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Brake fluid change DIY with pictures

47K views 25 replies 14 participants last post by  nemohm 
#1 · (Edited by Moderator)
Brake fluid changed

I thought I didn't need to change brake fluid vehicle lifetime.
My 2007 SF 3.3L is 5 years old and 72,000km(45,000 miles) odo.




- vacuum bleeder from eBay $30 + shipping,named K Tool 72260.
I found this is the exact same product as Mityvac mv8000.


- Preston DOT4 brake fluid 946ml $13
- 10mm wrench
- baster $1 at dollar store (from Turkey baster kitchen kit)
it's optional, you can bleed more fluid from screw if you don't take old fluid from the reservoir
or just use vacuum bleeder
- grease or Teflon tape for bleeder screw's threads
- optional, jack & stand & tire removal
(I did not jack, not remove tires. I just crawl under)


1. open hood, remember current fluid level (to make it the same level when you finish job & top up fluid)
2. Open the reservoir cap,
Squeeze north and south corner of the red mesh and pull it out.





3. remove as much as possible old fluid with a baster / vacuum bleeder (about 200ml removed)


4. fill new fluid till max level.

5. Each caliper of rear right -> rear left -> front right -> front left
5-1. open the rubber cap of bleeder screw
5-2. put some grease on the screw threads (or pull the screw out and put 3 inches Teflon tape on the thread only. do not cover the side hole)



5-3. put 10mm wrench and vacuum hose attachment
Hyundai Forums : Hyundai Forum - sn20202020's Album: SF brake fluid - Picture

5-4. pump vacuum and turn the screw 1/4 ~ 3/4
5-5. bleed until new fluid comes out. (about 100~150ml)
5-6. Top up the reservoir to the max level

6. replace the red mesh into reservoir. Fill to the initial remembered fluid level. close the cap.


For the first try, I could only 100% air instead of old fluid, from 3 tires' bleeder screws.
That's because I did not put any grease on the screws, air went to the threads and returned to vacuum hose. So I had to do it again after apply grease. Yet

I found this vacuum bleeding is little tricky to figure out air leaks and apply grease.

I recommend TWO people bleeding, without the vacuum tool and grease.
It need only a jar and 2 feet clear hose.

Anyway, my old fluid looks so dark and browny.


I feel about 10~20% better braking.
Also I hear ABS working sound when I push brake pedal hard that I couldn't hear for long long time.
 
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#4 ·
Yeah I change fluid every time I change pads + rotors. Wheels are already off and calipers are easily accessible, and brake fluid is dirt cheap so one may as well do it all at once.

One thing I have seen but have yet to try are speed bleeders. They are bleeder screws with a check valve so one can drain out the fluid without a partner and with just the brake pedal, and no pump apparatus like the one here is required. I currently use a hand pump / vacuum like the one he used here, but I am going to put the speed bleeders on the next time I change fluid to try them out. They sound fantastic, does anyone have any experience with them?
 
#6 ·
Yes! Excellent write-up. Thanks for taking the time.

45K miles sure isn't much for a 2007, but that 5yr point is when stuff is going to need to be replaced.

You're lucky you didn't have more bleeder issues after 4-5 Ontario winters. Things were rusted up pretty badly on my 2008 when I recently replaced pads and rotors all the way around at ~70K miles. I didn't change fluid, but I gooped up the bleeders & bleeder boots with Sil-Glyde silicone grease.

Joel
 
#14 ·
The article talks about why brake fluid might need to be changed, not why it MUST be changed.

I loved this sentence: "Most automotive professionals agree that glycol-based brake fluid, (DOT 3, DOT 4, DOT 5.1) should be flushed, or changed, every 1–2 years." Yup - those are the same guys that will tell you that every severe duty interval applies to every customer they meet, too. Just like anti-freeze and engine oil, it really is possible to know WHEN changing this fluid is appropriate (see post above), and the vehicle, driving habits and mileage, and driving environments have far too many variables to ever make a broad statement about intervals in months or years... or really, even in miles.

It's a lot like the "change your oil every 3 months or 3,000 miles". Lord - if I park the thing in my garage and your oil oxidizes to the point of needing to be replaced in 3 months, you need to reconsider where you're getting your oil!
 
#13 ·
Actually it doesn't explain anything about mosture percentage and why you can test and change it when it needs it, at 3%-4% or above.

Who wrote this thing, ----a brake fluid , manufacter telling you to change fluid every 1-2 years. I have gone 6 years before moisture has even become high enough to measure and possibly justify changing. I would rather over change my transmission or engine oil; more possible up side.
 
#15 · (Edited)
The important 'Qualities' of Brake Fluid, written in 'Wikipedia', are.

"Brake fluid is subjected to very high temperatures, especially in the wheel cylinders of drum brakes and disk brake calipers. It must have a high boiling point to avoid vaporizing in the lines. This vaporization is a problem because vapor is compressible and negates hydraulic fluid transfer of braking force."

"Brake fluids are hygroscopic (water absorbing), which means they absorb moisture from the atmosphere under normal humidity levels."

This is why it MUST be changed at regular intervals, even if the vehicle is stationary. What price safety? and your families life if your brakes fail!

To prevent Manufacturers being sued through the courts they have to put Mileage/Time limits on 'Service intervals'. This is to negate the problem of the many 'Drivers' who have no comprehension of what happens under the bonnet/hood of a vehicle, these people would, if left to their own little world, never ever have their vehicles serviced then complain when they break down!!!

I could tell many horror stories of vehicles where the engine oil won't drain because it's too thick, low oil pressure due to there being no oil in the sump, brake fluid that's black with a high water content, spark plugs with no central electrode, induction pipes collapsed due to blocked air cleaners, diesel injectors long past their service life, frozen engines due to anti-freeze being many years old and diluted etc. etc. All of which could have been avoided if the vehicle had been serviced on time and in the correct manner!!

PS; I agree with the point on engine oil, it all depends on temperature and the number of cold starts.
 
#16 · (Edited)
To prevent Manufacturers being sued through the courts they have to put Mileage/Time limits on 'Service intervals'.
If Hyundai thought they would be sued if we didn't change out our brake fluid every 1~2 years, don't you think there would be at least some mention of a brake fluid change interval in their documentation? They don't. Neither do any other auto manufacturers that I've run across in my auto purchases.

The current quality of most of the fluids in a vehicle can be determined easily, and the others can be determined at less cost through a simple test than the cost to "flush" and replace them. THAT is the job of the customer and the service writer, not adhering mindlessly to some sort of schedule. BTW: I live in a very dry climate (high desert plateau) - we don't have quite the same issues - and that's the point.

The only group that promotes "unscheduled" fluid swaps are those writing the service orders, and they've got boat payments to make.
 
#17 · (Edited)
"I could tell many horror stories of vehicles where the engine oil won't drain because it's too thick, low oil pressure due to there being no oil in the sump, brake fluid that's black with a high water content, spark plugs with no central electrode, induction pipes collapsed due to blocked air cleaners, diesel injectors long past their service life, frozen engines due to anti-freeze being many years old and diluted etc. etc. All of which could have been avoided if the vehicle had been serviced on time and in the correct manner!!"

Your horror stories are about those who obviously don't even bother to inspect these things on a regular interval, and don't replace things when they need to be replaced! There's a VERY wide gap between that and replacing everything on an arbitrary fixed interval known only to the service writer, especially one not specifically recommended by the manufacturer!

For each of the failure modes you mention:

1) Engine oil - visual inspection will have prevented this. Testing is available.
2) Brake fluid - visual inspection will have prevented this. Testing is available.
3) Spark plugs - geez, just PULL one and see how they look!
4) Air cleaners - LOOK at the silly thing!
5) Bad injectors - there would be a major performance or mileage issue
6) Anti-freeze - testing tools available at WalMart

My point isn't that these things shouldn't be inspected at intervals frequent enough to cause problems. My point is that NONE of the items above are likely to fail and require replacement at some specific time or mileage interval in all climates and driving environments, and you can bet that the manufacturer is betting on the conservative side most of the time. The idea that every vehicle's brake fluid has absorbed enough water every 1 to 2 years to require replacement is false. Period.
 
#18 ·
"To prevent Manufacturers being sued through the courts they have to put Mileage/Time limits on 'Service intervals'. This is to negate the problem of the many 'Drivers' who have no comprehension of what happens under the bonnet/hood of a vehicle, these people would, if left to their own little world, never ever have their vehicles serviced then complain when they break down!!!"

This was the point I was making!
 
#19 · (Edited)
And the point I'm making is that FAR too often, service writers take it upon themselves to second guess the manufacturers' recommended service intervals (shorter ones and always to their own benefit, of course), or make up services that the manufacturer does not even recommend.

We've wandered a bit. The issue at hand here is specifically the so-called '"requirement"' to change brake fluid every 1~2 years. To that, I can only say -- Don't believe everything you read in a Wiki.

Tell me honestly -- do you suppose you have EVER met a service writer who would actually tell the shop to TEST the bloody brake fluid before recommending changing it out? Of course not. They really don't care. The tools are several and easy to find. Do you think they'd use it?

Two words: BOAT PAYMENT
 
#20 ·
And the point I'm making is that FAR too often, service writers take it upon themselves to second guess the manufacturers' recommended service intervals (shorter ones and always to their own benefit, of course), or make up services that the manufacturer does not even recommend.

We've wandered a bit. The issue at hand here is specifically the so-called '"requirement"' to change brake fluid every 1~2 years. To that, I can only say -- Don't believe everything you read in a Wiki.

Tell me honestly -- do you suppose you have EVER met a service writer who would actually tell the shop to TEST the bloody brake fluid before recommending changing it out? Of course not. They really don't care. The tools are several and easy to find. Do you think they'd use it?

Two words: BOAT PAYMENT
In my time I've worked for three major vehicle manufacturers in Service, Training and Sales. Your, so called, Service writers only write what they are told to write by the design engineers taking into account extensive test programs in all climate conditions, from the Artic through Desert to Tropical rain forest, and what the consumer product suppliers recommend.

Everything in Wikipedia on the subject of brake fluid is, in my opinion, correct. If you want I can post a document from an American site and an official USA Hyundai document stating brake fluid change intervals of 2 years. (This document is for a Lantra but would apply to other models)

Surely it's better to carry out preventive maintenance than wait for a failure.

I am, surprisingly, largely on your side! Your contributions are invaluable but I'm not sure what you mean by Boat Payments.

My whole 'argument' relates to the 'Tossers' who never service their vehicles.
 
#24 ·
I'm sorry about this going off piste a bit, it wasn't my intention.

I now see where the confusion regarding 'Service Writers' has come from, in my mind the 'Service writer' is a technical author employed by the manufacturer where as Canderson is referring to what I would call a 'Service receptionist'. (With this in mind I agree with a lot that he says) Our problem is a great language divided by a big pool of water!

I apologize again and with that I'll shut up!!
 
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