Jump to content

Need help with Brembo front brake bleed - KTM500

By NW_E-rider,
in 250-530 4 Stroke Enduro

 Share

Recommended Posts

Community Regular

NW_E-rider

Posted
Posted

2013 KTM 500EXC however front master cylinders (Brembo) were similar on all modern KTM/Husky so just about anyone can help me out here...at my wits end with my front brakes!

- Front brakes worked fine in September; parked bike for awhile (life got in the way of riding)

- Early Nov found I had about 1% front brakes as in couldn't stop bike pushing in garage, lever barely moved caliper cylinders; tied bleeding and no improvement.  Took off master cylinder, no pressure at outlet when cycling lever so figured had to be seals

- Dealt with Slavens Racing sending me the wrong rebuild kit...then not overnighting new kit as agreed upon; borrowed buddy's bike to ride last weekend.

- Installed new kit tonight, connected line, filled MC with brake fluid.  First 10 pumps or so I saw single bubbles come out of MC.  No significant pressure building.

- Tried to bleed again.  Nothing.  Bought a mitivac vacuum bleeder.  Hardly any fluid came out.  Likely about the amount left in the caliper and line to MC.

- Cycled lever a hundred times.  Saw a few more bubbles rise yet no pressure build.  

- Can't get any more fluid out of bleed port on caliper despite MC full of fluid.

 

What should I try next???  Running out of patience...and Saturday is the next ride.  

 

Link to comment
Share on other sites
Enthusiast

Earthmover

Posted
Posted


Pull the brake lever 3 4 times, hold it pulled in and open the banjo bolt that connects the hose to the brake cylinder, close it back, then relese the lever. Repeat this for 5 - 10 times or more until you see no air coming out between the copper washers of the banjo bolt.
Ater that do the same procedure to the banjo that connects the line to the caliper, until you see clear oil coming out without any air sings.
Only after you did that - proceed to the bleeding nipple sitting on the caliper and repeat - pull the brake lever 3 4 times, hold it and open the bleeding nipple, close it back and relese the lever. Do that for 5-10 times or as much needed for you to see clear oil coming out and your done.
KEEP THE OIL BOWL AT THE CYLINDER RESERVOIR ALWAYS FILLED UP TO 1/2 - 3/4 OIL HEIGHT.

  • Like 1
Link to comment
Share on other sites
Grand Master

orangyktmthing

Posted
Posted

Pull the brake lever 3 4 times, hold it pulled in and open the banjo bolt that connects the hose to the brake cylinder, close it back, then relese the lever. Repeat this for 5 - 10 times or more until you see no air coming out between the copper washers of the banjo bolt.
Ater that do the same procedure to the banjo that connects the line to the caliper, until you see clear oil coming out without any air sings.
Only after you did that - proceed to the bleeding nipple sitting on the caliper and repeat - pull the brake lever 3 4 times, hold it and open the bleeding nipple, close it back and relese the lever. Do that for 5-10 times or as much needed for you to see clear oil coming out and your done.
KEEP THE OIL BOWL AT THE CYLINDER RESERVOIR ALWAYS FILLED UP TO 1/2 - 3/4 OIL HEIGHT.

Nope. Not on a ktm. The correct procedure would be to reverse bleed through the caliper with a syringe full of brake fluid connected via a tube to the banjo bolt. Also, keep another syringe handy to pull the excess oil out of the master cylinder. A farm & garden store (like tractor supply) should have a good selection of non luer lock syringes that work just as well as the brembo or magura bleed kits.
  • Like 3
Link to comment
Share on other sites
Grand Master

Burnrider

Posted
Posted

I do the orange thingy method.

The 2013 and my '17 both have the same OEM banjo bolt. It's a steel bolt with a slot on one side for oil flow. Works great when there's no air in the system, but miserable to bleed for tight brakes.

I had to go with a galfer longer cable for the HDB setup and couldn't bleed the brakes using that slug. Galfer included real banjo bolts to move oil and air. I double drilled it same as the 450 and it bleeds / fluid air from the bottom up with a syringe.

Check it out - If this is what you have in the bike, ditch it. 

54813020100HOLLOW SCREW BLACK M10X1X19

  • Like 1
Link to comment
Share on other sites
Community Regular

NW_E-rider

Posted
  • Author
Posted

orangyktmthing- To clarify you state to attach syringe and tube to the banjo bolt on caliper...did you mean attach to bleed nipple on caliper?  If attached to banjo wouldn't fluid leak out when you remove syringe and attach to caliper?  

Burnrider- Indeed I have factory banjo bolt with single slot on one side.  Are you saying you used a different banjo bolt from Galfer and double drilled the new banjo bolt?  Or does drilling factory banjo bolt work?  Will go search archives for 'drilling banjo bolt'.

p.s. After reading TT and KTMtalk threads last night, I am a bit pissed at my brand.  Seems like enough people have had enough problems that KTM should have done something to fix this already...I see Husky (white KTM) went to a Magura MC on the 2018 models...wonder if that is in (slow) response to these field issues.  

Link to comment
Share on other sites
Grand Master

Burnrider

Posted
Posted (edited)
Quote

Burnrider- Indeed I have factory banjo bolt with single slot on one side.  Are you saying you used a different banjo bolt from Galfer and double drilled the new banjo bolt?  Or does drilling factory banjo bolt work?  Will go search archives for 'drilling banjo bolt'.

You need the standard banjo bolt installed at the M/C on the bars. It has a blind hole thru the center and one side hole. (10mm X 1.0 X 19mm). Tension the bolt down and mark the 12 0' clock position. Remove it for 2nd hole location. If it's at the bottom 1/2 of the clock (3:00 to 9:00) drill a 2nd hole at the 12 o' clock position to help bleed air. Above the clock circle and it should be fine with the single hole. Some riders just run a smaller drill through the other side of the bolt and call it good no matter where holes line up. The banjo bolts should be an accessory item sold in shops for Euro threaded bikes. Not sure if KTM subs the side slot model for all the KTMs.

DSCN1416.JPG

This is the choke point when we try to filter the reservoir from the slave cylinder bleeder bolt. It can trap air at the bottom hole location or resist syringe pressure altogether.

 

 

Edited by Burnrider
  • Like 2
Link to comment
Share on other sites
Mentor

travertt

Posted
Posted

Very interesting....I have had a somewhat similar problem with my front brake for almost 2 years.  I rebuilt the MC...problem never went away.

In my case the issue is more of an annoyance that a ride-breaker. If the bike sits for more than a week or so, the front brake system has low or zero pressure in it....the lever can pull back all the way to the bar with no resistance.  BUT....if I tape the lever to the bar and wait for a while, or if I vigorously work the brake lever....full pressure comes back and will be fine for a week of so.

I cannot figure our what the problem is..I have bled the brake numerous times since the MC re-build.

I just may try drilling that bolt...I'm not quite sure why that would help based on my actual symptoms....but I can't figure out what the actual problem is either...so what have I got to lose!

Thanks for the info!

Link to comment
Share on other sites
Grand Master

Burnrider

Posted
Posted
Quote

In my case the issue is more of an annoyance that a ride-breaker. If the bike sits for more than a week or so, the front brake system has low or zero pressure in it....the lever can pull back all the way to the bar with no resistance.  BUT....if I tape the lever to the bar and wait for a while, or if I vigorously work the brake lever....full pressure comes back and will be fine for a week of so.

Lots of Nissan m/c's on KTMs because of this problem. On the clutch M/C bleeding is improved by backing out the lever screw all the way. It's supposed to prevent the piston from partially blocking the fluid port making it easy to bleed. Anything making it easy to force fluid into the system should help displace air.

Link to comment
Share on other sites
Grand Master

Mike in Fresno

Posted
Posted

it is true that the Nissin MC does the trick. I used it on one of my bikes to see if the hype was true. Used the stock line on the KTM and the Nissin bolt.

But, I have made all mine work when I do have the occasional problem. I first tie the lever back all the way to the grip with a zip tie over night. Turn the bars so the MC is the highest point of the brake line system. Make sure the loop in the line is pulled down a little to keep it lower than the MC. At first and occasionally tap the brake line to keep the bubbles rising. The next day take off the zip tie and 9 out of ten of the soft brake issue will be gone.

If that doesn't work then I use the bottom up bleed method. Cracking the banjos speeds up the process. I hang a 5 gal bucket over the bar end and let the fluid overflow into it. I then clean the bars up with spray brake cleaner.

On the trail when you crash or bike ends upside down you will sometimes have a soft brake. Use a tool, a stick, your foot to spread the caliper apart pushing the brake pads back so the caliper piston retracts as far as you can get it to go. This will do an internal bleed and push the fluid and air bubbles back up to the MC. You can also do this in the garage to sometimes fix the issue before trying a regular bleed.

  • Like 2
Link to comment
Share on other sites
  • 3 years later...
Grand Master

Burnrider

Posted
Posted
On 7/15/2021 at 6:42 PM, Ho3Assassain said:

So if anyone still reads this thread....brake caliper banjo bolts with out any holes, just 2 grooves going the length of the bolt are the style that cause problems? 

The 2 groove bolt has been in use for awhile. Just back your lever adjusters all the way for the piston to clear the port and bleed the system. That should do it.

  • Like 1
  • Helpful 1
Link to comment
Share on other sites
Grand Master

Burnrider

Posted
Posted

If you can push fluid up with a syringe freely or open the bottom caliper bleeder and have it run out under gravity, the system will bleed air for a solid brake. More points for lubing the caliper pins with a synthetic grease- but first air needs to be removed from the system.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...
Terms of Use
Copyright
Privacy Policy