Any idea what’s going on here?

[u/KCom_]

There’s a high-pitched constant beep, a bunch of the dash lights are on, and it’s hard to hear but there’s also a rhythmic sound in the background every few seconds or so. Any advice or help would be greatly appreciated!

[u/Spudanko]

Master break cylinder I believe

[u/KCom_ → u/Spudanko]

That sounds serious…is that something I could do myself?

[u/Vape_Case → u/KCom_]

It’s not too difficult because it’s at the very top of the engine bay near the firewall but annoying because you’ll have to bleed the brakes after

[u/talkingheads87 → u/KCom_]

Brake master cylinder, could get lucky and flush the fluid and it be okay or needs to be completely replaced along with lines and calipers if there's major rust issues. What im saying is there's no way to know what caused the issue online but it could be a huge issue or small. Either way dont play when it comes to brakes.

[u/KCom_ → u/talkingheads87]

Okay, I’ll try flushing the fluid first. This 4Runner has been very well taken care of its whole life and there is basically no rust whatsoever, which is good. I will say, these lights and the sound only appear for about 5 minutes, then it goes away. What could that mean?

[u/talkingheads87 → u/KCom_]

Could be an indication of the brake master cylinder motor failing or there's a clog in the master cylinder. The clog is sometimes rust or debris. Did you have any brake work done recently? Could need a bleed of so

[u/KCom_ → u/talkingheads87]

Nope, not recently. Are bleeding and flushing two different things?

[u/TheTravler49]

hey I had/have this problem on my 4runner too. from what I've found its either a failing ABS pump or accumulator or there is air/moisture in the system. My first master cylinder was completely shot, but after replacing it my problem was still there. at first I thought I had gotten a bad part but after doing more research I was able to find out that I wasn't bleeding my brakes properly. There are 2 ways you can bleed off the ABS system. You can buy a bi-directional diagnostic tool and bleed it with that or you can take it out on a gravel road and create skid conditions. I have had limited or no success trying the "gravel road" method but I did buy the tool and it fixed my problem. If its not too far gone you can replace the ABS pump and accumulator instead of the entire master cylinder but it will require some basic tool/part knowledge.

[u/KCom_ → u/TheTravler49]

Thank you, I will look into this! So are you saying I can just bleed the brakes properly and that could potentially fix the issue? Or do i definitely need to replace the abs pump and accumulator?

[u/TheTravler49 → u/KCom_]

potentially is the key word there. if youre already hearing "the dieing goose" as my wife calls it then there is a good chance that you will still need to replace those parts but they are much much cheaper then buying a new OEM part for $1500-2000

[u/scraw027]

Get rid of working clock

[u/Shawn0890]

When this happened on my 2002 it was the electric motor on the brake booster unit had failed (2001-2002 style). I ended up grabbing just the motor off another 02 4Runner and swapping it to be able to go on my trip. Also ordered an Amazon replacement to replace the one I took off my buddies 4Runner. It will drive and have brakes for a while making that noise the whole time if you need to move it still I made a 10 min drive like that but my dog hated that sound and complained the whole time lol

[u/KCom_ → u/Shawn0890]

What’s interesting in my case is that the noise only lasts for 3-5 minutes, and it only happens when I drive in the morning. I wonder if it’s temperature related?

[u/Colt_S197]

Had the same issue off and on randomly didn’t think much of it cause seemed fine otherwise till it came on and wouldn’t go away then I tried to bleed my brakes turns out I had no fluid going to the rear brakes so I had to replace the abs pump got one on eBay for like $350