Poll on total brake failure in 100 series (6 Viewers)

[2001LC]

No weep or leak anywhere, bone dry. The bleeders on all for corners even have a silicone cap on them. Didn’t touch the brake system at all since last full flush/fluid exchange on April 2021. Curious to hear your experience on your 100s if this is ab/normal.
View attachment 3194721

Are you showing level difference! If so, did you following what is embossed on reservoir, as to how to set level both times (pictures)?
Also note; as pads wear pistons of calipers push out of caliper. This increase fluid in chamber behind piston, and reduce level in reservoir.

 

[OEMGUY0720]

Are you showing level difference! If so, did you following what is embossed on reservoir, as to how to set level both times (pictures)?
Also note; as pads wear pistons of calipers push out of caliper. This increase fluid in chamber behind piston, and reduce level in reservoir.

Yes Paul I’m showing the difference of levels. Good point on the pads wearing, I didn’t thought of that until you mentioned it. The Lx ran around 7k miles from April 2021 through Dec 2022. I did topped it off yesterday and will continue to monitor. Thank you.

 

[Biga27110]

My pump is coming on often I suspect its the accumulator is that an easy just unscrew from the top and screw in the new one? I cant find any info on this.

 

[jms72]

You can just replace the accumulator motor without having to replace the whole assembly, assuming its just the motor, which it normally is.
However, if you can hear the motor coming on, and it never stops, or takes way longer than normal to turn off, chances are its the accumulator pump or reservoir, and not the motor.

The motor is attached to the accumulator pump with two allen key bolts.
I removed the air intake filter box first to gain more access.
Disconnect the power cables by undoing the phillips screw first.
You need some long handled allen keys, the standard ones are too short to reach the two keys.

Its a bit of a PITA, but easier and faster than taking out the master cylinder, and no need to bleed the brakes afterwards.

I overlooked your name and location before seeing your comment about removing the air intake filter box first and was like wait, what? Why? Then I saw you are in Australia. Are you aware of a video that details the process you describe? I find several where they are pulling out the entire assembly and I try to visualize it better but nothing is very clear. I'm around 220,000 miles and would like to change this before it goes and would love not to have to pull everything out and bleed afterward.

 

[FxFormat]

It's time to replace my front pads and rotors, i think one of my caliper is seized as well, uneven wear on one side. Taking this opportunity to go a head and replace the calipers as well, is there a difference between the years? Or are they all the same. Thanks.

 

[okoverland]

Anyone know why I can't bleed all 4 corners with tech stream? I only have the option for fronts.

This is a 1999 LC.

 

[DrHess]

The ABS air bleed thing only does the front lines. You bleed the back ones like any other brake system.

 

[okoverland]

The ABS air bleed thing only does the front lines. You bleed the back ones like any other brake system.

OK, thanks. I keep seeing other videos and photos where there are 4 options listed. Maybe it's different for other years.

 

[archie]

no, 2004 with 110k

 

[UltraFJ40]

No problems yet, 2005 w/ 156K or so

 

[Kieron]

Hi all my UK spec 4.2 Td brake pipes had corroded over the years and I replaced quite a few sections after one blew completely. But if these are the first repairs at about 180000 miles and nearly 20 years old I don’t think thats too bad.
I’ve had Mercs a lot newer and much lower mileages and every mot ,Vehicle Examination, they commented on corroded brake pipes
I have had to change callipers etc but they are expendable components

 

[Biggunns]

I wanted to see if a theory I have might be true.

I have been chasing an issue for the past month with my 00 LX dieing randomly. At first it started showing signs of a misfire with a new denso coil pack, then an O2 sensor on the same bank. It drove fine for a week then started dieing when idling or when I came to a stop. The idle seemed a little rough so I pulled the fuel injectors, cleaned them, replaced the screens and o-rings and checked fuel trims on Techstream. It drove fine for 3 days even some off-roading.

Then it happened again this week at 2 stoplights (dies right when I came to a complete stop, no CEL) then as I came to a stop in traffic it almost died but then I got the ABS/Brake lights and buzzer. When I pulled over I checked everything over and gave the accumulator whack and the engine sputtered and almost died, I hit it 3 more times and every time it did the same thing.

I pulled the brake master cylinder assembly found the the brake booster pump terminals were corroded and the boot was filled with brake fluid from a weeping leak from behind the ABS module.

My theory is that when coming to a stop the booster motor was shorting out through the fluid in the boot causing the engine to die and not throw a CEL code.

 

[Biggunns]

I wanted to see if a theory I have might be true.

I have been chasing an issue for the past month with my 00 LX dieing randomly. At first it started showing signs of a misfire with a new denso coil pack, then an O2 sensor on the same bank. It drove fine for a week then started dieing when idling or when I came to a stop. The idle seemed a little rough so I pulled the fuel injectors, cleaned them, replaced the screens and o-rings and checked fuel trims on Techstream. It drove fine for 3 days even some off-roading.

Then it happened again this week at 2 stoplights (dies right when I came to a complete stop, no CEL) then as I came to a stop in traffic it almost died but then I got the ABS/Brake lights and buzzer. When I pulled over I checked everything over and gave the accumulator whack and the engine sputtered and almost died, I hit it 3 more times and every time it did the same thing.

I pulled the brake master cylinder assembly found the the brake booster pump terminals were corroded and the boot was filled with brake fluid from a weeping leak from behind the ABS module.

My theory is that when coming to a stop the booster motor was shorting out through the fluid in the boot causing the engine to die and not throw a CEL code.

View attachment 3237510Sorry tried to attach the photo to original post.

 

[UZJ100LC]

went to inspect my brake system today. takes about 28 - 30 seconds to finish after turing on from sitting all night.
Question: is it normal the for the brake booster cylinder to shake every 5-10 seconds as it pumps?

 

[2001LC]

Some shaking is normal. I would suggest, timing a second time after key off pumping pedal 40 times. In the 200 series FSM states repeat 5 times. As always battery voltage should also be checked, during testing.

 

[UZJ100LC]

Some shaking is normal. I would suggest, timing a second time after key off pumping pedal 40 times. In the 200 series FSM states repeat 5 times. As always battery voltage should also be checked, during testing.

Thank you for the tip, will do.

 

[Beau]

Currently at 258K and finally think I should tackle this. My chime came on for two seconds the other day and I can hear the motor run for about 35 seconds on start up, so I believe I’m living on borrowed time… so I have two options and want to run it by you all. I think I’ve made my decision but I always like to hear people’s thoughts.

Send it off to get rebuilt - $930 (including shipping) - not sure if it’s getting rebuilt with OEM parts but it comes with 1 year warranty. People do speak highly of the rebuild dude and he’s well known within the cruiser community. I’d get a $250 core refund, probably closer to $170 after shipping so my possible cost would be $760

OR

NEW UNIT entirely - $1380 inclusive of tax and shipped to my door. Brand new so it should last another 20 years/200K miles. Not sure I’m gonna have the truck that long but you never know.

So my price difference here between rebuild and new is $620. However with the new unit, I still have my old one and reckon it’s at least worth $250-300 to someone. Still works but I reckon it’s not got much more life in it. Heck, I asked a known parts breaker on the UZ100 group on Facebook and he sells used units with 150-250K miles for $700, which I think it wild but hey, I guess that’s what people pay.

So if I sell my old unit for let’s say dirt cheap $250, my net cost on the new unit is $1130. $370 more than the rebuilt on. The new unit is what I’m swaying towards…. What would y’all do? I also figured if I sold this truck in 5 years time, someone would probably pay a little more of a premium knowing it’s got a brand new brake assembly vs a rebuilt unit. (I know I would)

 

[2001LC]

First: I'd not buy rebuilt. Doing so you'll likely replace again in a few years, which will reduce reliably and increase long term maintenance cost..
Second: "My chime came on for two seconds" Could mean a few things, to name a few: Seals leakage in master and or in calipers.

This whole idea of buying a rebuild master, is a bad one. First a rebuilt was presumable a master that failed. Not knowing the key point about condition of that masters fluid, is asking for issues.

What is not rebuild-able:

• Masters internal seal.
• ABS unit (black box on side of master).

What is rebuild-able or replaceable as a component:

• Accumulators weaken or even leak with time.
• Pump and its seal weaken with time.
• Booster motors wear out.
• Master plunge seals, wear out.

Brakes ...... Overdue write-up on brakes. - https://forum.ih8mud.com/threads/brakes-overdue-write-up-on-brakes.1230968/

 

[Beau]

That was my thought process and why I ended up ordering a new unit. The price savings going rebuilt wasn't enough, but I think when these things were $2K+, I would definitely have probably opted that route.

 

[cwilsun]

So to contribute a bit: 2005 LX470 250k miles. No brake failure
Just purchased a 2007 X470 140k miles. I have intermittent ABS, VSC TRAC, VSC OFF, lights pop up with codes of C1223, C1246, C1249. No brake light warning. Lights clear once ignition is turned off/on. Performed the ignition off, 40 brake pump test several times and it usually pressurizes by 28 seconds (no longer than that). No squeal heard. Has anyone seen this prior to a brake failure?
Thank you