I can't get my front brake to bleed properly...any trick?

doolin64 · Apr 2, 2014

So I replaced the front banjo bolt on the master cylinder with a Sicass Racing front brake switch. It came with a new copper washer. I purchased a second new from my dealer. This way both sides of the brake line have new washers.

I then tried conventional bleeding with a motion pro brake bleeder tool and I got nothing. Way too much air in the system.

I can't get it to bleed and now I'm front brakeless.

bushmechanic · Apr 2, 2014

sometimes the only way to get a front brake bled is with a syringe or bottle and a tube over the bleed nipple, empty the reservoir then force the fluid in at the caliper

air likes to go uphill

can instead take the master cyl off and put it lower down than the caliper if trying conventionally.

doolin64 · Apr 2, 2014

I'll have to see if I can grab a syringe locally. I've never tried that

fe390vt · Apr 2, 2014

you'll find an oversized syringe at the grocery store, where turkey pans and cooking utensils reside... rubber tubing, clamps at the auto parts store... prepare to get messy...

I've also tried depressing the front brake lever overnight with a strong rubber band to hold it in place, while the caliper dangles vertically below. Helped a bit but the air really likes to hide in the system.....

Idle · Apr 2, 2014

Sure the adjuster is not too tight?

I take the MC off the bar, and use the clamp to attach it to a piece of pipe.

Then set it up so there's no bend in the line, I'm hanging it from above..

Push the caliper pistons all the way in, then with MC level, I pump it up tight, then secure the lever with some tape. At this point the line is straight, and the MC is hanging sideways..

Leave for at least 4 hours or so and voillá! Solid brakes

*untie brake MC and position it in a level fashion before releasing lever slowly.

Kadowampus · Apr 2, 2014

Ya bleeding the front brakes can be a headache. I had the same problem on my 390 when I was servicing the fluid. There was a huge air bubble that was stuck at then banjo bolt at the lever. I ended up getting really lucky by turning the bars (while the bike was on a stand) so the lever was high and flicking the lever repeatedly. I was doing that because I was pissed I couldn't bleed it right then one of the flicks made a huge air bubble burp out in the master cylinder. After that I hade brakes! Pretty stupid how it happened but somehow my stupidity worked out.

BlueAndYellow · Apr 3, 2014

Howdy doolin64
I had the same problem on my FE450-12, in spite of bleeding the front break several times both the classic way and with a syringe from the bottom. No matter how I bleed them the break leaver would not get firm.

My issue was that a small air pocket was trapped at the very top by the pump / piston. I resolved it by removing the plastic dish in the bottom of the reservoir and then “tapping” / “drumming on” the break leaver. By depressing the break leaver a few millimeters in rapid succession and turning the bars I managed to remove the trapped air pocket. I had the lid removed from the reservoir so I could see the bubbles escaping. After a few minuscule bubbles surfaced the break lever was rock solid and I was happy.

N.b.
I installed the plastic dish again after the bleeding was done.
I have bleed breaks many times before and never have I had such difficulties as I had with the Husaberg front break. I was only moments way from ordering a break renovation kit when the issue resolved it self.

doolin64 · Apr 3, 2014

Thank you guys for all the tips. I'll be trying them out tomorrow night. Friday night wrenching sounds good to me!

steve · Apr 3, 2014

From one I prepared earlier:
DSMRA

doolin64 · Apr 3, 2014

BlueAndYellow said:
I resolved it by removing the plastic dish in the bottom of the reservoir and then “tapping” / “drumming on” the break leaver.

This worked for me along with reverse bleeding from the caliper up in a syringe. I had a heck of time snapping that little plastic piece back in to place. Got it done though and my breaks are back.

husawanabe · Apr 3, 2014

this method works good for me. get a new small oil pump can,fill it with brake fluid, attach a clear hose to the end,attach hose to caliper bleeder valve,crack bleeder valve and force the fluid up towards the master cylinder,you can usually see the air come thru the m/c.

Bigninjazx12r · Oct 8, 2014

I always do a gravity bleed then go for the conventional way. If I run into the issue of not getting all of the air out, I make sure to move the brake lever all the way forward until it hits the stop then squeeze. Some brake and clutch masters need this to get all of the air out. P.s. I've had to do this to a lot of different brand masters to get them air free.

thunderberger · Oct 12, 2014

i found an easy way, after failing many times i just drove the bike. the vibrations etc knocks the air free and brakes start working, so just drive it around , worked twice for me and nothing else has

Hoosaberg · Nov 3, 2014

There was a problem with spongy front brakes on another brand of bike that wasn't fixable. Some one concluded that most modern brake calipers no longer had O rings and that dirt gets between the piston and jams them up. I had that brand of bike and could not for the life of me get the brakes to stop being spongy. So popped all the pistons out, cleaned them re bled them and 'Hey presto'.

My Husaberg came with spongy brakes. I used to have to zip tie the brake lever to the bars the days leading up to a ride so I would have a firm lever. The brakes worked fine, the lever was just spongy. Bleeding didn't help. So I popped the pistons out, cleaned them, re bled and all good.

Same again with the wife's Cagiva rear brakes. Lost all pedal, couldn't buy an o ring kit for the master cylinder. So gave the piston cleaning trick a go and voila.

You'll find with the pistons cleaned, the brakes usually bleed much easier. If you take the caliper off and pull the brake lever, watch what the pistons do, often you'll see one move more than another.

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I can't get my front brake to bleed properly...any trick?

doolin64

bushmechanic

doolin64

fe390vt

Idle

Kadowampus

BlueAndYellow

doolin64

steve

doolin64

husawanabe

Bigninjazx12r

thunderberger

Hoosaberg

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