DOT 5 brake fluid questions

[AJMBLAZER]

So somewhere in the meantime since I last checked my brake fluid my parking brake light has started coming on intermittently. Brakes still seem to work fine.

Checked the reservoir on the master cylinder and the rear is mostly full while the front is very low...

...which I think means the fluid is going to the rear...right? Maybe the shoes are worn down?

No visible leaks that I can find.

At any rate, while I dink with this, I've never had a DOT 5 brake fluid equipped vehicle before. If it turns out to have DOT 5 in it does the true DOT 5 stuff at the parts store mix fine with the DOT 5 that ought to be in it?
Going to go do the test now to see what I have.


Naturally this all happens as I'm starting to daily drive it for most of the next month.

 

[Westech]

you have to get the DOT 5 full silicone Brake fluid. This is what I use from Autozone.. $7.99

 

[AJMBLAZER]

I sorta lucked out. DOT 3. The stuff looked like old DOT 3 and instantly absorbed the water I poured in. Definitely not DOT 5. DOT 5 is better but I had an unopened container of DOT 3 on the shelf. Works for now.

Not a sign of any DOT 5 markings either. Yeah, I know those aren't conclusive but not a hint of them.

Now to figure out where it went.

 

[AJMBLAZER]

Oh yeah, NAPA and Rock Auto mention two different master cylinders with 1605 and 1925 on them...any one know where these numbers would be? Cast in? Can't really see anything on mine.

Interestingly the cap has a warning stamped into it about only using DOT 5. But the way the fluid sucked up that water it CAN'T be DOT 5.

 

[Nick Danger]

dot 5

One way to check is dot 3 is flammable dot 5 is not
plus dot 3 will have a stink to it !