that tubes ID is too large for your trx350 ranchers bleeder nipple, they are roughly about 1/8 ID, you should be able to push 1/8 ID down over the bleeder nipple. I never use anything like this, I always just put a drain pan under the brake area, and bleed them like that.
Would a 20 oz. bottle be too large? Forgive my lack of knowledge, but with only using a pan, wouldn't air get in the lines?
don't know about the bottle thing ?. using a pan would not let air get in, if your holding the brake lever, and tighten the bleeder nipple before you release the lever ?!..lol. you ARE bleeding brakes on an atv, correct ??. if so ?, then the pan has nothing to do with air getting into the system. I've done it this way for 20 years, never, not once have I had trouble bleeding brakes, a pan, 10mm or 8mm box wrench, bottle of brake fluid, pair of vise grips, walla, brakes done !. oh, NEVER LET THE MASTER CYLINDER GO EMPTY !!!, this is how you get air back in the system ?, or you leave the bleeder nipple open, and release the brake lever ?..lol.