Anyone replace ABS Control Module/Brake Booster??

With it having oil rings on the mounting plate, it would have brake fluid going into it, so at the very least it's going to take a special service tool to help bleed the air out of it once installed I would think.

As long as the master cylinder isn't messed with most anyone can bleed the brakes after messing with brake lines, calipers, etc., but with the modern ABS brakes system, once you open up the master cylinder in any way it's going to take a special service tool/scanner to open and close the ABS valves to release any trapped air when trying to bleed the master cylinder.


So what would be the consequences if there were air left in the MC??
 
So what would be the consequences if there were air left in the MC??

You would have a spongy and not a full brake pedal and lack full braking power.

Air compresses, brake fluid does not, so that's why the pedal would be spongy and lack a full pedal/braking power, i.e. not as much force applied to the brake pads to stop your vehicle properly.
 
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no new details really, except the ABS light has joined the club. drivability the same.

a little backstory on the current master cylinder. this isa one family owned 4runner, but i wasn't directly involved at 111k miles when the original started making noises. the then owner sourced a replacement at a salvage yard w/85k miles on it. because of the plastic module damage, i'm thinking they told the salvage yard they need a brake booster, and the yard sold one at discount because of the damage to the module, assuming the original module would be swapped over. that never happened, and we have been driving with the cracked plastic since 111k. over time, moisture may have entered, damaging the module. so the booster is fine, but the module is not, causing electronic flakiness. that's my theory.

best option is too replace the whole unit. i could probably sell the booster side for a couple hundred to recoup some costs.

Do you have the original first skid ECU?? Maybe it's fine. Can you please pull all DTC codes. Do this manually via DLC not with a scanner. This gives every code including ABS and VSC. I have some ideas what the issue may be but prefer to see all codes to pinpoint the problem area. Was the problem ever fixed by the dealership or mechanic?? What was done and how long until the problem came back? Or has it not been resolved at all?
 
sold off the original booster several years ago. it was just gathering dust, and had an issue, so had no reason to hang onto it.

DTC/DLC: refresh my memory. any how are they manually pulled?

this concern probably first appeared over a year ago, when i was told my brake lights were always on, and by then the dash lights were also on. besides the dealer diagnostics, no work has been done.

remember, the module case is still damaged and should be replaced anyway.
 
i don't know if it is disable. a while back i was starting up a street hill in 2wd, and i could here the stability control kick in and the wavy car symbol briefly kicked in.

That light is always on with the abs light you said and should be if the brakes lights are constant on. So the issue is intermittent? I just read the last gigantic thread to remember. The instructions on how to pull codes manually I posted there for you already. It like a five minute procedure. When you replaced that brake plunger switch way back did you just replace that or the whole pedal assembly..?
 
That light is always on with the abs light you said and should be if the brakes lights are constant on. So the issue is intermittent? I just read the last gigantic thread to remember. The instructions on how to pull codes manually I posted there for you already. It like a five minute procedure. When you replaced that brake plunger switch way back did you just replace that or the whole pedal assembly..?

trac light: yes, always on, but it flickered on that instance, like it was engaged.

brake lights are not 100% on. often they are on through all ignition settings, including key out. but not always. when the brake lights are on, if i slam the drivers door, they flicker. rarely, that causes them to turn off. if i slam the door again, they likely turn on.

recently noticing sometimes ignition key chime will go on when i pull the key out. need to re-insert key and pull out again to shut it off.

plunger: bought new plunger, didn't fix anything, replaced with one that was in, which i replaced at 200k after brake job, due to brake dash light on. however, tech had done poor job installing brake line causing leak, so that was why that light appeared. have not replaced any of brake assembly. did pull plunger, manually engaged it, no difference.
 
You would have a spongy and not a full brake pedal and lack full braking power.

Air compresses, brake fluid does not, so that's why the pedal would be spongy and lack a full pedal/braking power, i.e. not as much force applied to the brake pads to stop your vehicle properly.

Gotcha, thanks for the explanation.
 
The instructions on how to pull codes manually I posted there for you already. It like a five minute procedure.

feeling slightly lazy, if you exactly where that post is, could you copy/paste it here and add and other instruction?

seems like a used master will run $400-$600, depending type of sale and mileage. new is $1200. i would think used should be about $300+, depending on condition etc. 50% new seems high.
 
https://www.toyota-4runner.org/3720836-post167.html

Here what blackworks says on this old thread is really the mindset you should try to go towards. We really need to rule out the inputs to the computer. Even if you do want a new one it still will be disabled if the problem was an input.. reckon that test light and multimeter need to get busted out! Chitty chitty bang bang Does the parking brake light ever come on intermittent since your fluid leak?
 
The instructions on how to pull codes manually I posted there for you already. It like a five minute procedure.

feeling slightly lazy, if you exactly where that post is, could you copy/paste it here and add and other instruction?

seems like a used master will run $400-$600, depending type of sale and mileage. new is $1200. i would think used should be about $300+, depending on condition etc. 50% new seems high.

Haha I'm completely blunted and not that lazy yet! It's in there somewhere I might look later if you haven't.
 
https://www.toyota-4runner.org/3720836-post167.html

Here what blackworks says on this old thread is really the mindset you should try to go towards. We really need to rule out the inputs to the computer. Even if you do want a new one it still will be disabled if the problem was an input.. reckon that test light and multimeter need to get busted out! Chitty chitty bang bang �� Does the parking brake light ever come on intermittent since your fluid leak?

my friend, that fluid leak happened at 200k miles in august 2018! this is 2022. no, the parking brake light never comes on.
 
my friend, that fluid leak happened at 200k miles in august 2018! this is 2022. no, the parking brake light never comes on.

Ok because that could be a possible symptom. That 46 master pressure sensor code that the tech didn't bother with is something I would want to troubleshoot. It's actually a sneaky part of the stop lamp circuit which needs troubleshooted also. Those sensors within the master are actually the ones that signal the stop lamps on or off when they detect hydraulic pressure within range. I believe I posted that diagnostic procedure already also.
 
Pull codes manually via DLC-
Turn a/c system off,
Jump terminals TC and CG (4, 13) with appropriate sized wire or something similar. Make sure you're looking at the DLC right to jump the right terminals it's upside down on mine. Don't blow it up �� Just DON'T f_ck up the terminals by spreading then out!! Turn ignition switch to on. Codes will be blinked at the check engine light, abs light, VSC light, possibly the cruise control light. Let know if you need the complete check/clear code procedures and how to read the blink patterns. Turn ignition off and pull key, remove jumper from DLC.
 
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DTC: diagnostic trouble code?
DTL: diagnostic trouble list?
DLC: dash light code?

wire to use: paperclip?

be aware, i am NOT getting a CEL
 
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DTC: diagnostic trouble code?
DTL: diagnostic trouble list?
DLC: dash light code?

wire to use: paperclip?

be aware, i am NOT getting a CEL

Correct on DTC, never heard of DTL, DLC -data link connector. A thin paperclip might work just kind of test it to make sure you're not gaping the female terminal I like a small gauge copper wire stripped on the ends.
 
ok, took a couple pics of the OBD2 plug. i assume that is what you mean by "data link connector"?

starting at the top, count 4 in, place one end of jumper, keep counting to 13, place other end of jumper.

turn key to ON.

now, will all the lights start blinking? what kind of numerical codes should i expect? low numbers of blinks, high numbers? do i have to record each lights blinks? they will just keep cycling through until jumper removed?

reading/clearing: that would be helpful. won't proceed until completely ready.
 

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couldn't wait any longer:

ABS: 4 flashes
VSC: 4 flashes
TRAC: not visible
CRUISE: constant flash
CEL: visible, no flash
 
Yes that's the connector but it sounds like you did it wrong. It's upside down in your truck too like mine. Here are the TOYOTA instructions. Notice the connector is a trapezoid shape. Make sure you look at it in the correct orientation. Sounds like you may have tried it backwards. These instructions show a picture of the pins to jump. The codes should be blinked in two digit intervals..

Toyota 4Runner: Dtc Check / Clear - Vehicle Stability Control System(for Hydraulic Brake Booster) - Service Manual
 

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