I know nothing about your type saw, but was curious and found a video that might explain your problem. If I understood the portion of that video correctly, there may be two white washer like things on the mounting bolts that were supposed to be removed before ever using the saw that were presumably there for shipping protection. They would prevent the cover with spring from sliding all the way on and grabbing the clutch. Look here.

Thanks for the reply. I have seen this , it is not my problem. The brake appears to work , but doesn't close enough on the clutch to stop the saw chain. ( Actually years ago I did what this guy did which was force the cover off when the brake in on, what a pain, but easy fix)

“How husqvarna 435 chainsaw chain break stops the chain youtube”. Is the search I ran to see if one of the videos
will help you. Is it correct that the
break is not stopping the chain? Does the break’s handle appear to be making
proper contact with mechanics to engage the brake band on the hub to stop
it? If not I would say the mechanics is not assembled correct.

If so, I have seen mechanics that can be adjusted to keep the handle
from being too sensitive (possible to cancel the break or excess resistance). Please show a Picture if any ext. adjustments are related to the handle

Hopefully something in the videos will help, plus there seems to be more
videos related showing.

https://www.youtube.com/watch?v=usP5XaXO7-8

https://www.youtube.com/watch?v=gK7eKakMCz8

https://www.youtube.com/watch?v=9PIDvWmJEo4

Thank you for the reply and looking up the videos !!!! The break engages ( you hear and feel a significant pop ) and the mechanism appears to compress/release the spring and the band position ( if you look at the pictures moves) but the band doesn't tighten. My guess was that the band was broken , but if so there is no sign of it and it appears to move. Just this seems unexplainable. Maybe the band is worn IDK,,, Guess I could replace it. I have no other ideas.

Have you removed the band from
the cover and inspected the ends and related parts?

I doubt this is a problem
with your saw only. If no others report
this problem and fix, is there a Husky-Support # you can call? I hate to think its wear due to a break is
seldom used. This will be an interesting
find if it’s not a Quality Matter.

I assume that you can see how many degrees the brake lever rotates when you move that lever. Does the three sided engaging 'gear' appear to have rotated as far?

It has to be the band... I've ordered a new one and will replace it ( AGAIN) . I think there is a quality issue with it since this is the 2nd time in 5 years I've replaced it and I only use the saw in the fall. Unfortunately it's a pain to do as the spring is very loaded up. Husq has no direct support , only dealers . Thanks for all the advise and comments !!!

Well, the thing is that your pics show that your band appears to be fine. Sure, I guess that they could be oversized or perhaps you accidently got the wrong replacement originally. I have had to fool around with a band for a separate issue. It seems to me that the band is just not being tightened Enough. That is why I asked about the actual rotation of the 'gear'.

It appeared to be .. Took it apart last night , it's broken at the connection point which is out of view .... New one on the way .. Thanks for all the advice and comments !! Not sure why it would fail so frequently. Maybe I'll order 2 ;-)

Did the 1st fail
at that same exact location? Can you
share a picture of that point or a link with ref to the point? Good Luck Installing “The Monster”. I have only installed a small 14” Electric
Mac. Thanks!

No it failed at another location right where the band bends around the mechanism that is engages the brake ( so it was almost invisible unless that was taken out) . Swapped it out last night, sorry forgot to take a pict. That spring is evil to get into place, and I'm not a small guy.