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#1088675 10/27/04 04:33 AM
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After installing new shoes, the rear drum brakes started making a crunching noise as I braked hard. This crunching goes: crunch crunch crunch as I brake harder and harder. It feels as if something is preventing me from making a smooth brake push. It's not a constant squeal so it sounds like crunching. This happens when both moving and while stopped.

Yes.. before you ask: I took off the drums and inspected this phenomenon. I looked for wear on the parts that would make this metal on metal sound.
It turns out the automatic adjuster has some wear coming from the Pac-Man-like part that you move to get the shoes to go inward to get the drum on. The part then moves as the pistons come out to move the adjuster or what not. I adjusted the thing and put some grease on where the shiny metal was at (the place that was grinding).

Everything was working fine and dandy until about 15 miles later. The same damn thing happens. I think it happens moreso when the brakes are warmed up... then gets worse the more I brake. Wtf is going on? I don't understand...
I have done some hard stops while going backwards to configure the automatic adjuster and the problem has stopped a few times but the problem persists.
Please help me here.


-1998.5 Contour SE V6 ATX. PM me to tell me of a welder that can craft me a modified Y pipe in the Los Angeles area! OR I may be willing to buy a 3 flange modified Y.
#1088676 10/27/04 08:10 PM
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Look at how the brake shoes are seating into the drum. You can see the wear pattern on the friction face of the shoes. You should see the wear on new shoes near the center of the shoe (lengthwise). If you see wear marks on the outer parts of the shoes (lengthwise), the shoes are not properly arced to the drums. Years ago there were machines that were used to grind the proper contour into the lining. I haven't seen one for many years.

If this is your problem, there is a way to correct the arc of the shoe. You will need to take the shoe back off. Hold the shoe in the brake drum to check how it fits. You should be able to slightly rock the shoe lengthwise in the drum. That is the center of the shoe should contact the drum while the ends will not unless the shoe is slightly rocked or rotated.

If you need to create some clearance on the ends, hold the shoe up lengthwise on a concrete floor and somewhat gently pound the upper part of the shoe with a hammer to cause the shoe to become a bit more arced. Be somewhat gentle because you can go too far and there is not way to go back. You don't need much. Roughly a 32" of rock when the shoe is held in the drum is more that adequate. Don't forget that once the shoe is fully seated into the drum after a few hundred miles of driving that the entire surface will seat evenly with no rocking. What you are after is to allow the shoes to seat properly from the center out. When they are grabbing on the exptreme edges they vibrate and make a lot of noise and may never properly seat.

I hope I was able to expain this clearly. It is easy to demonstrate, but a bit harder to put into words.


Jim Johnson 98 SVT 03 Escape Limited
#1088677 10/28/04 01:43 AM
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Originally posted by Big Jim:
Look at how the brake shoes are seating into the drum. You can see the wear pattern on the friction face of the shoes. You should see the wear on new shoes near the center of the shoe (lengthwise). If you see wear marks on the outer parts of the shoes (lengthwise), the shoes are not properly arced to the drums. Years ago there were machines that were used to grind the proper contour into the lining. I haven't seen one for many years.

If this is your problem, there is a way to correct the arc of the shoe. You will need to take the shoe back off. Hold the shoe in the brake drum to check how it fits. You should be able to slightly rock the shoe lengthwise in the drum. That is the center of the shoe should contact the drum while the ends will not unless the shoe is slightly rocked or rotated.

If you need to create some clearance on the ends, hold the shoe up lengthwise on a concrete floor and somewhat gently pound the upper part of the shoe with a hammer to cause the shoe to become a bit more arced. Be somewhat gentle because you can go too far and there is not way to go back. You don't need much. Roughly a 32" of rock when the shoe is held in the drum is more that adequate. Don't forget that once the shoe is fully seated into the drum after a few hundred miles of driving that the entire surface will seat evenly with no rocking. What you are after is to allow the shoes to seat properly from the center out. When they are grabbing on the exptreme edges they vibrate and make a lot of noise and may never properly seat.

I hope I was able to expain this clearly. It is easy to demonstrate, but a bit harder to put into words.




You explained it perfectly.
IIRC the shoes were wearing at about the center, towards the edge that gets pushed out. I'll check to make sure this weekend and will post the results.
It seems odd though this problem affects the automatic adjuster and in turn makes this crunching. But then again, you're the man.


-1998.5 Contour SE V6 ATX. PM me to tell me of a welder that can craft me a modified Y pipe in the Los Angeles area! OR I may be willing to buy a 3 flange modified Y.

Moderated by  Andy W._dup1 

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