Brake fluid flush.

[mtsmiths]

Query to resolve a discussion on a non-automotive board (several Subaru owners there). How much of the push to flush ones brake system is real, and how much is wallet flush?

 

I understand that brake fluid is very hydroscopic and that it absorbs moisture from the atmoshpehre. But is the schedule realistic? It seems to me that every three years or so is enough in any environment, maybe far less often in very dry climates like AZ/NV/NM (or for the last few years Montana!).

[OB99W]

Without taking sides on the issue, I offer the following:

http://www.aa1car.com/library/bfluid.htm

[WAWalker]

The schedule is basicly every 3 years. 30 months (2.5 years) or 30k, which ever comes first.

 

So I would say the schedule is realistic.

 

Yes, brake fluid absorbes water. Water can cause corossion, and water in the brake fluid will also lower it's boiling temp.

 

You will get a lot of different opinions. Some like pay for scheduled maintanence, some perfer to react to failures (pay for repairs).

[nipper]

Its real but ...

 

Some mfgs say its never nedded. Some have a very short interval. Some people never flush them and are fine. Personally, I feel if its done at every brake service (pad/shoe replacement) you will be fine. Its not so much the interval, but the obscene amount of money the dealer wants to do the service that gets my goat. If you are doing it yourself, its like any other fluid change, do it as often as you like.

 

nipper

[schlit]

Query to resolve a discussion on a non-automotive board (several Subaru owners there). How much of the push to flush ones brake system is real, and how much is wallet flush?

 

I understand that brake fluid is very hydroscopic and that it absorbs moisture from the atmoshpehre. But is the schedule realistic? It seems to me that every three years or so is enough in any environment, maybe far less often in very dry climates like AZ/NV/NM (or for the last few years Montana!).

 

It needs to be changed to prevent problems later in the car's life. It's not one of those things that will fail your brake system at 50,000 mi if you dont change it, but it will corrode the lines and gum up the calipers eventually. Therefore, you will likely encounter a lot of people who dont change it because they just dont keep their cars past 125,000mi. If you're in for the long haul like me, three years is about right, maybe a little more often. I do my own flushes and typically it'll be very dark fluid w/ chunks coming out after about two years.

[Rooster2]

I flushed the brake fluid in my 2 Subies last summer. I bought both cars used, so prolly the fluid was the original in both. What pumped out was the color of ice tea. I didn't see any "chunks" or dirt, so maybe that was a good sign. I just feel better knowing that fresh fluid is in the system, and both brake pedals are rock hard.

[CNY_Dave]

Maybe I'll do this the easy way- turkey-baster out most of the fluid in the master cylinder, add fresh, then just open the bleeders one by one. In fact, maybe I'll push back all the calipers first.

 

Not sure about ABS equipped vehicles, but every other car I've owned if you just crack bleeders, fluid will flow and there's no tendency to suck air in.

 

You know, if you sucked the MC fluid pretty much out, retracted the calipers, sucked out the fluid again, then added fresh and pumped the brakes, you'd have at least 75-85% replacement.

 

Do it twice and you'd be at 90%+ I bet.

 

 

 

Actually, I just need to make sure the dealer did this as part of the 60K service they said they'd do before I bought the car.

 

 

Dave