Brake issues with my 100

[JBro]

I have an '04 LC-100 series. When the brake pads were ready to be replaced, I took it to a brake shop that did great work on my old 80-series. After getting the work done, we experienced some bizarre, soft-pedal/push to the floor to get the rig to stop behavior. While unnerving, the problem was intermittent and hard to reproduce.

Took it back to the shop - they inspected and couldn't find a problem. Then, took it to the local Toyota dealer for brake inspection. All looked good but had them flush/replace the brake fluid. While there, we couldn't repro the problem (argh).

So, yesterday, it happend again. Started up after the rig had been sitting for the day, drove down the street and went to stop and... required stomping the pedal hard to the floor and even pumping it a bit to get it to brake adequately. After that, the same behavior actually engaged the ABS.

I'm at my wits end. Brakes are... well... important. Yet, no one has been able to find a problem with the brakes (reputable shop and dealer).

The only thing we can see as consistent is that it happens more on warm days after the rig has been sitting for most of the afternoon. So, as I think about it, I wonder... could this be a seal/brake line that gets soft as the temp rises?

Sorry for the long post but... anyone have experience with or thoughts about this one? I'm getting frustrated and don't exactly want to start replacing parts/entire braking system blindly.

Thanks,
- JBro

 

[Trunk Monkey]

Sounds like air in the system somehow. Maybe replace the MC cap?

 

[Hicaira]

Sounds like air in the lines but since they already flushed it at the dealer and it is still intermittent then I think the finger is pointing at the MC, no?

 

[JBro]

Thanks for the thoughts on this. Yeah - the more I poke around at this and talk with folks, that's the common response.

So, my question: do I just replace it? I've been told that it's "integrated" with the ABS system... not exactly sure what that means. Anyone familiar with this system?

The next question is... what should that cost to have it replaced? I'm to the point where I'm open to focused replacement of parts in the hopes that it resolves it...

- JBro

 

[Hicaira]

I did a quick check and the MC "repair kit" (whatever that is) is about $50. A complete new MC is about $1,600.

Yikes. It it were me, I'd look into repairing before replacing at those numbers (and you still need to confirm that it is indeed the MC. The dealer should be able to diagnose it properly, I'd think).

 

[Trunk Monkey]

Just me, but I would replace the cap before you tear the MC apart, it's like $10. Make sure you've got a good seal on the system.

 

[Jim_Chow]

I would have guessed the electronic booster for the MC is going bad. It's like $1200+ just for that part alone!

 

[JBro]

Thanks all. This is very helpful. And - gulp - nothing like a $1600 MC! Sheesh... Fingers crossed it's not that. Took it to dealer to see if they could repro the problem but no luck... so... time will tell.

But, really appreciate everyone's insight. Awesome - thanks everyone.

Cheers,
- JBro