C1391 and brake fluid level

depends on how quickly it is disappearing. keep a close eye on it

 

tbh, i don't recall leaking fluid in any of the threads i've read, but it may be the case. check all the wheel connections as well.
how long time/miles has it been since you last noticed the fluid level?

 

that's what i was thinking. i never check mine either. hopefully, it's just typical loss over 17 years, and it got low enough to set a code

 

Most of the time, a C1391 code will turn out to be an internal leak. You would never see any fluid going out of the system; it is just getting around the valves inside and trickling back to the reservoir.

A level below MAX at the reservoir is normal and expected if the system hasn't been zeroed down. Did you zero it down before you checked and topped off?

When the system normally runs, it pumps some fluid out of the reservoir and into the pressurized accumulator, so the reservoir level goes down. To "zero-down" means to have all the accumulator pressure released so that the fluid is back in the reservoir. The level markings on the reservoir are meant to be checked while zeroed down. If you top off to MAX while it isn't, you'll be slightly overfilled.

The level also gradually drops as the brake pads wear (in addition to the way it drops when not zeroed down). At the factory, it started out at MAX when the pressure was zeroed down and the pads were brand new.

So from the level you described, I'm not convinced it was even low, necessarily. That makes me cautious about assuming that your topping-off will be a lasting fix.

 

I was over by a few hundred miles and they told me to get stuffed. Last Toyota I'll ever buy (new at least). They will get exactly none of my money ever again.

 

only problem being, no other mfg will either