I'm getting read to do my 30K service. Most of which i will do myself. I see that Subaru is calling for a complete brake fluid change (which seems pretty excessive to this old car jockey.) Still, I'm new to the brand and wonder if this is something I really should be doing . ( My guess is it will be a $100+ note at the stealer.) Is anybody else doing this? What are the potential consequences if it's not done? Any experience appreciated.
30,000 mile service - is a brake fluid flush really necessary?
RocketMan20
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I bought this with skepticism as a cheap tool providing interesting results. https://www.amazon.com/gp/product/B076SC377J/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I found it odd had almost 5 stars so I had to check it out. My OB with 16k miles came back perfectly green, 0%, I had never opened the brake fluid until that moment. My GF's Ridgeline which just had a dealer brakeflush, 3%! I went to Autozone and tested
a cup of freshly opened Autozone brand dot3, 2%. I took the truck back to the dealership to explain my findings and would they be willing to test a couple brand new cars with me? They straight up just did
another flush without any testing. Came back 2%. I know Subaru puts out quality lubes, coolant ,etc. but I'm still testing to find another perfect 0%.
That's why conductivity testers are unreliable
Thanks much for the input. I guess I'm getting schooled here. I've been driving for 50 years now and NEVER completely flushed a brake system unless I had catastrophic loss of fluid/ and component changes. I've also have very few failures of calipers and such due to corrosion (and those were on vehicles that got backed into the ocean to launch boats.) . To be honest, I've never even heard of flushing the brakes as routine maintenance. That said, I know systems are more complex these days and likely made of cheaper materials so I won't ignore the 3-5 year rule I'm hearing repeatedly here. I'm at 31K mi but still 6 mos short of 3 years. I don't live in a super humid environment and the car is garaged so I think I'll just hold off and have my tire dealer do a flush when he puts on my new tires this fall.
Another data point, my wife's 2001 Avalon which we bought new, has never had anything done to the brake fluid. Just pads replaced, still original calipers and disks. It does have anti-lock brakes, they still work fine.
I'm afraid to flush it now, the brake lines go into the caliper/cylinder in one place and the bleeder is in another place, so if I flush it, all the goop in the lines is going to fall out in the wheel cylinders before it gets to the bleeder outlet, lol.
I'm afraid to flush it now, the brake lines go into the caliper/cylinder in one place and the bleeder is in another place, so if I flush it, all the goop in the lines is going to fall out in the wheel cylinders before it gets to the bleeder outlet, lol.
That's odd, the have not touched the brake fluid on my wife's 2018 Crosstrek, and she takes it in for everything because it's free. Guess I should test the fluid myself and see what's what.
I purchased a brake fluid moisture meter years ago from Amazon. I periodically check the fluid moisture content. 36,000 miles on my Ascent with no significant moisture. Thirteen year old Mazda Miata with no moisture. All with original brake fluid. I'm not going to replace it until I get moisture in it.
On my older cars must confess I have neglected brake fluid changes - the only time ABS engages is once every 5 years. But in new cars with brake based torque vectoring the braking system is constantly active and if it gets mucked up I'm afraid the consequences are worse.
)Under warranty, follow Subaru's guidelines
Brake fluid should be charged every 3 yrs regardless of mileage. It's a good idea to have your brakes annually in any case.
Tires: Change at 5-6 years or 5/32 (snowy areas) or 4/32 (other areas)
Oil, is mileage/operating hour dependent, not time. Oil on Gen6 Outbacks typically needs to be changed more often due to fuel in the oil, common with DI engines. Have your oil analyzed to see if it a problem for your specific driving conditions.
Other fluids and spark plugs are mostly mileage/operating hour dependent.
Belts/batteries are dependent on mileage/operating hours and time
Hoses and plastic/rubber parts and brake lines, mostly time, and conditions.
Brake fluid should be charged every 3 yrs regardless of mileage. It's a good idea to have your brakes annually in any case.
Tires: Change at 5-6 years or 5/32 (snowy areas) or 4/32 (other areas)
Oil, is mileage/operating hour dependent, not time. Oil on Gen6 Outbacks typically needs to be changed more often due to fuel in the oil, common with DI engines. Have your oil analyzed to see if it a problem for your specific driving conditions.
Other fluids and spark plugs are mostly mileage/operating hour dependent.
Belts/batteries are dependent on mileage/operating hours and time
Hoses and plastic/rubber parts and brake lines, mostly time, and conditions.
Owning an auto shop you're my favorite type of expert. I get bigger tickets and more 'have to have done now' work from customers who listen to folks like you. Please, keep on doing what you're doing.
For those of you who don't think auto repair shops are ALL out to get you...My advice? Find a shop that is a BG dealer for fluid flushes. BG subsidizes warranties on all lubricated parts that you flush/service with their products with a two tier plan. 50k and under and 100k and under. Flush the brake system at 49k and if you have a master cylinder fail in the next 30k you'll have up to $2k to cover the replacement. Same goes for GDI engines, differentials, CVT's, Power Steering, Coolant, Transfer Cases. That's how confident BG is in their services/products and I fully endorse them. I sell a lot of flush services out of my shop because I believe in them and their best in class chemistry. My family drives vehicles that are ALL seven to twelve years old - all of them flushed/maintained and they all have zero problems in their systems covered by BG maintenance. (And if anyone cares - run a GDI service every year or 12k. Don't wait until your spark plug interval service arrives. You'll thank me later. Every GDI car is prone to carbon buildup from this injection process on the valves.)
That tool is no better than using a Digital Multi-Meter, set to the lowest voltage setting. You put the Black lead against the battery ground, and dip the Red terminal into the fluid. If it isn't <.3 volts (3 micro-volts), there's too much moisture in the system. - Probably more accurate than using the AA/AAA cell between two terminals, however, I'd still change the fluid every 30k as recommended.
If your driving is really low, think about changing it between 3-4 years, since fluid is cheap, and replacing lines, calipers, or worse a master cylinder/ABS pump is rather expensive.
If your driving is really low, think about changing it between 3-4 years, since fluid is cheap, and replacing lines, calipers, or worse a master cylinder/ABS pump is rather expensive.
No no NO!!! (Not for the brake fluid)
Changing the fluid in the master-cylinder does nothing for the rest of the brake-system. The same old crappy fluid will remain in the piping, ABS unit, and calipers.
Lets not forget that the brake fluid DOES NOT circulate. It moves no more than 1/2 inch back and forth as the brakes are used.
Infact, the condition of the brake fluid in the MC (even if tested)... does not tell you condition of the rest of the system.
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With that said, perhaps you are thinking of a hydraulic Power-steering system. (Which does circulate). In this case, one could suck out from the reservoir and put in new. This would replace about 1/4 of the total displacement of fluid.
If this was done every couple weeks... after about 6 changes, there would be over 80% new fluid in the system. The math to calculate how much old fluid is removed each time tells us that one would be replacing less of the old fluid each time. (because of mixing) The math also tells us it is IMPOSSIBLE to change all the fluid by doing partial changes.
what is a BG Dealer?
there are many differing opinions in the auto tech world regarding the value of using BG flushes. All of these are typically strongly held.
A manufacturer dealer will either simply change the fluid via drain and replace or they can perform a flush which uses a pressurized system to push through a fluid. For an oil change the manufacturer dealers will use oil to push through. A BG service will use the BG product to flush out the old fluid and then they can fill with the proper fluid such as the motor oil.
BG brake flush
BG has an excellent reputation for the BG 44k product widely used in gas to clean port fuel injection systems - that can work like a miracle with first hand experience. I know they have a lot of other products but I have not used those - never heard of any of their products being bad, but just because a company makes a fantastic product doesn't mean each and every of their products are equally fantastic. I would hesitate to use a brake system "flush" aside from brake fluid itself, unless there was something seriously wrong with the brake system and it needed something special to "clean it out" but for routine maintenance I would not use BG 44k or any BG product - I think it's best used as a problem solver not as a preventative.
BG would suggest otherwise, although I do not think they intend it to be used at regular oil changes, but rather at greater intervals of maybe 3 years. they basically suggest that in all cases it will improve stopping power and avoid (not always present) the moisture buildup that can mess with the calipers etc. It makes sense to me, but whether the added value is sufficient to justify at any particular time is an individual choice. I have not decided for myself.
Since I've never used it my opinion is based just on the general idea that if it ain't broke don't fix it. If you let your brake fluid go for 9 years yeah maybe you need something extra for your flush, but if you change it every 2-3-4 years it's probably unnecessary. Pure speculation on my part, but BG naturally wants you to use their products whether you need them or not, as long as it does no harm.
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