Master Cylinder Failure

[Old N' Grumpy]

the # is just a rating for boil points and quality. any and all no silicone (dot 5) fluids will work. dot3 is not preferred due to its low boiling point.

Thank you again!

 

[atomsplitter]

Here's an exploded view of your brake line spaghetti:

To actuate the ABS valve you will need either a Dealer Tool or TuneECU. The brake lines can be flushed and bled without actuating the valve but if you want the ABS part to work properly, that needs some attention as well (i.e. flushed and bled).

 

[Old N' Grumpy]

Here's an exploded view of your brake line spaghetti:

To actuate the ABS valve you will need either a Dealer Tool or TuneECU. The brake lines can be flushed and bled without actuating the valve but if you want the ABS part to work properly, that needs some attention as well (i.e. flushed and bled).

****…now it’s gonna be a mission. I was hoping for a fast n ez fix so I could sell the bike. I will have to double check n be sure I have ABS first when I get back home.

 

[Mongler07]

****…now it’s gonna be a mission. I was hoping for a fast n ez fix so I could sell the bike. I will have to double check n be sure I have ABS first when I get back home.

Tune ECU is cheap and easy to do, especially if your close to someone who has one! unless the system was ran dry... does not sound like it, just bleed the brake fluid, its probably fine.
What shop did you take her to that said the master needed replacing or rebuilding? typically that is NOT a issue on a system that gets some sort of maintenance.
just flush/bleed it and see what happens. if that does not work then go to plan B.

 

[Old N' Grumpy]

Tune ECU is cheap and easy to do, especially if your close to someone who has one! unless the system was ran dry... does not sound like it, just bleed the brake fluid, its probably fine.
What shop did you take her to that said the master needed replacing or rebuilding? typically that is NOT a issue on a system that gets some sort of maintenance.
just flush/bleed it and see what happens. if that does not work then go to plan B.

Will do…leaving tomorrow. Been stuck up in N Florida due to the hurricane. Thanks man!

 

[R-III-R Turbo]

Before you spend money you can test the master cylinder by blanking off the cylinder with several crush washers under the banjo bolt.
When bled this will give a rock solid lever, if the MC is working OK.

This is a rear brake MC from a ZX14R but the principal is the same;

If that works OK, the problem is overwhelmingly likely just air in the system of brake lines.
You can flush and bleed the whole system with fresh DOT 4.
And confirm the brake is indeed good

.

 

[1olbull]

Before you spend money you can test the master cylinder by blanking off the cylinder with several crush washers under the banjo bolt.
When bled this will give a rock solid lever, if the MC is working OK.

This is a rear brake MC from a ZX14R but the principal is the same;

If that works OK, the problem is overwhelmingly likely just air in the system of brake lines.
You can flush and bleed the whole system with fresh DOT 4.
And confirm the brake is indeed good

.

I am very interested in learning your tip. However, I do not understand this, "test the master cylinder by blanking off the cylinder with several crush washers under the banjo bolt" what is "blanking" and I see no banjo bolt or washers in your pix?
Gratitude.

 

[TURBO200R4]

I am very interested in learning your tip. However, I do not understand this, "test the master cylinder by blanking off the cylinder with several crush washers under the banjo bolt" what is "blanking" and I see no banjo bolt or washers in your pix?
Gratitude.

If you remove the brake hose and banjo nut then use the spacers to take up the clearance then the fluid has nowhere to go therefore the pedal should be solid
Hth

 

[Mongler07]

I am very interested in learning your tip. However, I do not understand this, "test the master cylinder by blanking off the cylinder with several crush washers under the banjo bolt" what is "blanking" and I see no banjo bolt or washers in your pix?
Gratitude.

Banjo bolts are already there. Go buy a $2 steel spacer that fits the banjo bolt. Let it fill with fluid with a pump or 2 as you tighten it to be bled.
It's a clever way to test a system. I did it once to find a pinhole in a fitting once.
His picture is of the rear brake master btw. Thus why it looks a little confusing. Can be done at the end of a brake line with a regular bolt too.

 

[Gerald]

Banjo bolts are already there. Go buy a $2 steel spacer that fits the banjo bolt. Let it fill with fluid with a pump or 2 as you tighten it to be bled.
It's a clever way to test a system. I did it once to find a pinhole in a fitting once.
His picture is of the rear brake master btw. Thus why it looks a little confusing. Can be done at the end of a brake line with a regular bolt too.

You would still need a compression washer on each side of the spacer to not have a leak. Goodway to check for by-pass inside M.C.. Good tip R-III-R Turbo