Install aviation hoses on your motorcycle
Aircraft hoses have an advantage over conventional hoses: they do not deform under hydraulic pressure. This improves braking. The feel of the lever is better, the bite is larger. The installation of the hoses must be careful.
Difficulty level: not easy
– Aviation hose kit for your motorcycle, e.g. 99 euros at Goodridge distributed by Moto Axxe (thanks to Moto Axxe store for their kindness and technical competence: ZI St-Claude, 77 Pontault-Combault – open houses from 340 March to 23 April 1 .).
– Brake fluid SAE J1703, DOT 3, 4 or 5 as recommended by the manufacturer.
- Rags.
– Torque wrench for those with no experience in clamping force.
– Transparent tube connecting the brake caliper bleeder and a small container.
– When bleeding air in the circuit, pump like a patient with the brake lever, thinking that the bleeding will be faster. The air is crushed under pressure and turns into many tiny bubbles. An emulsion forms in the liquid. Blowing becomes impractical because the air rises with great difficulty. You just need to wait one hour for the emulsion to dissociate on its own to resume cleaning.
1- Why "aviation" hoses?
There are many hydraulic controls in planes. There are both small planes and very large ones. There is no doubt that the long hoses used cause pressure loss; In other words, they should not deform under pressure. When we fit these hoses to our bikes, they do not deform due to hydraulic pressure when braking, unlike conventional hoses. They expand, especially when they soften as a result of aging. Thus, part of the braking force is lost due to this deformation instead of being fully applied to the brake pads. Thus, the installation of aircraft hoses does not reduce the braking power of the brake calipers, but avoids its loss. From the pilot's point of view, the gain in feelings is obvious.
2- Choose your kit
There are two options in the aviation hose kit if there are two front calipers: either 3 original hoses with a distributor are replaced by three aviation hoses in the same way, or two long aviation hoses start from the master cylinder on the steering wheel. reach out to each caliper. Opinions were divided, each his own choice. We chose the Goodrige kit (photo 2a, opposite), distributed by Moto Axxe, which includes three hoses, a distributor (photo 2b, below), new screws and gaskets. Please note that this distributor offers, for a single price of 99 Euros, the kit you need for any motorcycle. You have a choice: two or three hoses, the color of the hoses, the color of the banjo fittings.
3- Protect then dismantle
Above all, you must protect your motorcycle from inevitable brake fluid spills when removing old hoses. Brake fluid is very corrosive to paintwork materials. It leaves nasty marks, or worse, can cause a polymerization reaction with some plastics, making them as brittle as glass in a day or two. Install as many protective wipes as possible. Before the assembly of aviation hoses is completed, and especially during air purging, instantly wipe off any splashes that accidentally fall on unprotected parts. When removing old hoses, pay attention to how they run from the steering wheel to the distributor, if equipped, and then from there to the brake calipers.
4- Tighten while orienting
The hydraulic connection screws with new seals must be tightly tightened on the master cylinder on the handlebars, distributor and calipers (photo 4a, opposite). Pay attention to the correct angular position of each hose in question. Remember, perfect hydraulic circuit sealing is vital to safety. If pressure leaks, the brakes are completely damaged. This is not about tightening the screws with all your might, but rather tight, around 2,5 to 3 micrograms. If you are unsure of the clamping force, use a torque wrench. When installing aircraft hoses, especially if they have a braided metal shield, beware of possible rubbing against the plastic of the fairing and fenders, as well as all aluminum parts, as they will eat up the material a lot when the front fork is operating. (photo 4b below).
5- Silent cleaning
At the moment, there is only air in the new hoses. Brake fluid supplied from the master cylinder replaces air. Fluid is still present in the calipers. Be sure to add fluid as it goes down into the hoses (photo 5a, opposite). It is recommended to orient the handlebars so that the master cylinder bank is at a height higher than the rest of the hydraulic circuit. Pull the brake lever carefully (photo 5b, below). Air bubbles by themselves rise to the master cylinder and are sprayed into the vessel. It may happen that they remain in the bend of the hydraulic circuit. When turning the steering wheel, orient the hoses and therefore the distributor to benefit from this self-reliance phenomenon. As a result of the rocking, the lever hardens over time. To complete bleeding, place the clear tube at the outlet of the bleed screw on the caliper, the other end of the tube in the container. Open the bleed screw while applying the brake. Close it at the end of the lever stroke, release and restart the brake by opening the bleed tube until the bubble outlet has completely disappeared into the clear tube (photo 5c, below). Finish bleeding by opening and closing the screw BEFORE the end of the braking stroke.
