Changing brake lines.

Changing the brake lines is something most of us will either have to do or have to pay someone to do at some point. What follows is a quick glimpse into what is required to do the job without losing the paint off your bike.

Buying the Brake Lines.

The most popular choice is the stainless steal braided type hose. Popular makes are Goodridge and Earls. Both sorts consist of a PTFE inner core which carries the fluid, this on a Goodridge hose is rated to a burst pressure of 60,000psi which is far more than even a car uses. On the outside there is a stainless steal braid which protects the core. At each end of the pipe will be fittings made from either Chrome, Cadmium plated steal, Stainless steal or anodized Aluminium. All the fitting work in the same way but are different to look at. Cadmium and Chrome for example are prone to rust and Aluminium is multicoloured, the stainless looks like chrome but will look like new chrome even after a hard and salty winter.

The other type is the same as what you already have, black and rubbery.

When you buy braided lines you will be given a choice. Two lines or three. The reason being that the Fireblade, in common with the VFR and CBR, has as standard a three line brake setup consisting of a brake line from the master cylinder to a splitter and then one line to each brake caliper. The problem with this setup is that the splitter has to be replaced and a new stainless item costs a fortune and increases the cost of the set by the cost of an extra line and fittings as well. To get around this cost there is the option for a two line setup. This is basically two lines (duh) that go from the master cylinder straight to the calipers. The bonus is that you only need four fittings rather than six plus the splitter. Another bonus is a little extra feel at the lever due to extra fluid volume (email me if you want to know why).

 I have only dealt with Goodridge myself but believe the installation should be the same for all types.

Installation

First off you are going to have to remove the old brake lines. This should be done with great care as the fluid loves to eat paint. Whenever I have done this I have had loads of rags and a bucket of clean water handy just in case. The safest bet would be to remove the fairing completely. Cover the bike around the Brake master cylinder and the front mudguard with rags so that any spilt fluid will caught rather than ruin the paint. Undo one of the Bolts that secure the hoses to the calipers, if you are using a side stand rather than a paddock stand then undue the left hand side first. Fluid will start to drip from the hole in the fitting, find a way to catch the drips (a plastic bag taped to the hose is a good bet). Then with a rag in your other hand undo the top hose from the master cylinder. The fluid will then rush out into the bag at the bottom. Do the same with the other caliper bolt. You are now free to remove the entire hose system from the bike. Plug the hole in the master cylinder then rinse down the bike just in case. 

Now its time to fit the new hoses!!!

2 line kits.

With a 2 line kit the very minimum of parts you get will be 2 hoses complete with fittings, a double banjo bolt and seven copper washers. You can reuse your old caliper bolts but never the washers. New bolts would look nice though eh? You will need some brake fluid too, DOT 5 is the highest available but DOT 4 is more than enough.

On the hoses will be Banjo fittings, they are called Banjo because of their shape, they look like small banjos. One of the hoses will have a straight banjo at one end, this is the top. The longer hose will be for the left hand caliper. The Banjos will be oriented on the hose such that they line up with the caliper bolts when the other end is attached to the master cylinder. So the first thing to do is to put the large banjo bolt through the top two banjos with the straight banjo closest to the master cylinder with the curved one curving away. Screw the bolt in part of the way just to position the hoses, you can fit the washers later when you know the hoses are the right way up. Now route the lines down to the calipers so they don't fowl any of the bikes bits and then position them with the bolts in the calipers. If the fittings don't line up properly with the calipers try the hose the other way up. Check the steering and suspension travel of the bike doesn't cause the hoses to stretch or fowl anything by steering lock to lock and lifting the front wheel off the ground (I once heard of a guy who made his own brake lines up, they didn't have enough slack, he pulled a wheelie and the forks extended pulling the hoses from the fittings leaving him with no brakes!!). Now you can secure the hoses to the calipers and master cylinder not forgetting to put a washer each side of every banjo, three at the top, washer/banjo/washer/banjo/washer, two at the bottom, washer/banjo/washer. Make sure the hoses don't flap around in the breeze and the hard bit is done. All you have to do is bleed the buggers and you're away!!

3 line kits

The basic fitting is the same although the positioning is a little easier to see.

Bleeding (hell)

This is by far the most boring part of the entire process. What you need to do is remove the top from the master cylinder so that you can pour fluid in. You may find that the reservoir is completely empty so put some in and fill it to the top. Now using a piece of washer tube as a runoff pipe connect the caliper bleed nipples to a nearby empty container (a milk bottle is great but don't give it back to the milkie). Open the nipples and then pump the brake lever, you should see little bubbles coming up through the fluid in the reservoir, pump until fluid starts to dribble out the runoff tubes then close off the nipples. From now on you will either need an assistant or a lot of patience. Pull the lever backwards and at the same time open a nipple. Once the lever is all the way back to the bar, close the nipple and repeat. Do this on both sides until the fluid is coming out completely free from air bubbles and there is firm resistance from the lever when the nipples are closed. Pull the bar back with the nipples closed and check the system for leeks and recheck for chaffing and stretching. Put your tools away, hoses the front wheel down and go for a gentle (at first) test ride.

Cheating.

I used to fit Goodridge hoses as part of my job (If you have ever bought hoses from Skidmarx between 07/93 and 12/94 then I made them!) and I once spent almost an entire day trying to bleed the new hoses on my trusty XJ650. I was getting nowhere. We had purchased one of those easy bleed things that you get for cars which has a cap that you screw over the top of the master cylinder. Then using a spare tyre as a pressure source you push fluid through the system so that all you have to do is open the bleed nipples and you're away!. This was a great idea, shame that bikes very mostly have square master cylinders with 2 securing screws.  We had given up on this and thrown it into a corner in disgust. In desperation I retrieved the item from the corner (I didn't want to take the van home for a third night running!). Instead of trying to push fluid down the system, why not push it up and around the system? So I took the plastic adapter from the end of the easybleed and pushed the tube onto the bleed nipple on one of the calipers. On the other caliper I still had that runoff tube into a milk bottle. I opened both calipers and ensured that the top was on the master cylinder in case of blowback and then attached the easybleed to the front tyre. Whoosh!! fluid started spurting from the other caliper so I took the easybleed off the tyre and did up both nipples. Now with the system full of fluid with a little air rather than a system full of air with a little fluid I was able to give it a quick final bleed and voila! Bob's your auntie's new lodger. Quick test ride to the nearest garage for some air in the front tyre. Job Done.

Another  easy cheat

 This one requires no special tools, just a bit of forethought. Before you start the job, take out the pads from both calipers. Pump the lever a lcouple of times so that the pistons move out a bit, if your pads are/were past their best then you have enough piston showing anyway. Fit the hoses as described above. Now it's time for bleeding the lines you have a ready source of fluid that can be easily pumped around the system. In a 2 line kit all you need to do is open one bleed nipple and then gently push the pistons back in on the opposite caliper. Then close the nipple and swap sides. This should fill the lines with fluid making bleeding a breeze.

On a 3 line kit the above will only fill the bottom section of pipes with fluid. After you have pushed one set of pistons back in then tighten both caliper nipples and loosen the top banjo bolt slightly. Wrap a rag around the top bolt and then push the other set of pistons back into the caliper. This should force fluid upto the top of the system and the air out.  Retighten the top bolt.

Now all you have to do is fill the resevoir with fresh fluid and pump it through the system using the method in the Bleeding  section.

The Back Brake.

Doing the back line on a blade is similar in to the front but the benefits are completely lost on me. All my rear brake is good for is turning the brake light on or stopping the bike rolling backwards at junctions. Trying to stop using just the back brake is as effective as using the Fred Flintstone method and putting your feet down. You may say what about in the wet? But honestly can you say there is going to be enough difference to notice?

Having said all that i did change the line on the back. It did make bugger all difference but it did look better :-)