Gen III ABS woes

Sabre

Overlanding Nurse
EDIT: PROBLEM FIXED! See post #8, below, for "how to!"

Is this the dreaded brake booster accumulator leak? The HBB motor itself? The ABS ECU?

Symptoms: electromechanical "cluckcluckcluck" sound from booster motor when braking and also at random times. No ABS light, no fault tone, no OBDII codes. Brakes work normally except when braking hard on gravel, when the ABS light and high tone come on and there are 4 locked wheels and no pedal pulse.

But here's the thing: this happened right after fording a deeply flooded trail. It can't be coincidence (well, sure it can, but it seems unlikely).

It was wet all over the place under the hood, so I checked fuses, relays and fusible links...all OK. I pulled the ABS relay & the noise persists. Pulled ABS fuse and noise persists. Wheel sensors look OK. Disconnected battery to reset master ECU...problem persists.

2001 Limited, unknown if HBB recall ever done. Ugh...I guess I'm going to have to submit myself to the dealership for their special ABS ECU scan tool.

Thoughts?
 
Last edited:

earljuic3

Adventurer
Also I think the recall is only good for 10 years from manufacture


Sent from my iPhone using Tapatalk
 

Sabre

Overlanding Nurse
Yeah, that's the noise. You did the work yourself? There are dire warnings online about working on the ABS system....
 

Marutuk

KK6WFB
I had my mechanic do it, it wasn't a big task from what he told me, but I didn't feel confident enough to replace a system like that myself. :)
 

earljuic3

Adventurer
See my thread on page 1 of the mitsu forum if you want to read about what kind of issues this accumulator problem can lead to.
 

Sabre

Overlanding Nurse
OK, to recap, there was an odd noise and occasional beeping and flashing of the ABS light. Earljuic3 was exactly right in that it was the accumulator; the water crossing was merely a coincidence. Marutuk captured the noise perfectly in this 3-second clip:
[video]https://youtu.be/txaUnPgZO-k[/video]

I got the ABS accumulator from Daytona Kia-Mitsubishi in Florida (via eBay) for $99. This is what arrived:
23464682892_e5037221e7_k.jpg


Here's where the beast is located. It's the rounded black thing on the 2001. On later models it looks like a cylinder rather than a sphere.
23490793091_d96e4d1410_k.jpg


Here is what it looks like after removal. It's upside down in this picture. You can see the threads up at the top. It simply screws into the brake system.
23464688052_1fa92757e4_k.jpg


Here's the technique:
1. With the key OFF, pump the brake pedal 40 times.
2. Wrap an old rag around the bottom of this area to catch spilled brake fluid.
3. With a 21 mm socket, remove the accumulator. NOTE: it's on there REALLY tight. I spent 5 minutes dicking around worrying that I was going to break something. Don't use an air tool or impact tool. Just give it a big old grunt and it will come loose.
4. When you remove the thing, you'll see poking up from the brake system a rod that has some black o-ring looking things and a spring. Push this down into the housing so that just the rod is poking up. The accumulator fits over this rod.
5. Set the accumulator down over the little rod, seated on the threads. Carefully start the threads and hand-tighten. Torque to 40 lb-ft. Wipe up spilled fluid.
6. Turn the key to the "on" position. Listen to the little pump running (I couldn't hear it well from the front seat...it's not nearly as loud as the weird noise I had been hearing when there was a problem).
7. After the pump stops running, turn the key off and pump the brake pedal 40 times.
8. Repeat steps 6 and 7 four times. You should feel the pedal tightening up as you get to the 20th pump or so each time.
9. Top off the fluid reservoir if needed. Mine only lost a tiny amount and didn't need replenishment.
10. Test the brakes carefully.

Problem solved. No noise, ABS working perfectly. Total time spent doing the work: 18 minutes. Five of that was grunting, swearing and worrying when I couldn't unscrew the little devil.:REExeSquatsHL1:
 
Last edited:

earljuic3

Adventurer
Great write up. Mission success. Keep close eye on your the quality and cleanliness of your brake fluid so you don't end up with a 2500$ fix.


Sent from my iPhone using Tapatalk
 

BOPOH

Explorer
Thanks for sharing! since i dont have Gen3 i just have a question about step 3 - what's the logic behind "Don't use an air tool or impact tool"? I've always been told that impact and vibrations helps to loosen things safely. Not hating, just trying to educate myself
 

earljuic3

Adventurer
A repair like this generally requires finesse, using an air tool or an impact wrench could damage the equipment by "forcing" it to come off.
 

Worshington

Observer
Sabre,

I just wanted to let you know how much I enjoy your write ups. Many of the maintenance riffs you've put up here have been both inspirational (your trail armor, cladding removal thread) and extremely detailed and helpful (such as this and your bearing/hub thread). If you are ever on the Olympic Peninsula, look me up because I owe you a beer.

Cheers,

Jason
 

nckwltn

Explorer
Something I noticed.... I have a W220 mercedes with the hydraulic suspension... it also has accumulators that go out.... they look VERY similar.

Also, in my '03, I had the motor fail in the HBB pump.... I ended up pulling the motor from an HBB out of a 4 runner of similar year.... in my video you can see how bad the motor rotor is worn, from the brushes.... I would expect that you'll end up having the same problem soon.

 

Forum statistics

Threads
185,527
Messages
2,875,533
Members
224,922
Latest member
Randy Towles
Top