Changing brake fluid for the first time -- questions

[Long Islander]

I'm going to take the plunge and change my brake fluid for the first time. I've read the instructions posted here and have a couple of questions.

1. Do I just loosen the bleeding screws with a metric socket wrench?

2. How long a bleed tube do I need, and what diameter (1/4", etc.)?

3. If I want to get someone to bleed the brakes using the brake pedal, at what stage do I do that? Any other tips?

Also, do I really need to even do this? My car is 5 years old, but with only 4,800 miles. The brake pressure feels very solid, and the brake fluid, visible through the brake reservoir look perfectly clear and amber.

Edited July 2, 2006 by Oggie (on L.I.)

[Ubermensch]

I'm going to take the plunge and change my brake fluid for the first time. I've read the instructions posted here and have a couple of questions.

1. Do I just loosen the bleeding screws with a metric socket wrench?

2. How long a bleed tube do I need, and what diameter (1/4", etc.)?

3. If I want to get someone to bleed the brakes using the brake pedal, at what stage do I do that? Any other tips?

Also, do I really need to even do this? My car is 5 years old, but with only 4,800 miles. The brake pressure feels very solid, and the brake fluid, visible through the brake reservoir look perfectly clear and amber.

1. A flare nut wrench is preferred to avoid rounding, but a standard wrench will work fine. You can't use a socket.

2. I'm not certain on the diameter, but the length is just a convenience issue. You want it long enough to reach into your drain container conveniently and not flip out and splash corrosive fluid on your or your paint.

3. This question makes me think you don't understand the process very well....if you're using a pressurized system (recommended by Porsche, e.g. motive) then you don't need to touch the brake pedal. If you're using the braking system itself to generate the pressure then your assistant will need to operate the pedal during the entire operation (press pedal, open bleed screw, close bleed screw, release pedal, repeat).

Brake fluid is hygroscopic and absorbs moisture as a function of time. The moisture deteriotes the performance and possibly the hardware of the braking system. The recommendend replacement interval is 2 years, so yes, you need to do it.

Shawn

Edited July 3, 2006 by Ubermensch

[Long Islander]

Shawn, many thanks.

My thinking was that if not changing the brake fluid just deteriorates my braking performance, I should be able to tell when that is, so I could put off the brake fluid change until then. On the other hand, if moisture in the brake fluid is likely to harm the braking system, then I should change now it despite my low mileage (since moisture will creep in based on time rather than mileage).

Any thoughts?

Edited July 3, 2006 by Oggie (on L.I.)

[Loren]

Yes, change it now and at least every two years going forward. If you track the car then plan on 2-3 times per year.

[Izzy]

Oggie,

I would recommend investing in a Motive power bleeder and waste bottle. Should run you about $45-$50. Then you can flush the brake fluid. There a few posts here on how to do it. I also switch colors between blue and gold, as a pokayoke on the flush.

The Motive container is simply filled with the brake fluid, then screwed onto the expansion tank, and pressurized. Then you can go through the fluid flushing one wheel at a time and be certain no air in the system and a good flush too.

[Long Islander]

I ordered the Motive power bleeder and some brake fluid. When I'm done, how do I dispose of the old brake fluid? Do I just flush it down the toilet?

[Izzy]

Only if you live in NJ you can do that. Nah, just kidding, lovely state, I lived once in Flemington.

No, it is very corrosive, take it to a recycling center for your county on the Island. As I remember in NJ, the town had a recycling center with large safe containers labeled for homeowners to dispose of motor oils and " other" corrosive liquids. Not sure what county you are in, but thougth Massapequa had one last time I was there.....

[djantlive]

Take it to an auto repair shop or gas station shops. Brake fluid is very hard to recycle / dispose. Motor oil is easy.