Loss of brake fluid

[Riley]

I'd search but don't have time and want to get some feedback tonight before you guys log off....

My wife was driving the 80 tonight and informs me that the brake light is coming on. When she gets home I inspect the fluid and it's right at the min level.

Any suggestions for where/how to locate the missing fluid (i.e which caliper)?

An initial inspection everything looks fine but I guess I need to pull the wheels to have a better look. Any advice is welcomed.

Thanks

edit - It's been about 16K miles since my front pads were done (maybe more). Perhaps the pads have just worn enough to lower the fluid.

 

[Rich]

Your pad wear may account for the drop in level. Depends on how heavy the brakes get used.

 

[Riley]

Thanks Rich, I'm thinking that too now. I guess if no more fluid goes missing for a few days then that's probably it. I'll pull off the front tires tomorrow night and have a peek at the pads and calipers.

I just checked my records, it's been 14K miles on the front pads. I'm one of the few guys that uses the 80 series pads on the front.

It's kinda of freaky when the wife calls and her brake light is coming on. I should have been watching the brake fluid level but honestly I can't remember the last time I checked it.

 

[Rich]

I'm guessing my level has gone from near max to approaching but still above min in maybe 12 - 17 k miles. In terms of pad wear, after 30k miles I was about half way to the wear limit on the pads. From this, I presume topping off the resevior is needed prior to replacing pads. I'm not aware of any leaks in my brake system.

 

[Scamper]

Rich - check the rears too. They can sneak up on you since we really don't expect them to wear as fast as the fronts.

And you'll want to top off the reservoir after you replace the pads...not before.

 

[turbocruiser]

As everyone echoed, wear can account for a slightly lower level but just in case it helps, I'll share that on my rig I was getting the same light without lowering the level and that even with enough fluid to hit the max mark, the light was still on. Turned out to be the rubber cap and styrofoam sensor float thingy that tell the brake light to light when the fluid is low.

To test this you can remove the cap and the plug, clean off the old fluid a little, turn the thing upside down and test the prongs of the plug with a multimeter. When the cap is upside down and the styrofoam float is all the way up (ie empty reservoir) you should get some reading of 8.8ohms or 10 ohms or whatever, when the styrofoam float is all the way down (ie full fluid) your meter should max out.

Anyway in case you add fluid and still have the light, this might help. Ohh, the fix: I just went to the pick and pull and found another matching cap (there are alot of subtle variations btw on various toyota vehicles so make sure you match cap to cap) I specifically asked the yard manager about just taking the cap and he did not care so I got it for five bucks. The plug did not match (I was mainly wanting the cap anyway) but that was simply a matter of cutting the two wires to the new cap and the old plug and connecting them with crimps and wraps. Hope That Helps someone!

 

[cruiserdan]

Almost certainly pad wear. Remember you are filling up 4 piston bores in the front and two pretty good sized ones in the rear as the pads wear. Some 80's eat front pads in as little as 12-14 thousand miles.

 

[John E Davies]

Riley, I suggest you top up the reservoir and just watch the level for a while. In the future you should make it a habit to glance at the reservoir every time you pop open the hood. It takes essentially no time at all and might save you problems.

Call me paranoid, but I pop the hood on all my vehicles at least weekly, just for a look. The other engine bay fluid levels get checked monthly unless there is reason to believe there is a problem.

John

 

[Riley]

Yep, she's topped up and I'm watching it closely. New pads will be ordered once fishing week is over.

Now I just need to decide if I'm going to switch to the 100 series pads and thus need to turn my almost new rotors (PO had put on new rotors before I bought it).