Questions concerning the linked braking system.

MDO · Nov 30, 2017

I have a question regarding the linked braking system on our Freewheelers (mine is a 2017).

There is a sticky posted at the beginning & it states there is a special procedure for bleeding the linked brake system, but never states what the procedure is or provides a link to it.

Does anyone have that procedure?

I tired to PM the member who started the thread, Bill G, but I can't PM him.

Thanks

Jack Klarich · Nov 30, 2017

Without ABS

Keep the master cylinders near full

Start at the RR

LR

RF

LF

shake th hoses this will work out air bubbles

You can also pump up the front brake, use a bungy round the lever to the grip, let it sit for a few minues

slowly crack the front bleeders

this will work good with out having to continue to pump the handle

With ABS it is way different

A scanner must be used to energise the ABS module so it opens ALL the fluid ports

MDO · Nov 30, 2017

Jack Klarich said:
Without ABS

Keep the master cylinders near full

Start at the RR

LR

RF

LF

shake th hoses this will work out air bubbles

You can also pump up the front brake, use a bungy round the lever to the grip, let it sit for a few minues

slowly crack the front bleeders

this will work good with out having to continue to pump the handle

With ABS it is way different

A scanner must be used to energise the ABS module so it opens ALL the fluid ports

Thanks Jack. That seems fairly routine.

Jack Klarich · Nov 30, 2017

There is 1 exception I can think of

If calipers have multiple bleeder screws ( many imports do)

The caliper halfs need to be bled also

Air will always rise over the fluid

1 more reason most bleedersare at or near the top of a hydraulic unit

The MOCO has clearly detalied the fluid NEEDS to be changed every 2 years

This has been an on going routine maintanance for brake system for years

The reason being brake fluid ( often neglected) til there is a problem

DOES break down

The steel lines also contribute to this

As the lines give off some of a chemical reaction with the fluid

Also thru the heat cycles of braking the fluid does heat up and break down over time

Ever smelled really old brake fluid?

To me it smells like cheap whiskey

MDO · Nov 30, 2017

Jack Klarich said:
There is 1 exception I can think of

If calipers have multiple bleeder screws ( many imports do)

The caliper halfs need to be bled also

Air will always rise over the fluid

1 more reason most bleedersare at or near the top of a hydraulic unit

The MOCO has clearly detalied the fluid NEEDS to be changed every 2 years

This has been an on going routine maintanance for brake system for years

The reason being brake fluid ( often neglected) til there is a problem

DOES break down

The steel lines also contribute to this

As the lines give off some of a chemical reaction with the fluid

Also thru the heat cycles of braking the fluid does heat up and break down over time

Ever smelled really old brake fluid?

To me it smells like cheap whiskey

Thanks for the info. 1 more question, do you know anyone that has switched to DOT 5 fluid?

Jack Klarich · Nov 30, 2017

MDO said:
Thanks for the info. 1 more question, do you know anyone that has switched to DOT 5 fluid?

Nope, do not do it

HD has seen the errors of their ways with dot5

It will (over time and climate) crystalise in the cylinders

I had the displeasure on my 1997 FLHT bought new in 97, here in FLA 1 year later both master cylinders failed

I have NEVER liked dot5

ALSO it does NOT play ( mix) with dot 3 or 4

IMO use a fresh bottle of brake fluid

I buy as small a bottle as I need

Once you open it the clock is ticking

By that I mean it is a hygroscopic fluid, once you let the genie out it starts treding water

Flush your brakes every 2 years

Toss the little fluid you have left or top of your car with it

I never keep a bottle that has been opened for long

MDO · Nov 30, 2017

Jack Klarich said:
Nope, do not do it

HD has seen the errors of their ways with dot5

It will (over time and climate) crystalise in the cylinders

I had the displeasure on my 1997 FLHT bought new in 97, here in FLA 1 year later both master cylinders failed

I have NEVER liked dot5

ALSO it does NOT play ( mix) with dot 3 or 4

IMO use a fresh bottle of brake fluid

I buy as small a bottle as I need

Once you open it the clock is ticking

By that I mean it is a hygroscopic fluid, once you let the genie out it starts treding water

Flush your brakes every 2 years

Toss the little fluid you have left or top of your car with it

I never keep a bottle that has been opened for long

Thanks for the info. That's good to know. I will stick with DOT4.

ultrafxr · Nov 30, 2017

Good info. A little background on what I learned over the years about brake fluid. Dot 5 is silicone based but the reason is that when the spec came out only the silicone fluid could meet it. Being silicone based was not a requirement but that is what transpired. Like Jack said H-D used silicone based Dot 5 for a few years and from my experience it was a failure. My '99 ultra would lose its rear brake any time I was riding in the mountains. I'd have it bled and it would work for a while then malfunction again. Reason being that the air bubbles in the Dot 5 are very, very, very, very difficult to remove. And the rear brake hose having to go up and over the caliper would tend to trap air at its highest point and when at altitude air expands and voila, no rear brake. Of course I didn't know or understand all this until years after I'd traded that bike. So I absolutely deplore Dot 5 fluid.

There is a newer Dot 5.1 that is glycol based like the other fluids and it is said to be A-OK but I've not tried it.

As for flushing the fluid every two years I am now a believer. Few years ago riding two up pulling a trailer going up the Sandia Crest Byway I lost both my rear brake and my clutch due to the brake fluid getting too hot and boiling in the lines which run way too close to the hot exhaust. After cooling off for a half hour or so everything functioned normally but I got the lines flushed asap at the dealer in Santa Fe and the fluid was beyond nasty - it was hideous. So at least every two years flush the lines for sure for optimum functionality.

Jack Klarich · Nov 30, 2017

ultrafxr said:
Good info. A little background on what I learned over the years about brake fluid. Dot 5 is silicone based but the reason is that when the spec came out only the silicone fluid could meet it. Being silicone based was not a requirement but that is what transpired. Like Jack said H-D used silicone based Dot 5 for a few years and from my experience it was a failure. My '99 ultra would lose its rear brake any time I was riding in the mountains. I'd have it bled and it would work for a while then malfunction again. Reason being that the air bubbles in the Dot 5 are very, very, very, very difficult to remove. And the rear brake hose having to go up and over the caliper would tend to trap air at its highest point and when at altitude air expands and voila, no rear brake. Of course I didn't know or understand all this until years after I'd traded that bike. So I absolutely deplore Dot 5 fluid.

There is a newer Dot 5.1 that is glycol based like the other fluids and it is said to be A-OK but I've not tried it.

As for flushing the fluid every two years I am now a believer. Few years ago riding two up pulling a trailer going up the Sandia Crest Byway I lost both my rear brake and my clutch due to the brake fluid getting too hot and boiling in the lines which run way too close to the hot exhaust. After cooling off for a half hour or so everything functioned normally but I got the lines flushed asap at the dealer in Santa Fe and the fluid was beyond nasty - it was hideous. So at least every two years flush the lines for sure for optimum functionality.

Very good info

I am not convinced yet with the New and improved silicone based synthetic brake fluid

I can understand kind of how the airline industry bys into this kind of fluid, but IMO with out more improvements and testing I will not be using it

When I taught brake class I had lots of questions to answer about brake fluids

My short answer was keep it clean and flush it often

It does not matter how good your bike runs or how fast it is, when yu mash the brakes they best be working good OR BADJU JU will visit you quickly

HDB0B · Dec 1, 2017

Dealer said the headpipes have to come off to bleed the brakes ..... is this true?

Bob

orag:

Jack Klarich · Dec 1, 2017

HDB0B said:
Dealer said the headpipes have to come off to bleed the brakes ..... is this true?

Bob orag:

I dunno why

the front brake lines are attatched to a manifold on the back side of the lower tripple tree, the exhaust does not run any where near this nor any bleeders

DK Custom Products · Dec 5, 2017

Is this an option???

J/K

Kevin

MDO · Dec 5, 2017

Does anyone know how to check your brake fluid moisture content with a digital voltmeter?

I will answer this tomorrow, so stay tuned.

Jack Klarich · Dec 5, 2017

MDO said:
Does anyone know how to check your brake fluid moisture content with a digital voltmeter?

I will answer this tomorrow, so stay tuned.

The same way you can test anti freeze, or you can use a Brake Shark

Kind of spendy tool tho very acurate

You can also get test srips to measure the copper content of the inner lignings wear from the steel brake lines, yes they do wear with the fluid pulseing thru them Over time this will degrade the fluid also

MDO · Dec 6, 2017

I know you all can't wait so here it is.

Using the VDC (volts direct current) setting on a DMM, put the negative black lead on a good ground near the reservoir & place the positive red lead in the brake fluid & it should read 0.3 VDC or less. Any higher & the fluid has too much moisture & should be flushed. As Jack said, you can also buy test strips or a dedicated tester for the brake fluid.

You can also use the ohm setting, but you will have to research that.

Jack Klarich · Dec 6, 2017

Thanks Michael

Did you learn that in the military?

I learned the test at a brake class in Chicago in 1981

I got to teach the class for the first time that day, the instructor showed us the test, got called away and put me in charge

When I returned to my store in MN I guess the nes got back before I did

The manager put me in charge of ALL in house brake training

After that I had to attend many seminars to stay fresh, but that test was a real easy but an eye opener too

Thanks for bringing it back out, it will help others, I am having some fond reminders of my miss spent youth LOL:clapping: