Tips for bleeding TRP Hylex brakes

[A1CKot]

So I could use a little help with these brakes. I shortened the line on my rear brake today and I've tried to bleed it twice. Both times the lever pulls all the way to the bar with very little pad movement.

I have it set up per the instructions. Bleed screw at the lever removed and bleed fitting and exit hose running into a container. Bleed screw at the caliper removed and fitting installed with syringe full of fluid. Push the fluid from the caliper to the lever until there are no bubbles and close up the lever. Remove syringe and install bleed screw in the caliper and pump the brakes. Same result both times. Extremely spongy lever...

So does this sound right? Am I not putting enough fluid through the system? Do I need to orient the bike so the caliper is higher than the lever? Thanks for the help.

[oldpotatoe]

So I could use a little help with these brakes. I shortened the line on my rear brake today and I've tried to bleed it twice. Both times the lever pulls all the way to the bar with very little pad movement.

I have it set up per the instructions. Bleed screw at the lever removed and bleed fitting and exit hose running into a container. Bleed screw at the caliper removed and fitting installed with syringe full of fluid. Push the fluid from the caliper to the lever until there are no bubbles and close up the lever. Remove syringe and install bleed screw in the caliper and pump the brakes. Same result both times. Extremely spongy lever...

So does this sound right? Am I not putting enough fluid through the system? Do I need to orient the bike so the caliper is higher than the lever? Thanks for the help.

I think when you are removing the syringe at the caliper, that's when you are introducing air. I'd try to remove syringe at caliper, then tap, tap, tap line and lever with the lever opened, looking for bubbles. Lever higher than caliper, reservoir level.

[tigoat]

I have done several sets of Hylex brakes so far and I have not seen a problem with the levers coming close to the bars. TRP is actually very lousy with instructions so I had to do it my way. There are multiple ways to do this but the end result should be the same, which is with oil filled the whole hydraulic system free of bubbles.

Here are steps of what I did:

1. Assuming you installed the line correctly back to the caliper. Remove the bleed screw at the caliper and attach the syringe with full of mineral oil. Make sure you tape the syringe to remove all the air bubbles.

2. Remove the bleed at the lever and attach another syringe without oil and with the plunger removed. Ideally, the tube should be very short so the syringe is stand upright perpendicular to the ground.

3. Now push the oil slowly through the line from the caliper. Oil should come up into the syringe at the lever. After close to empting the oil from the syringe, tap the syringe a few times at the lever and then squeeze the lever a few times to free more bubbles from the line. Air bubbles are lighter than liquid so they should rise up with oil sinking down.

4. Plug the plunger into the syringe at the lever to "close the loop" at the top. Then remove the plunger from the syringe at the caliper. Now push the oil back down at the lever to get whatever bubbles left at the caliper. With a Shimano system, you would open and close the nipple rapidly at this stage. Unfortunately, there is no bleed nipple for the Hylex so this is how I would do it.

5. Now remove the syringe at the caliper and replace the bleed screw while the syringe is still closed at the lever. The idea is not to have both ends open, as fluid with drain if that is the case. That is why you always close the top at the lever before closing the bleed port at the caliper.

6. Now with the caliper closed and sealed, try to push the oil into the system at the lever while pumping the lever repeatedly. It should be very hard to push oil into the system at this point and the lever should be very firm at this point. Remove the syringe and replace the cover the screw to finish the job. Oil will be messy around the lever so make sure you wipe it down really good with alcohol.

That's about it.

[A1CKot]

Thanks for the help. I will give this a try when I get off work today.

[A1CKot]

Thanks again for the help. Two more failed attempts and I realized that I needed to place the caliper in an upright position with the hose perpendicular to the ground. Both brakes are now working great. This was definitely more difficulty than the Shimano and Hope systems I've used but now I know how to do it.

[NHAero]

This was a helpful thread, thanks. Sure would be nice if these things had a proper bleed screw...

[austex]

I have done several sets of Hylex brakes so far and I have not seen a problem with the levers coming close to the bars. TRP is actually very lousy with instructions so I had to do it my way. There are multiple ways to do this but the end result should be the same, which is with oil filled the whole hydraulic system free of bubbles.

Here are steps of what I did:

1. Assuming you installed the line correctly back to the caliper. Remove the bleed screw at the caliper and attach the syringe with full of mineral oil. Make sure you tape the syringe to remove all the air bubbles.

2. Remove the bleed at the lever and attach another syringe without oil and with the plunger removed. Ideally, the tube should be very short so the syringe is stand upright perpendicular to the ground.

3. Now push the oil slowly through the line from the caliper. Oil should come up into the syringe at the lever. After close to empting the oil from the syringe, tap the syringe a few times at the lever and then squeeze the lever a few times to free more bubbles from the line. Air bubbles are lighter than liquid so they should rise up with oil sinking down.

4. Plug the plunger into the syringe at the lever to "close the loop" at the top. Then remove the plunger from the syringe at the caliper. Now push the oil back down at the lever to get whatever bubbles left at the caliper. With a Shimano system, you would open and close the nipple rapidly at this stage. Unfortunately, there is no bleed nipple for the Hylex so this is how I would do it.

5. Now remove the syringe at the caliper and replace the bleed screw while the syringe is still closed at the lever. The idea is not to have both ends open, as fluid with drain if that is the case. That is why you always close the top at the lever before closing the bleed port at the caliper.

6. Now with the caliper closed and sealed, try to push the oil into the system at the lever while pumping the lever repeatedly. It should be very hard to push oil into the system at this point and the lever should be very firm at this point. Remove the syringe and replace the cover the screw to finish the job. Oil will be messy around the lever so make sure you wipe it down really good with alcohol.

That's about it.

Resurrecting 'cause I am having difficulty. Swapped banjo fittings at levers so I'd have my preferred right-front braking. Right-front system is firm and solid, left-rear is a little soft. With Tektro bleed kit hooked up as above, I can't seem to push any fluid from caliper. In fact, I pushed hard enough that the tube popped off the syringe:mad:. Seems like there is a blockage to "reverse" pressure, though brake does work, just softer than front. Any ideas? Thanks.

[tigoat]

Resurrecting 'cause I am having difficulty. Swapped banjo fittings at levers so I'd have my preferred right-front braking. Right-front system is firm and solid, left-rear is a little soft. With Tektro bleed kit hooked up as above, I can't seem to push any fluid from caliper. In fact, I pushed hard enough that the tube popped off the syringe:mad:. Seems like there is a blockage to "reverse" pressure, though brake does work, just softer than front. Any ideas? Thanks.

I think you have the system closed. There is a small hole in front of the each lever that allows you to adjust the travel, which I think it might have been adjusted too far out, closing the system.

[Gummee]

Resurrecting 'cause I am having difficulty. Swapped banjo fittings at levers so I'd have my preferred right-front braking. Right-front system is firm and solid, left-rear is a little soft. With Tektro bleed kit hooked up as above, I can't seem to push any fluid from caliper. In fact, I pushed hard enough that the tube popped off the syringe:mad:. Seems like there is a blockage to "reverse" pressure, though brake does work, just softer than front. Any ideas? Thanks.

On my 'now swapped back from right front' set of Hylex brakes, the rear is now less 'solid' feeling than the front. ...like the opposite previously.

Must be something about short vs long hoses

M

[austex]

tigoat:
thx, I'll give this a shot.

Gummee:
I'll report back if I have better success firming up the rear.

[Marburg]

I think you have the system closed. There is a small hole in front of the each lever that allows you to adjust the travel, which I think it might have been adjusted too far out, closing the system.

Tho ancient, bumping this thread because I had exactly this problem.

Bleeding a pair of older (non-RS) Hylex. I was using the Jagwire Pro system with the banjos from the HFA802 kit.

And darn it, I couldn't get fluid to push through from the calipers no matter what I tried. Thought the banjos were too small, thought I was going crazy.

Backing out the travel adjustment screw was the trick. Took a little fussing to find the right position where the system was truly open, but once done the bleeding was A-OK.