Dirty Brake Fluid in Reservior

[slashnick]

A few weeks back I was checking my fluids and such under the hood and noticed the front brake fluid reservior had dark fluid in it and the rear had light (nearly transparent) fluid. I removed all the dark/dirty fluid and there was some sludge at the bottom of the reservior. Once I got it all cleaned out I refilled it with clean fluid. Today I was under the hood again and noticed the front reservior was begning to get dirty again, but the rear one is still clean.
Why would this be happening? How can I fix it?
Thanks.

 

[corvettedave85]

The rubber brake hoses break down on the inside after years of use. This is the most likely reason you have the black fluid. You can refill the reservoir with clean fluid, but you really need to flush out all of the old fluid by bleeding the brakes until you get clean fluid. The only way to fix this for good is to replace the old rubber lines with braided stainless lines.

 

[mauivette]

I agree. I was having the same thing but in both reservoirs to some degree. Spent last Sat. installing Hawk brake pads, Stainless brake lines and emptying, cleaning and bleeding the brakes. Oh yeah, as long as I was doing it I installed those nifty self bleeding valves. Works like a charm and stops much better. I put a piece of clear aquarium hose over the bleeder valvle so that the fluid didn't shoot all over everything and pumped till the fluid ran clear. About every 7-8 pumps I checked the reservoir to make damn sure it didnt run dry so I would have to start all over again. It took about 6 hours for the entire job. Well worth the time and money.

 

[ErnieN85]

The fluid also gets darker when it absorbs water. it should be flushed once a year or just before a track session. the fluid attracts water so much that it will actually absorb water through the seals & hoses.

 

[Robertwav1]

Hey Mauivette,

How those auto bleeds work and where did you get them. I know they have the auto bleeder for the regular fittings that are on the car, but, I never seen the auto fittings. I'l like to do that next time around along with the braided hoses.

 

[mauivette]

The auto bleeders work fantastic. I wish I would have invented them. You just open them 1/2 a turn and stick the hose over them and into a pan or jar. I belive I got them from Mid america (Might have been corvette central). Turns a 2 person job into a 1 person job and ernieN85 is right, fluid should be changed real regular, espically here where humidity is high. This makes it doable by yourself. As to the braided stainless steel hoses, I never realized it but now that I think of it I guess that the 13 year old rubber hoses were expanding under all the pressure of braking. With the SS ones they can't expand so all that energy goes to the pistons on the calipers and I can definitely feel the difference. As for the brake pads, My old oves were glazed so I don't know how much difference the Hawk's make. I wanted a very good street pad since I don't track race and I feel I got that at a decent price. I would do it the same way again.

 

[XS650]

I removed all the dark/dirty fluid and there was some sludge at the bottom of the reservior. Once I got it all cleaned out I refilled it with clean fluid. Today I was under the hood again and noticed the front reservior was begning to get dirty again, but the rear one is still clean.

You have gotten some good advice about replacing the rubber hoses.

Something I have found out is that if you change the fluid in a cruddy system. brkes, clutch, power steering, whatever.... is that you often need to change the fluid again in a few weeks. Things seem to stay clean better the second time you bleed the system.