Broken brake line on 1990 chevy 4x4 pickup (K1500) broke and drained master cylinder. Front disc brakes/rear drum brakes. ABS system. Once brake line fixed what is the bleeding procedure that must be followed.

It depends on the year, whether it has ABS and rear disc or rear drum brakes. If rear drum, then the front line goes to the bigger reservoir.

is ther a rear brake equaliser on the rear axle? this is usually spring operated that pulls up on the rear brake limiter depending on load in vehicle may be stuck in the vehicle loaded position when the vehicle isnt carrying much weight worth a look , just jack up rear end and look for spring device centre of rear axle attached to a device with the brake lines entering/exiting if there get vehicle as high as safe to do then put blocks under rear wheels then slowly lower jack and look to see if the spring device moves down with the vehicle if not this could be the problem as is exerting pressure to rear brakes so causing them to over heat keep me posted

try bleeding your ABS block first, if that doesn not work could need a master or proportioning vavle. Some scan tools are capable of bleeding the ABS system on some vehicles, and some you have to bleed manually.

Brother, it's just the fact that there is STILL air in your system. Just fill the master cylinder, open the left front line and let it run into a bottle to catch it for a bit until you know for sure all air is gone from that line. Then do the same with the right front. Then the left rear, then right rear. This is gravity bleeding, no pumping required. It's the only way to know for sure that each wheel cylinder and line is free of air. Only let the master cylinder drain down about half way each time the tighten each bleeder. Refill with the drained fluid. Be patient my friend, it takes time to do it right, but it works for me every time. Good day.

One of the wheel cylinders is leaking, pulling air back into brake system and it's going back to the4 master cylinder. Look for brake fluid leaking at one of the wheel cylinders, that's where the problem is.

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Hello,
I hope this helps.







Thank You,
Roy

did you see if they need replaced?
and also the emergancy cable may be froze

If you haven't already, check your rubber lines for weakness; they could be ballooning under pressure.

Bleed right rear,left rear, right front, left front in that order to be sure of good bleed but the brake booster makes it easy to push pedal. Make sure of no leaks from master cylinder. Otherwise brake hoses being soft will also hurt baking quickly.

have one person in the blazer pumping the brake pedal and then hold to the floor, crack the bleeder then tighten, release pedal, repeat till all air is out one side at a time, if this does not work then your ABS unit is bad witch if u follow your lines from your master cylinder u will find a black box with a motor on it, or the master cylinder itself is bad, it also can cause u to have no pedal, replace the master cylinder first, most likely cheaper.