soft pedal after wheel bearing

OhNoA2.0 · Post by **OhNoA2.0** » Mon Jul 18, 2011 11:57 pm

I just replaced my front drivers side wheel bearing and while test driving it, i noticed that my brake pedal is very soft. I can floor it but there is still a bit of pressure. I looked around for leaks after pumping the pedal a shit-ton and didn't see anything. I checked my brake fluid level, that was fine. But I noticed that my brake fluid is VERY dirty, a dark brown....any ideas?

ZeroChad · Post by **ZeroChad** » Tue Jul 19, 2011 12:21 am

After making sure the rubber brake line isn't leaking at the caliper or up by the hard line, I would give the brakes a good bleed and go from there.

hansken_yo · Post by **hansken_yo** » Tue Jul 19, 2011 1:41 am

Depending on what your levels were before you started the work you could have drawn air into the system. when you flex the lines as such you do push fluid out, but if your levels are good you shouldn't draw air into the system and the pedal should firm up after a few compressions. If it is still just dropping to the floor definitely start with bleeding the brakes and making sure your fluid levels are good.

OhNoA2.0 · Post by **OhNoA2.0** » Tue Jul 19, 2011 10:39 am

I will be bleeding them shortly...any clue what could cause the dark brown fluid? It was just changed last year. I may change it again

hansken_yo · Post by **hansken_yo** » Tue Jul 19, 2011 12:41 pm

Dust. It gets in there

Post by **occasional demons** » Tue Jul 19, 2011 2:29 pm

Heat.

Your outer pad conducts heat to the piston. It is then transferred into the fluid. Also the normal wear of the o rings will help darken it.

When you changed the bearing, possibly pushing the caliper piston in to disassemble/reassemble the brakes somehow let air in.

Plus, unless you used some kind of pressure fill to flush the fluid, bleeder by bleeder, you didn't get all the old fluid out.

Even then, there may be some in the calipers/cylinders that remains. But that is nitpicking.

OhNoA2.0 · Post by **OhNoA2.0** » Tue Jul 19, 2011 5:54 pm

My car is bipolar, I swear. I took my wheels off, checked all the lines, fluid level ect. Got in to pump the brakes and they feel fine. I guess there was just some air in a line.