"Pushing" fluid into rear brakes

[Killer Whale KTM]

Guys,
Should I be able to push fluid from the nipple on the rear brake up into the reservoir ?? I was able to do on the front. I read that if you need to change your fluid that its better to push it in from the bottom with some sort of syringe so that you have no air bubbles and no need to bleed it for the next 20 minutes. What am I missing ?
I searched the how to with no luck.
Thanks,
Killer Whale KTM

[Peanuts]

Yes, it's the best way.

Although if the system alreadt has fluid in it there is no reason why you cannot simply pump the new fluid through with the master cylinder. Open nipple, press pedal, close nipple, release pedal etc. Dont let the reservoir run too low though!

[geometrician]

.KTM's factory tool pushes the fluid in from the master cylinder reservoir. The reservoir adaptors vary from model to model, the pressurized pump/supply itself is German and quite pricey. I think our dealership spent about $2000 on the entire setup FWIW you have to buy whatever tools KTM sends you

It doesn't matter which way you do it so long as you have the volume in your pump/syringe to completely fill the system w/o stopping.

I use a big syringe (100cc from a paramedic customer) to shove fluid through the bleeder bolt. I keep one marked "5.1" for brake fluid & another "oil" for the hydraulic clutch system where I use 5w fork oil/suspension fluid instead of the Magura or Motorex offerings.

I use a piece of safety wire looped around the plunger-end of the syringe body so I can keep it upright while fiddling with the process and not put any stress on the hoses- we've all had bleeder hoses pop-off in the middle of a job leading to air introduction nevermind the mess. Keep your syringe lines short so you don't waste or contaminate unused fluid. I take the plunger out and (with the lines connected & my bleeder wrench in place) fill the body with (whatever) fluid. Then I crack the bleeder bolt (not too far or you can suck air past the loose threads) to watch for the (usual) air bubble that comes out. Once the bubble has come to the top of the syringe, I place the plunger back in & begin to push down to push fluid into the system. Of course you'll want some dirty rags to catch the fluid that comes up out of the reservoir. Once it comes through clean close the bleeder bolt & you're done!

One advantage of the pressurized units forcing fluids through the system is air bubbles (which always stay in the highest loop of a line) can be pushed through- but this is dependant on the speed the fluid flows

[Killer Whale KTM]

Thanks for the replies.
I think I was doing it correctly but for some reason it would not go through. I also noticed, while bleeding conventionally that when I loosened the bleeder bolt that the fluid came out the threads around the bolt instead of the top. I suppose I should check to see if it is clogged up some how. When I couldn't push through the fluid ,I thought maybe it had something to do with the anti-lock brake system. As I recall it took me 2 tries with the front also. I'll try again this afternoon before I ride.
Thanks again,
Killer Whale KTM

[charlie264]

My preferred way is to use a big syringe and pipe to push fluid from nipple to reservoir... Always feels wooden when bled normally, as Peanuts described.

[Peanuts]

Originally Posted by Killer Whale KTM

Thanks for the replies.
I think I was doing it correctly but for some reason it would not go through. I also noticed, while bleeding conventionally that when I loosened the bleeder bolt that the fluid came out the threads around the bolt instead of the top. I suppose I should check to see if it is clogged up some how. When I couldn't push through the fluid ,I thought maybe it had something to do with the anti-lock brake system. As I recall it took me 2 tries with the front also. I'll try again this afternoon before I ride.
Thanks again,
Killer Whale KTM

Check that you have free play on the rod that goes into the master cylinder.

[ridewestKTM]

You are not the only one to find this to be the case. I figured there was a check valve in the nipple area or something and gave up and went the other way.

[rossguzzi]

Me too !

[Dustodust]

IF IT WONT BACKBLEED
you need to back off the adjuster nut on the lever or the hole in the reservior may be blocked by the piston
it can also sometimes be blocked if the seal in the piston is distorted and stretched out until it blocks the hole

you can get a backbleed syringe at any Farm and Feed supply store for about $ .69 cents , they usually have buckets of them that they use for animals
it helps to push the air out of the line before attaching the hose and then hold the syringe and hose up and pull back on the syringe to bring the bubble back up before pushing the fluid, tapping on it helps bring the bubble up. If the bleeder valve is massivly leaking it helps to clean it an carefull use some grease on the threads to get it to seal

I like to use a MitiVac vacuum tool and pull it thru instead of pushing so I dont need to be concerned about the bleeder valve leaking

[Killer Whale KTM]

Thanks, Dust,
All good ideas that make sense. I'll try again as soon as I can.Slick muddy roads are not fun with bad back brakes !!
thanks again,
Killer Whale KTM

[Katoom72]

I did the 'put in oil and bleed' way once. Then i did the syringe + tube on nipple and push oil trough thing. I never did the first method again. If u have a proper syringe and tube to push the fluid trough the job is done in merely a few minutes. As for the old method that can take up to 20 minutes....

Gonna do the brake and clutch fluid soon, the old brake fluid looks like applejuice now and my brakes feel like a sponge.

[DirtJack]

You can put grease around the threads of the bleeder to cut down on air entering or escaping when the bleeder is open. Wipe off the excess grease after closing the bleeder valve. I usually use a syringe to remove almost all of the fluid in the reservoir and replace it with new fluid before bleeding whether pushing or pulling the fluid through the system.

[Killer Whale KTM]

Thanks, guys,
I'll try again as soon as I can. I'll bet that I need to loosen or detach the linkage as suggested. Got my fingers crossed !
Killer Whale KTM