TRR3 Roadster - Spongy Front Brake

[Joa]

Hi together,
I own a Rocket 3 Roadster (2016, ABS).
My front brake is terribly spongy, huge lever travel. I exchanged already all tubes, caliper sealings and pistons as well as piston in the brake pump. The system was bleed professionally including the ABS routine. However, no improvement. When pulling the lever it goes straight trough to the handle bar. Front Brake works only when I pump.
Has eventually someone a remedy hint.Y our support would be highly appreciated.
Cheers
Joa

 

[Sioux Falls Rocket]

Hi together,
I own a Rocket 3 Roadster (2016, ABS).
My front brake is terribly spongy, huge lever travel. I exchanged already all tubes, caliper sealings and pistons as well as piston in the brake pump. The system was bleed professionally including the ABS routine. However, no improvement. When pulling the lever it goes straight trough to the handle bar. Front Brake works only when I pump.
Has eventually someone a remedy hint.Y our support would be highly appreciated.
Cheers
Joa

That sounds like air in the lines... i would try bleeding it again...check seals again too!

 

[John Miller]

Agree - has to be an air lock in the system somewhere.

You might need to buy yourself a unit that will suck the air through the bleeder - you can get them from most auto parts stores - keeping the resevior full will be the challenge.

Good luck - been there before - not on a R3 (had an air bubble shuttling back and forth in a brake line many years ago, finally found it by purging each line in the system first).

 

[Sioux Falls Rocket]

Agree - has to be an air lock in the system somewhere.

Good luck - been there before - not on a R3 (had an air bubble shuttling back and forth in a brake line many years ago, finally found it by purging each line in the system first).

I would try a speed bleeder which attches to the bleed valve qnd creates a vacuum to help speed the process

 

[Pedro]

Tie back the brake leaver to the hand grip and leave over night .It may surprise you.You can use a cable tie or anything else that is easy to remove .

 

[Joa]

I don't think think it is air in the system. First, I am very experienced and second, I have these vacuum tools you recommend. I flushed around 10l (!) brake fluid trough the system. I guess it is rather a design flaw in the brake pump. There is a second hole in it's tank. When I pull the lever fluid comes out of this hole. When I close it, it more or less builds up properly pressure. However, with this second hole closed the brake is not releasing.
Best Regards Joa

 

[kipper]

Do we not need software to properly bleed the R3R ABS system ? My rockets are pre ABS.

 

[TURBO200R4]

I don't think think it is air in the system. First, I am very experienced and second, I have these vacuum tools you recommend. I flushed around 10l (!) brake fluid trough the system. I guess it is rather a design flaw in the brake pump. There is a second hole in it's tank. When I pull the lever fluid comes out of this hole. When I close it, it more or less builds up properly pressure. However, with this second hole closed the brake is not releasing.
Best Regards Joa

may be failure to understand on my part but if the hole is blocked u cannot bleed proper.
if u pry the pistons back it tends to push the air the up into the reservoir. cover reservoir

 

[Ishrub]

What did you replace the stock brake lines (tubes) with and did you replace all six (6)?
Factory stock lines are actually stainless steel under the rubber covers. I am not a mechanic or plumber re hydraulic pressures but the HEL aftermarket stainless steel brake line kit I have for the ABS R3 has six (6) brake lines of various lengths with the short ones being ABS component related.
Did you change ALL of the stock brake lines?
Could mixed and possibly different inner line diameters between factory and aftermarket lines affect the ABS design volumes and pressure calibration?

• HEL BRAKE LINE KIT FOR TRIUMPH ROCKET III ROADSTER ABS (2011-2013) 6 HOSES

https://www.cj-motor.com/assets/full/HEL335-6-HOSES-HBF8014-.jpg?20200624033445

SKU: HEL335-6-HOSES-HBF8014-

HEL BRAKE LINE KIT FOR TRIUMPH ROCKET III ROADSTER ABS (2011-2013) 6 HOSES​

Part Number: 6 HOSES HBF8014​

 

[Joa]

I took all your advices serious and started over again. By chance I got on weekend from AliExpress a strong hand vacuum pump (Link). I closed with the hand the tank on the handlebar and created a strong (!) vacuum in the brake system. By that means the last, hidden and sticking small air bubbles became bigger and moved inside the system. When quickly released the hand from the tank I created a kind of hydraulic shockwave. It blew out the last air bubbles.
It works now like a beauty, better then ever.
Thanks to all
Cheers Joa