I was told by the local mechanic that I need to replace the “master cylinder with electric assist” and that he couldn’t find any since it’s such an old car. I think I have found some online but it’s named something different. Is there anyone here that can help me find the part I need? Send me in the right direction? I will attach a picture for some reference. Thank you for the help.
2003 4Runner Master Cylinder Question
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He just said it was bad. I took it in because it was giving me lights and alarms, as well as the brake would sometimes not work. It seems to be fine now, but I’m not gonna risk it. I was hoping i could find the part a little bit cheaper than that. I’ll keep looking. Thank you so much for the help!
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It was/is leaking brake fluid but it seems fine now. Sometimes you had to really mash the brake in order for it to work, on top of the warning alarm going off. There are some lights on the dash as well. I’ll upload a picture of it once I get a chance. I just wanna make sure my daughters car is safe.What are you experiencing? Low pedal? Noise?
Sorry I didn't read the reply.
If that is the case please stop driving it since it is your daughter driving it, she may not know how to react if it fails and get in an accident. There are other sources to get a new/rebuilt unit, I have the same problem with mine but not to the point I am losing brakes my issues are with the pump/accumulator.
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Oh, I do NOT let her drive it nor does anyone drive it. I have her using my car. When I run it or drive it around our neighborhood to check it out, it seems to be working fine. I’m not letting her behind the wheel of it until it is fixed.
It’s a common failure. Mine gave up after 20 years and ~200k miles.
The assembly should still be available from the dealership.
The assembly should still be available from the dealership.
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These things are quite robust but the motor brushes and bearings could be the culprit due to age. You can buy both parts easily from the usual places. Listen to the ABS motor running when you first turn on the key to IGN, and see how it sounds. It typically comes on few seconds when you start the engine but not very noticeable over the engine sounds. I grabbed a spare one from a junk yard and rebuilt the motor then stuck it on the shelf as a spare.
Can you elaborate on this please? How did you rebuild it? What is being rebuilt? Is there a tutorial anywhere? Mine seems to be working fine but I’ve got 230k miles and I’m sure it will happen eventually. I don’t love the idea of dropping $1k on a new part but if rebuilding is an option, I’d like to study that some.
Thanks!
Holy cow, this was a while ago and i've consumed a fair amount of weed and wine since then. Let's see, i'd treat this motor as a typical DC motor with brushes. So, jump on YT to see what I'm talking about, but here's the run down.
Separate the motor from the whole kittenkaboodle, stick it on a table. Take it apart, then blow it out with compressed air. Take the brushes out, then measure them and order replacement from Amazon or your local motor shop. Take a look at the bearings for a part number, cross reference, then purchase and swap out. With a high grit sand paper, gently make the commutator shiny again, then reassemble and you're GTG. It's really that easy, but do look up YT videos to give you extra confidence.
If you wanna get all geeky and $hit, before doing anything, hook it up to a 12vdc battery source, run it and measure the current draw. Then do the rebuilding thing, and re-do the current draw test to see if it now draws a little less current, meaning the bearings were causing a slight drag.
My ABS is at 450k and still running strong, but I have a backup just in case. As a PM item, i'd use the ABS system + Techstream to flush the whole system with fresh clean and "dry" brake fluid, perhaps every other year. You can use a power bleeder like a Motive brand, but the ABS system might have old fluid in it still, but i'm not really sure. The Techstream process is nice with a second person handling the computer while you open and close the bleed nipples.
Hope this helped!!
edit: something just came to me. I vaguely recall one of the bearing was hard to source, but not 100% positive.
Holy cow! Thats a good, yet somewhat comical, response I wasn’t expecting! Lol
So, the issue people have with these things is the motor going bad? I wasn’t sure what the problem was. Now I know.
I’ll need to research this bleeding process you speak of. I presume the old fashioned “wife pumping the brakes and me turning the bleeder” won’t work?
So, the issue people have with these things is the motor going bad? I wasn’t sure what the problem was. Now I know.
I’ll need to research this bleeding process you speak of. I presume the old fashioned “wife pumping the brakes and me turning the bleeder” won’t work?
I think there maybe couple of issues. The motor bearings may go bad as well as the commutator brushes simply due to years of operation. Second thing maybe is "crud" in the lines from maybe coming up from the calipers due to a lack of regular flushing? I mean think about it like this. An ABS block is nothing but a valve body with bunch of solenoids opening and closing when the ABS system is engaged; ie , slick surfaces, skid prevention, ATRAC and DAC activation, etc. So, if a piece of debris gets stuck in these tiny orifices, you can guess what happens next. The solenoids are good for a gazillion cycle of activation and they aren't working a whole bunch until the feces hit the oscillating modulator, so to speak! So, they mostly just hang there in stand by mode for the bulk of their lives.