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brake fluid

  • Bikers usually talk about performance and aesthetic upgrades.

  • But how many actually talk about brakes and brake maintenance?

  • Today, we look at how often should replace the brake fluid.

It surprises me that in my 33 years of riding, no one had ever asked, “How often should I replace my brake fluid?”

I’ve always been asked what’s the best performance parts such as exhausts and tyres, instead. It’s not wrong to ask about those parts, of course, but brakes are the most critical next to the almost everything else on the bike.

However, I do understand why almost nobody talks about brakes. Modern brake systems are very reliable. Apart from replacing the brake pads whenever they’re worn, the system keeps working: The rider presses the lever and the bike slows down. When the pads are worn again, he replaces them.

In a brake system that performs normally, performance deteriorates slowly and surreptitiously. Consequently, you won’t feel much difference since the last time you rode it. This will continue until we encounter serious problems.

But what about the fluid? Sadly, no one seems to bother. Brakes are working after all. News is, deposits will start to build up in old brake fluid. If you’re unlucky, these deposits may someday flow into the nooks and crannies and block the flow of fluid in the system. In the worst-case scenario, deposits build up or get into the ABS pump and render it useless. When this happens, the part must be replaced, which costs thousands. Believe me, I’ve seen this happen in both bikes and cars.

Old vs new brake fluid

Besides that, brake fluid is hydroscopic i.e. attracts moisture. The system may be sealed but wear and tear can eat away at a gasket or two. The presence of moisture in will lower the brake fluid’s boiling point. When this happens, the brake takes more effort to work. In a bad scenario, the brake lever will feel spongy. In the worst case, the lever has been pulled all the way back and sticking to the handlebar, yet the bike doesn’t slow down at all.

So, how often do you need to change your brake fluid? Every two years, regardless if the fluid “still looks good.” The job is easy enough that you could DIY (do-it-yourself), but you can also visit a workshop if you aren’t confident or need more tools.

What DOT should I use? Just follow the manufacturer’s recommendations. For example, use DOT 4 if that’s recommended. Try not to be seduced by the mechanic’s “Ini barang baik punya (This stuff is good)” sales pitch, especially if the fluid is of different DOT rating or for racing. Racing brake fluids are usually even more hydroscopic!

  • A man used brake fluid to alleviate toothache.

  • It caused swelling, pus build-up and more pain.

  • In the end, the pus spread to his nervous system and brain.

There are many dos in motorcycling, and just as many do nots. This case, however, went beyond the do nots and straight into the OMG zone. It happened when a man in Kuala Terengganu used brake fluid to cure his toothache.

Before continuing further, we would like to state that the patient approved the original post by a healthcare worker.

It was learned that the patient suffered toothaches for a number of years before it worsened a year ago. He then applied brake fluid to the tooth in hopes of alleviating the pain. It actually subsided during that point in time.

A few weeks later, a molar (large tooth at the back of the mouth) on the upper jaw started hurt. Again, he applied brake fluid to it. Alas it didn’t work this time and his gums started to swell, instead.

However, he visited a physician instead of a dentist. The doctor prescribed painkillers and antibiotics. The antibiotics didn’t work, and he suffered more pain for another four days before visiting a dentist.

According to the post, his head had swollen to the size of two heads by that point. It’s called facial cellulitis. The dentist referred the case to the emergency department at the Hospital Raja Perempuan Zainab II in Kelantan where he was warded immediately.

The swell grew even bigger by the second day of his stay due to the build-up of pus. The medical decided to extract the tooth and carry out an incision to remove the pus inside his face (thus the large hole). It was described as “too much pus” in the post.

One the next day, they found that the pus had spread to the patient’s nervous system and brain. The case was then referred to the ICU and diagnosed as septic encephalopathy (functions of the brain is affected by toxins in the blood).

They sent him to the operation theatre in another attempt to drain the pus.

Thankfully, his condition improved after a week in ICU and was sent back to the normal ward.

It’s a good lesson that everyone should remember. Brake fluid is caustic enough to remove paint, so one could imagine how it affects living tissue!

Source and pictures: kulihatlangitbiru.com

  • Harley-Davidson Motor Company, Inc. telah memulakan satu Kempen Panggilan Semula Keselamatan bagi menggantikan bendalir brek yang lama bagi sesetengah model.
  • Model-model yang terlibat adalah model Touring, CVO Touring dan V-Rod dengan ABS dari tahun 2008 hingga 2011.
  • Kedai pengedar rasmi Harley-Davidson terbaru di Malaysia, Harley-Davidson Petaling Jaya, akan mengendalikan kempen ini di tanah air kita.

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  • Harley-Davidson Motor Company, Inc. has initiated a Safety Recall Campaign to replace the old brake fluid of certain models.

  • The models involved are 2008 TO 2011 TOURING, CVO TOURING AND V-ROD MODELS WITH ABS.

  • The new Malaysian Harley-Davidson dealership, Harley-Davidson of Petaling Jaya will carry out the campaign.

The Harley-Davidson Motor Company, Inc. is conducting a Safety Recall Campaign for its motorcycles worldwide.

In an earlier article of ours, we mentioned that the motorcycle’s brake fluid needs to be replaced every 2 years, regardless of mileage and appearance.

This is because brake fluid is hygroscopic (a description for something that loves moisture) and will absorb moisture right out of the air. It is even more critical in our country where the climate is hot and humid. Moisture in the fluid will lower the latter’s boiling point, causing brake fade.

Old vs new brake fluid

As for this Safety Recall Campaign, the models involved are 2008 TO 2011 TOURING, CVO TOURING AND V-ROD MODELS WITH ABS.

The Motor Company notes that the brake fluid should be flushed and replaced with fresh fluid every two years, as per the H-D Owner’s Manual and Service Manual. Prolonged usage of the old fluid may cause it to gel and leave deposits on the brake components. Should these deposits continue to form over a prolonged period on the apply valve of the ABS Hydraulic Control unit, the valve may stick and cause a loss of braking function.

The new Harley-Davidson dealership in Malaysia, Harley-Davidson of Petaling Jaya (HDPJ), will carry out the campaign for all the affected motorcycles, regardless if they were purchased through the official channel or grey importers. And there is also good news for owners of grey import Harley-Davidson’s, as the new dealer no longer charges an exorbitant “activation fee” for the technician to simply work on your bike. All Harley-Davidson’s are now welcome at HDPJ regardless of where you bought your bike.

Harley-Davidson of Petaling Jaya is located at The Gasket Alley

As such, the Motor Company will communicate the affected VIN (vehicle identification number) to HDPJ. However, as HDPJ is still new and there are many grey import Harleys in Malaysia, owners of 2008 TO 2011 TOURING, CVO TOURING AND V-ROD MODELS WITH ABS are advised to contact HDPJ and provide their VIN for verification. HDPJ will immediately confirm if the motorcycle if affected.

The new Harley-Davidson Platinum Label DOT 4 brake fluid will be available for ordering from mid-March 2018, thus HDPJ will schedule appointments for the affected units.

Only the replacement of brake fluid is covered and no further parts will be replaced under the campaign. Replacement of the brake fluid will be carried out using the Digital Tech II apparatus, as the bikes are equipped with ABS. Please be advised that the machine will instruct the ABS hydraulic control unit to fully flush the brake fluid and residue, hence replacement of brake fluid without the Digital Tech II machine is erroneous and potentially dangerous.

The task will take 1.5 hours and is free-of-charge.

Please get in touch with Harley-Davidson of Petaling Jaya at +603-79559399. You may also call Service Advisors Lingesh at +6018-9861229, or Naqid at +6018-9891229. HDPJ are open from 9.30am to 7.00pm Mondays to Saturdays and, closed on Sundays and Public Holidays. Please click here to visit the Harley-Davidson of Petaling Jaya’s FB page.

Also, as a side note to parallel importers who import Harley-Davidson’s, the official dealer at Harley-Davidson Petaling Jaya will also conduct software updates and bike resetting to prepare the motorcycle for local sale. While importers had to previously fork out money to previous H-D technicians to conduct “localization” and resetting, the official dealer can and will reprogram the bike for you with all the right tools and machines needed to service the bike. This is great news for grey importers as they can now have their machines better prepared for sale, while buyer’s can now rest easy knowing that their machines have been worked on by official Harley-Davidson technicians.

According to Juan Chow Wee, who is the General Manager of Didi Resources Sdn Bhd, the importer and distributor of Harley-Davidson in Malaysia, the new Harley-Davidson of Petaling Jaya is opening its doors to all owners of Harley-Davidson regardless of whether it was bought through the official channel or through the grey market.

“We want to be accessible to all Harley-Davidson riders, and we will not practise two standards. The love for Harley-Davidson runs in everyone working for Harley-Davidson of Petaling Jaya and we are showing this by not charging any localisation fee for any Harley-Davidson bike. The price of bikes, parts, accessories and merchandise has also been adjusted to ensure competitiveness, and we are proud to continue the Harley-Davidson brotherhood which was recently put on display at the Grand Opening ride and party.”

  • Pengoperasian sistem brek hidraulik cukup mudah untuk difahami.
  • Ianya terdiri daripada beberapa bahagian utama.
  • Walau bagaimana pun, berikan perhatian kepada bendalir serta hos brek anda.

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  • The hydraulic brake system’s operation is easy to understand.

  • It consists of only a few main parts.

  • However, pay attention to your brake fluid and hoses.

Everytime we squeeze and press down on the brake levers, the brake system causes the motorcycle to slow down. it works day in, day out, throughout the bike’s lifespan. But have you ever thought about how it actually works?

While the traditional cable-operated drum brakes are available on a certain number of bikes, they are being phased out for the hydraulic brake system, more commonly called disc brake system.

The brake system converts kinetic energy (contained in a moving object) to thermal energy (heat) by using friction. Brakes have evolved over time and some brake systems could actually slow a bike quicker than the latter could accelerate. In a recent overseas test on the BMW S 1000 XR, the bike accelerated from 0 to 160 km/h in 6.1 seconds, covering 151 metres. That fast! But it slowed from 160 to 0 km/h in 5 seconds in less than 100 metres.

The basic working principles of the hydraulic disc brake system is easy to understand. When you press the brake lever, the master cylinder pump pushes the brake fluid through the brake hoses to the calipers. In turn, this pressure pushes on the caliper’s pistons which have brake pads attached to them. The pads are compressed on to the brake disc.

Let’s look at the parts of a hydraulic brake system:

Master cylinder

More commonly called the “brake pump” or (“bulek pom” by your typical Chinese mechanic at the kedai motor), it converts mechanical force (when you press the lever) into hydraulic pressure. The brake lever pushes on a piston that presses on the brake fluid. The force with which you pull the lever is the leverage ratio and the size of the master cylinder piston determine the amount of pressure is subjected through the system, sometimes exceeding 1,000 kPa.

Brake Hoses

Hoses transmit pressure from the master cylinder to the calipers. They are typically multilayered, with a Teflon inner lining surrounded by braided nylon, or Kevlar, or stainless-steel reinforcing layer, and finally wrapped in a protective sheathing.

Contrary to popular belief, stainless steel-braided hoses DO NOT stronger braking. They provide a more consistent braking feel as they don’t expand like rubber hoses do when subjected to eyeball-popping hard braking.

Rubber hoses lose their strength over time, thus need to be replaced every four years.

Brake caliper

This is also inexplicably called the bulek pom in the workshops. The real job of pumping braking fluid is handled by the master cylinder.

Anyway, it’s at the caliper where the hydraulic pressure is multiplied. This is because the pressure from the master cylinder is exerted uniformly on the much larger area of the caliper pistons. An adult male’s hand grip typically exerts only between 0.4 to 0.6 kPa, thus that has to be increased to more than 1,000 kPa.

Brake Disc

The disc transfers the brake pads’ resistance to the tyre contact patch. Brake discs are usually made of stainless steel with variable amounts of iron. Modern discs are also drilled to assist in cooling, besides shedding water and debris.

Brake fluid

Another incorrectly named item, usually called minyak brek (brake oil). It has nothing to do with oils. The misconception probably arose from being referred to industrial hydraulic fluids that are petroleum based.

The brake fluid is the medium which transmits force from the brake lever to the brake pads. The brake fluid isn’t as simple as one may be inclined to think. Other than being non-compressible to effectively transfer the pressure, it needs to have low viscosity to work with ABS components, has good lubricity for the master cylinder and caliper piston seals, offer corrosion resistance, and importantly has high boiling point.

There are four grades of brake fluids. Glycol-based ones are DOT 3, 4, and 5.1, hence are mixable. DOT 5 is silicone-based and can’t be mixed any other type.

The glycol-based fluids are hydrophilic, meaning they suck in and absorb moisture from the air. Mixed with water, the brake fluid’s boiling point is lowered, causing brake fade. That’s why brake fluids need to replaced every two years.

DOT 5 on the other hand, is hydrophobic and rejects water. However, after repeated heating and cooling cycles, bad master cylinder and caliper seals, it will also ingest water eventually. However, DOT 5 brake fluid does not pull moisture out of the air own its own, thus have a longer lifespan. Military vehicles usually use DOT 5 since they sit idle for long periods of time.

Additionally, being silicone-based, it’s not caustic leading Harley-Davidson to using this previously.

Does this mean we should all convert to DOT 5? The short answer is “NO.” DOT 5 brake fluids are expensive, has high compressibility and higher viscosity (thicker) and thereby unsuitable for everyday use. Harley-Davdison has since reverted to DOT 4.

Each grade usually denotes the fluid’s boiling point, from the heat resulting from friction, rather than its chemical contents.

The US Department of Transport (DOT) specified each grade’s “dry” and “wet” boiling point. The latter is deemed to be completely free of moisture, while the latter contains 3.7% water, common after a year of regular use.

DOT 3: 205 oC (dry), 140 oC (wet).
DOT 4: 230 oC (dry), 155 oC (wet).
DOT 5: 260 oC (dry), 180 oC (wet).
DOT 5.1: 260 oC (dry), 180 oC (wet).

Observe how much performance drops away between dry and wet. That’s why brake fluid should be replaced every two years. Since the standard was set in the USA, we may need to replace it even earlier due to our climate’s high humidity and constant rain.

Water in the fluid lowers its boiling point, casing the brake lever to feel spongy and reducing braking performance – called “brake fade.”

That’s it for Part 1. We’ll talk about brake pads, caliper mounts, ABS, carbon brakes and so forth next time.

A quick guide towards upgrading your brakes for better control.

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