Brake cable housing will not stay in barrel adjuster on lever As you see the housing won’t stay in the barrel adjuster on the brake lever. When I brake it just comes out. I can pull it out with my hand anyone know how to fix?



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The brake cable housing is a slip fit into the brake lever barrel adjuster and cable guide bosses at various places on the frame (for the rear brake) or fork (for the front brake).

The housing is prevented from coming out of any of the mounting points by the cable having not enough slack for the housing to slide along it enough to pop out.

General process is to follow the housing from the brake lever to the caliper and you will probably find the housing has come out of a frame or fork mounting boss, or the cable is detached from the caliper, or the cable just has too much slack in it. I assume that is the front brake which goes directly to the front v-brake caliper. I'm guessing either the metal pipe 'noodle' that the cable runs through has come out of the caliper or the cable has come loose.

Park Tool has a good page on v-brake (or linear brake) service and adjustment that you can refer to. https://www.parktool.com/blog/repair-help/linear-pull-brake-service.

BTW, the cable looks like it is fraying - there's a strand visibly loose in your pictures. You should replace the cable. The front brake cable failing is obviously quite dangerous.