Civicnoobie

Even though when i press and release the pedal the rear brakes engage and release fine, but i need to double check the condition on my rear hoses that go from my brake pedal to the rear brakes. I was told they can go bad with age.

And whats the best way to lube it up?

maxtierney

iTrader: (5)

The only brake hoses are from the banjo fittings to the drums. About 18" worth. Everything else is hard line from the ABS modulator. Basically, it's a mechanical linkage from the brake pedal to the Master Cylinder/Reservoir. Just with any hose, whether it is a garden, beer bong, radiator or brake hose you will look for deformations, leaking or cracking. With a brake hose, typically it when your pedal goes to the floor that you'll know you've got a bad hose. I've only had one hose go bad on me EVER. Rubber brake hoses are less likely to blow than braided hoses, because you can actually see the rubber. Braided hoses give you no indications. As often as you see the mechanic, you'll know if you have a bad hose. Or if you do your own brakes, inspect them then.

Civicnoobie

Thanks. Can you see the braided hose and rubber hose from under the car? So if one is bad its most likely the braided one?

gearbox

iTrader: (95)

my rubber hoses look beat up. like uber hard and crusty. i dont think i saw any cracks tho.

Civicnoobie

where exactly are the rubber hoses? can i see it from under the car?

sdaidoji

iTrader: (1)

mine are almost decade old, still looking fine after the canada year and a half.
why do you want to check them?

Civicnoobie

Just want to make sure theyre still good.

Sometimes ill brake, release the pedal or hold it slightly then ill feel a slight jolt as my car moves forward a bit. Its noticable cause ill end up looking behind thinking someone hit me lol. So im wondering if my hoses could be clogged ior but corroded nside

Civicnoobie

My mech said that if it was the brake line it would cause yhe brake pedal to feel looser and hit the floor. True or false?

green01civic

If you're terribly concerned, go ahead and replace the brake hoses all around, and change/bleed your brake fluid with some fresh DOT-4. Go ahead and inspect thickness of rotors, pads, drums and shoes while you're down there. Should cost you about $90 for hoses and fluid, a small price to pay for peace of mind.

Civicnoobie

I thought our cars is dot 3 brake fluid? I just flushed my brake fluid last fall. My mech doesnt think its the brake hoses causing my rear drum auto ajusters to push the shoes out too far.

We already replaced one of the auto adjusters and it didnt do anything.

gearbox

iTrader: (95)

+1 just replace the hoses if youre not sure. there is no way to inspect them except by looking and even then it only tells you what the outside is like. if there is any leak, your brakes would not be working.

green01civic

DOT 4 is rated for use in a DOT 3 application. It has a similar composition, but has a higher boiling point (and higher "wet" boiling point, since brake fluid absorbs water over time, which degrades performance). I usually use DOT 4 fluid because it's better stuff, and it isn't much more expensive.

I am not saying your lines are bad, but if you have any reason to question their safety or performance, why not just go ahead and replace them.

maxtierney

iTrader: (5)

+1 on the DOT 4. You can pick up a liter of ATE Super Racing Blue or the Amber Type 200 for around $10 US. Comes in a metal can, which is supossedly better for keeeping moisture out. Best fluid for the money, period. There are better DOT 4s, but not for $10.

Dry Boiling Point of 536F
Wet Boiling Point of 396F

maxtierney

iTrader: (5)

Brake Fluids (I got this info from way back when I was interedted in brakes, still applies today)
--------------------------------------------------------------------------------
Lets look at what the DOT ratings mean. The table below shows the MINIMUM wet and dry boiling points for DOT 2, 3, 4, and 5 brake fluid in degrees fahrenheit.

Dry Boiling point/Wet boiling point

DOT 2 - 374
DOT 3 - 401 / 284
DOT 4 - 446 / 311
DOT 5 - 500 / 356

The DOT 2 spec is for drum brakes and is obsolete. If you have any DOT 2 in your garage, throw it away! DOT 5 is for silicone brake fluid. Silicone brake fluid (DOT 5) should be avoided because it is not compatible with regular brake fluid, it is hard to pour without introducing bubbles and thus results in soft pedal feel, and moisture still gets into your system and will pool in low areas like your calipers and encourage rapid corrosion. STAY AWAY!

That leaves DOT 3 and DOT 4 fluids. These fluids are compatible with each other and may be interchanged or mixed with no ill effects.

Let's look at some popular brake fluids and their boiling points:

Fluid (DRY / WET)

Castrol LMA DOT 3/4 - 446 / 311
Ford Heavy Duty DOT 3 - 550 / 290
ATE Super Blue Racing - 536 / 392
ATE TYP 200 - 536 / 392
Motul Racing - 600 / 421
Castrol SRF - 590 / 518
Performance Friction - 550 / 284


Castrol LMA is very good at rejecting moisture and may be kept in your brake system for a couple years. The LMA stands for "Low Moisture Activity". This is the minimum quality stuff that I would use in my Civic. It comes in plastic containers which do not have a long shelf life. Don't buy lots of this stuff at a time because moisture can make its way through the plastic containers.

Ford Heavy Duty DOT 3 is VERY inexpensive and is popular among racers because of its excellent dry boiling point. It absorbs moisture quickly, but the racers don't care since they change their fluid frequently. Comes in metal cans so it may be stored.

ATE Super Blue Racing and ATE TYP 200 are the same brake fluid in two different colors (blue and amber, respectively). BMW recommends this brake fluid for their street cars because it, like Castrol LMA, absorbs moisture very slowly. The advantage over LMA is that ATE has a much better wet boiling point. You can put this stuff in your car and forget about it for a long time. An excellent choice for a weekend track car which also sees regular street duty. Comes in metal cans. This is what I use in all of my cars.

Motul Racing 600 is a very exotic and expensive synthetic fluid with high wet and dry boiling points. Used almost exclusively in race cars. Too expensive for the street and requires frequent changing due to its hygroscopic nature. Sold in plastic bottles. It is not suitable for the street because it absorbs moisture quickly.

Castrol SRF is a hyper-exotic and hyper-expensive brake fluid that is generally used by wealthy Porsche owners at track events. I've seen prices of $78 per liter for this stuff. Sold in metal cans. I can't afford this stuff!

Performance Friction High Performance DOT 3 has a good dry boiling point but a crummy wet boiling point. It comes in metal cans which is good for shelf life and sells for $7.87 per 16 ounce container. If you are even considering this fluid, I would go with the cheaper Ford Heavy Duty DOT 3. In either case, change this fluid frequently due to the poor wet boiling point.


The amount of moisture in brake fluid definitely affects its performance. The big problem is it is absorbs moisture quickly. Over a relatively short period of time brake fluid will absorb moisture from the air. SAE field tests have shown that the average one year old car has 2% moisture in the fluid. A random test of vehicles in the U.S. showed an average water content of 2.6% for vehicles with an average age of 8 years. And 25% of these vehicles had water content greater than 4%.

As water content in brake fluid increases over time, the boiling point decreases. Fluid with a reduced boiling point (or high water content) can create vapor by boiling in the caliper, or wheel cylinder. The result is sudden brake failure. And water in the brake fluid can contribute to corrosion of parts such as steel pistons and ABS modulators.

The end result is even though DOT 3 fluid is "rated" at greater than 401oF, in the typical 3 to 4 year old car with 3 to 4% moisture content, it could boil under 300oF. And if it has got more than 4% moisture, you may as well be running straight water!

gearbox

iTrader: (95)

really good post. i still cant believe how many people dont change the fluid every 2-3 yrs. many people ive asked do not even know it needs changing. some are going on 10 yrs. your funeral i guess lol