Stihl 026 brake problem

[GTF]

The brake band on my Stihl 026 slipped off the drum when activated and engaged the chain. Anyone know what causes this? It doesn't look like anything is broken. I have purchased a new brake band but it does the same thing and will be damaged if I use the saw without fixing the cause of the problem.

 

[highsiera]

have had the same problem in the past, is the sprocket/ drum new or older? Is it worn? how old is the needle cage?

 

[GTF]

You are correct. I didn't think that the drum was that worn but I replaced the sprocket/drum and it works like a charm. So the worn drum was the issue.

 

[Lakeside53]

Two reasons:
-The drums get flared from use, so when you activate the brake it moves to the outside;
- the small landing zones cast into the body get worn or eroded/corroded way. The plastic insert then takes the brunt of the brake band moving.

Can't do much about the body nubs, but you can replace the plastic insert for a few $. Consider replacing BOTH the brake drum and band when you have this problem - often the band is worn and rounded on the edges.

 

[GTF]

Two reasons:
-The drums get flared from use, so when you activate the brake it moves to the outside;
- the small landing zones cast into the body get worn or eroded/corroded way. The plastic insert then takes the brunt of the brake band moving.

Can't do much about the body nubs, but you can replace the plastic insert for a few $. Consider replacing BOTH the brake drum and band when you have this problem - often the band is worn and rounded on the edges.

These wear patterns were evident when I looked at the old and new bands/drums side by side.