hello sages- here is somewhat of an oddball question which i havent seen come up before here, probably since sl6 vehicles even the last ones predate abs cars i think. i will need to bleed a brake system on a 2001 blazer(gm) since i will have to replace a seized caliper and therefore open the brake line to get off the caliper. in addition to pedal bleeding that wheel which ive done plenty of times on a non abs car to finish the job what steps do i have to take to bleed the abs box if that is necessary. local contacts dont know or have given me bs answers. seems to me if you dont introduce air before the abs box by opening the master cylinder lines, but are working at the end of the system, it shouldnt make any difference . but not sure. looking for reliable advice from our doctor, uncle dan or the DI but will be grateful for any sage. thanks tons paladin

Here are a few articles on ABS bleeding here, and here

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

even if u totally drain the system u should be able to bleed it like any other,
We don't do anything special at work and I change a lot of brake lines

Kevin

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crossthreads are better than locktite

hi sages - thanks for all your comments. replaced the LR stuck caliper, 4 rear pads and smoothed the LR rotor. noticed the abs box on the right side frame under the front passenger door. found no bleeder screws. found a number of brake lines going in and out of it . elevated the LR wheel, kept the masters resevoir full and pedal bled the caliper successfully. apparently did not have to worry about air getting in the abs box since everything was downstream of the bled caliper and undisturbed. still leaves unanswered whether if air got in the abs box((as in a master cylinder replacement) how would you bleed the box. surmise you would have to bleed the new master first at its fittings, then bleed the box at its fittings. hoping abs sages will evaluate my analysis. thanks tons paladin

I was once told that you had to do it at each wheel with the car on, no pumping... crack the screw, down on the pedal, make a ridiculous mess, close the screw.. repeat until drowned

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63 Valiant 200
64 Dart 270
73 Fury II
84 Cherokee 2 dr
86 Dodge W-150
73 Volvo 144
74 Volvo 145
81 Volvo 245

I have several Bendix brake service training manuals, which I use, before any major brake job, to see if there might be any "gotcha's". Without looking I can't say which cars, But there are some, that under certain conditions, you must use a bidirectional scan tool to activate the pump motor. Also not all cars use the same wheel bleed sequence (RR, LR, RF, LF). It depends whether the system is split front/rear or split diagonal.
Also some velicles have a bleeder screw on a valve in addition to the ones at the wheels. My Toyota pickup Has a load sensing Proporsioning valve which must be blead after all wheel cylinders.
PS: Volvo has some, if not all their 4 wheel disc cars brakes split between calipers on the same wheel.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Right, Volvo's system used to be setup so that three out of four wheels were on one circuit, and both circuits overlapped.. so both circuits fed both front calipers, and each had it's own rear wheel on it as well.. They started that in '72 or '73 I think... I doubt they still use that exact distribution system, I'd imagine that it's gotten more complicated over time.... Those were a pain to bleed. Not as bad as a Rolls Royce/Citroen/Bentley though. Those had pressurized "spheres" driven off of the cam, that raised the pressure to some ridiculous level, and in order to bleed the full system, since they had dual calipers on the front wheels, (Rolls) you had to crack about 16 bleed screws by the time you were done, I think there was two per caliper, one on each sphere, dist. block, master cyl... and so on. Worst yet, if the system ran dry for any reason, you then had to bleed the suspension, because it was hydraulic as well. Part of me wants to think that there were bleed screws on top of the shocks in the trunk. Because that's where every Rolls Royce customer wants their mechanic to spill brake fluid. The amusing part, is that they don't even use brake fluid... You had to buy this special mineral fluid from Crewe that cost around $20 a quart. I think the entire system holds 4 or 5 gallons, something ridiculous, anyway.. So, next time you see the ad for a $5,000 '73 Silver Shadow and are tempted (believe me, the ride quality is like no other) remember this, and just think that it's the tip of the maintenance iceberg

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63 Valiant 200
64 Dart 270
73 Fury II
84 Cherokee 2 dr
86 Dodge W-150
73 Volvo 144
74 Volvo 145
81 Volvo 245