If you are looking to improve your bike’s braking ability, then upgrading the brake lines should be one of your first ports of call. Your motorcycle’s brake lines are very important as they deliver brake fluid under pressure from the master cylinder to the brakes allowing you to slow down and stop. Depending on how efficiently the brake lines deliver the fluid to the brakes has an impact on how well you can stop. As motorcycle modifications go, swapping your brake lines (or hoses, as they are often called) is one of the easiest and cost effective jobs you can do.
Some more expensive modern motorcycles are already equipped with braided brake lines as standard, but most still come equipped with cheaper rubber hoses as standard. These generally work fine but, over time and with extensive use, rubber hoses can become worn and will bulge under the pressure of applying the brakes. The continuous bulging effect of rubber hoses gradually but significantly reduces stopping power.
Aftermarket lines from the likes of Hel Performance, Goodridge and Venhill, are manufactured from the high quality materials including stainless steel, which is more durable and eliminates that ‘spongy’ feeling often found with rubber hoses under braking. The stainless steel exterior provides better resistance to any corrosion and abrasion, too.
So, upgrading standard rubber hoses to after-market braided brake lines will improve braking performance and inspire confidence both on road and on track. They also look trick too, and can often be specified in non-standard colours for further customisation. The good news is that to upgrade your bike’s brake lines won’t break the bank, and you can fit them yourself. Here’s how:
Offer up the new lines
Before picking up your tools, get your new braided brake lines and offer them up to ensure they’re long enough. All the aforementioned companies make their products in sizes especially for your bike, so do make sure you order the right lines for your particular make and model of motorcycle. There should be a bit of slack, especially if your forks compress when on the stand, and make sure the banjo end type matches those from the original brake lines.
Draining fluid and line removal
Once you’re happy that the new brake lines will fit, connect a tube to the bleed nipple and pump out as much brake fluid as you can. Make sure you have rag at the ready and remove the lower end of the brake lines and let the remaining fluid drain into a waste container. A good tip is to cut the fingers off a rubber glove and cable-tie them to the banjo fittings to catch any last drips. Finally, remove the top fitting and carefully remove the brake lines. Do take extra care, as brake fluid is corrosive and can cause costly (and unnecessary) damage if it gets on paintwork.
Check banjo bolts and washers
Compare the thread and length of the new brake line banjo bolts against the old ones and wipe both the caliper and master cylinder banjo fittings clean of any fluid, dirt and corrosion.
On twin-disc systems, loosely fit the right line to the caliper end (it’ll be shorter), then fit the left line to the left-hand caliper. Now bolt the hoses on at the top. If they have been installed correctly, there should be a copper washer between the bolt head and one line, both banjo ends, and the other banjo and the master cylinder.
Before going any further, make sure the routing of the new brake lines is ok. They should not be squashed against anything, kinked or stretched. Raise the front wheel off the ground with a paddock stand or main stand and ensure the lines don’t stretch when the forks are fully extended. Re-fit the cable clamps and guides to stop the lines getting close to anything where they could get pinched or rub.
Tighten and double check
It’s time to break out the torque wrench. Tighten each fitting to the specification outlined in your bike’s manual. Make sure any clips you’ve removed and re-fitted are tight too, then check the routing one last time.
Now you’re ready to refill the brake fluid. Clean the bleed nipples, remove and clean the master cylinder lid and get your new bottle of brake fluid ready.
Easy does it…
Hold the brake lever in and top up the reservoir, then release the lever. Attach your chosen bleeding device to the left-side banjo and loosen the bleed nipple. It may take a while for the system to start taking on fluid, if this is the case, try squeezing the lever slowly then releasing it as fast as possible.
Get rid of those bubbles
Once fluid is flowing on the left side, close the bleed nipple and switch to the right side. Get fluid to the caliper, then switch back to the left again. Push the fluid through until it’s coming out free of bubbles and lock the bleed nipple, wipe away any drips and fit a cover on the bleed nipple. Repeat this on the other side, fill the reservoir to the correct level and re-fit the lid.
Pump the lever
Finally, pump the brake lever to ensure the brake pads are in proper contact with the disc. Upgrading the pads can also be a relatively inexpensive modification for your bike, so if these need replaced it could be worth looking for higher performance alternatives and changing these at the same time.
Hold the brake lever in for a few seconds to make sure there isn’t a loss of pressure or any leaks. Now is a good time to give your bike a good clean!
And for bikes with ABS…
If your bike is ABS equipped, it’s a little more technical to replace the brake lines and you may want to ask a professional to do the upgrade. Pre-ABS bikes typically have one line on the back brake, and one of three layouts on the front if there are two calipers:
- Tee or Standard: One line from the master cylinder to a splitter that has a line going to each caliper
- Cross-over: One line to one caliper, with another line going over the mudguard to the other caliper
- Race: Two lines going straight from the master cylinder to each caliper
There isn’t a superior layout, the race layout is simply to meet ACU racing regulations.
As with all safety critical jobs, work is best carried out by professionals if you are uncertain of your own ability to carry out this modification.