr.feltersnatch]

Did you check the front?

[banzai510(hainz)]

As the .Dr said ck the front also.

 

But on my Jeep Cherokee I had my brakes over heating with new drums. and its a auto adjust type system.But 2 set of drums(China). They made alot of parts in China for Cherokees.

to make this short, if the drums are made in China best to get them turned or keep the old drums and get them turned. Mine seemed to be warped. jack up jeep you can hear the drag at the same spot on rotation.. I nalso JB weld my adjusted so it wouldnt adjust and backed it off . so now I really got to crank the parking brake to get it to work. Someone told me the parking brake adjust the brakes(dont know how true)

 

 

when it comes to disk fronts try not to buy Chinese if there are other sources. But the rears for a Jeep where to to expensive to buy USA so I got the O rileys/autozone ect..... But best to get them turned.

[datzenmike]

Beginning of '82 the self adjusting rear brakes were added to the rear of the 720s. They automatically ratchet the star wheel when the brake shoe travel exceeds a certain distance. You do not have to do anything but keep the adjuster wheel lubed and free.

 

Probably the rotors on the front were hot... maybe a panic stop or steep down hill and not allowed to cool enough before the vehicle was parked. Pads that are new or have seen very little heat before will transfer a small footprint of the pad onto the rotor. When it turns, the pad grips it more than the rest of the rotor and over time can result in a high spot. New brake pads can be 'cured' by braking from highway speeds (but not stopped!!!) several times until you can smell them. Drive for another 15 min to let the rotors cool down before stopping for the first time.

[Ratwagon1600]

[JoeR]

I would have re-used the old drums except that they didn't have enough metal on them to be turned. I also checked the front rotors and pads and they are fine, they were replaced a few years ago. I know it's the rears because I feel the pulsation more through the seat and floor than through the pedal. I may have over ajusted the shoes. Should I back off the adjusters so there is no resistance or leave them with a little resistance?

[Ratwagon1600]

Something is most likely "out of round" i.e. the brake shoes and the drum arent forming a circle, think more like an egg shape.

 

Hard to diagnose via a keyboard though I would lean more towards backing off the adjustment a little bit.

 

You could also try scuffing the brake shoes with some 80 grit sandpaper and putting a slight chamfer on the leading and trailing edge of the shoe.

 

Clean the shoes after doing this with methalayed spirits (Ratsun brake cleaner) and a clean rag and try not to breathe the brake dust :)