Bleeding Trailer Brakes and Air Bubbles Won't Stop

Question:

I still have other problem to bleed the air out of brake line. I am using small clear flexible tube to connect to a zerk fitting and a bottle fill with brake fluid to bleed the air bubble out. But the air bubbles are there for ever i cant bleed them all out. They keep coming what ever or how long i try to pump the master cylinder. I kept filling up fluid and never get fluid low in the master cylinder reservoir . The air bubbles keep coming i think the master cylinder having some issues pumping the air inside the brake lines

asked by: Kevin

Expert Reply:

If the air bubbles aren't ever stopping that indicates that air is getting introduced into the brake lines. Most likely through a bad master cylinder but since we know yours is a new part # T1777401 that would make me think that most likely you are leaving the bleeder open before releasing the master cylinder which is basically allowing the lines to suck air back in.

Pressurize the system, open the valve, close the valve, release pressure.

expert reply by: Jameson C