Thursday, June 4, 2009

Ford Focus Brake Pipe Replacement

Part 1

Following an advisory about corroded brake pipes at a recent MOT, I have ordered nearly all the parts I think I'll need to change them. This is going to be a challenging job for many reasons, and a job I really need to make sure I do properly, but I have booked a week for it, so I can take my time with it.

Here's a picture of all the parts I have ordered, although there's a few other bits and pieces coming in the post.


What you do it straighten out a length of copper pipe, then bend it into the shape you require, then use a special tool to flare the ends. There's two different types of flares, one of which fits into the other. The fittings simply tighten the two together creating a single seal which means you don't have to bother with tedious PTFE thread tape. Here's a male and female plug I made to stop leaks when I disconnect sections.


Jacked the car up today to take a look at how the existing pipe runs. The nearside rear runs from the brake, under the heat shield around the exhaust like this:



The offside rear runs from the brake, behind the fuel tank. Nightmare! I seriously don't want to remove the fuel tank. I have decided I shall re-route the new pipe work around the fuel tank. I have some brake pipe clips which can secure onto pre-existing areas on the car as depicted here.


So, both rear pipes meet forward of the fuel tank, and then run the length of the car along with the fuel lines, as shown here.



Once at the front of the car, they head up the bulkhead between engine and interior, and eventually connect onto the master cylinder.


Now the master cylinder is SERIOUSLY hard to get in at! But, I don't think I have to get in at it. There is a break in the pipe work at the bottom of the engine bulkhead and assuming the existing nut is in okay condition, I will simply replace from this point back to the brake, as this is the area affected worst by corrosion. Still gonna be MIGHTY fiddly, but doable.

The fronts are much easier, so perhaps I'll start with these and see how I go.

Anyone with experience see anything untoward with re-directing the pipe work around the fuel tank? Any other words of wisdom before I take the plunge?


Part 2

I undertook the challenge of replacing the brake pipes last week......it's a complete PITA, but not terribly difficult. I'll try to talk through the process, how I did it and any advice I could offer anyone undertaking a similar task. There is a lot of pictures, and I apologise for that, but at least it's all contained within the one thread and out of harm's way.....

So, to begin with, here's a snap shot of some of the tools used. Pressurised brake bleeder (thanks boogieman!), copper pipe, pipe flarer, pipe bender, deburring tool, pipe cutter, pipe fittings, replacement hoses, brake fluid, torch, goggles and rubber gloves. As I shall explain, you need way more than this to complete the job, but these are most of the things that are specific to this job alone.


So, get the car up on axle stands and remove the wheels. You're gonna need a fair bit of access here so raise the car as high as you can whilst remaining safe. Support the stands with something soft, as these can give a bit and help maintain even support.


Next, drain the brake fluid. The kit I bought uses air pressure from the spare tyre to pressurise the system. The fluid can then be drained easily through the bleed nipples at each brake. 20psi is the maximum pressure to be used with this kit, so I let some air out of the spare tyre.


Once the system has been drained, I removed the bleed nipples as I had bought replacements from Ford due to them being rather corroded. This was the first of a few instances where all the reading online and research and preparation cannot cover everything. The bleed nipples on the front are much smaller and will have to be reused.


I began by removing the front brake hoses. Whenever you are undoing something old and corroded, try to use a close-fitting tool. I made extensive use of my crows-foot spanner fitments throughout this job. These grip more flats than a conventional spanner. Flare spanners are available, but I made use of these as I had them in my tool kit.


The hoses are clipped into supports as shown in this picture. On a car of my age, they can be a right bugger to shift. I ended up tapping them out with a screwdriver and hammer.


I had tried to loosen the pipe connection but it was so tight, I was scared of damaging the thin mounting point. I decided to cut the brake pipe with a hacksaw as it was to be replaced anyway.


When removing the hose from the caliper, beware of the crap and flaking metal that can and will fall into the threaded hole. I removed these part way, then using a screwdriver and wire brush, cleaned the caliper and hose as best I could before removal.


Once removed, either plug the hole with a spare bleed nipple or make up a bit of pipe like I did. This will ensure no crap gets into the hydraulic system whilst you're busy removing everything else.


At this point I began tracing the pipe back to the master cylinder in the engine bay. Now on some older cars this is quite accessible but not so on the Focus! Getting anywhere near it requires removing rather a lot of engine-bay components, and repositioning of fuel lines, etc. Even with all of that out of the way, it is still a struggle as the cylinder is mounted right up against the top of the firewall. As you can see in this picture, I'm using my trusty crows foot spanner and breaker bar once again. Once you've cracked these loose, you can undo them by hand.


This provided another surprise. Inexplicably, the fitting connecting the front brake pipes to the master cylinder are larger than every other fitting on the system! These too shall have to be reused.


And that is generally how you remove these things. Push as much as you can out of the way, take a mental note of where they run, or take photos as you go along. (It's also a good idea to take photos of everything you disconnect or reposition because it can become a difficult jigsaw puzzle!)

Access as mentioned is incredibly awkward most of the time. This photo shows me undoing the union on the rear brake pipes. The pipes run down the engine bulkhead, feed between the chassis and front subframe, then run the length of the car to the rear. This union is just before the pipes run between the subframe and chassis. There is no room to wield a spanner and requires a creative arrangement of tools to loosen.


In order to completely remove the rear pipes, the fuel tank needs to be dropped (but not disconnected) on one side, and the exhaust heat shield dropped on the other side. The latter requires the exhaust to be dropped and loosening exhaust bolts is very difficult if they are even months old as they seize up and tend to shear. I was close to shearing one bolt, but I found lots of WD40, and gently tightening and untightening saw it come off eventually.

To lower the fuel tank, support it with a jack and undo the bolt holding the retaining strap. Gradually lower it until you have the access you require.


Once the rear pipes had been removed, I disconnected them from the master cylinder. They connect via pressure relief valves and I noticed one of these had signs of leakage around it. Typically it was the hardest one of the two to reach, and required both of them to be removed.


Now, here's a quick 'old vs new' comparison.

Rear brake hoses:


Front brake hoses


Now you should clean up as much as is practical before fitting new components. Once relatively clean, I began by installing the hoses. Try fitting these in a few ways before you find a particular layout you're happy with. Now replace the clips you removed earlier. This can be tricky, as they are very tight fitting and space is extremely limited. Persevere though, it is doable.

Rears:


Fronts:


I then replaced my cleaned up pressure relief valves and tightened then sufficiently to avoid future leaks. Access to these is ridiculously poor, so good luck!


Now the fun part, making new brake pipes! You generally get the pipe coiled up and the ONLY way you are realistically going to get it straight-ish is to unwind it along a flat surface. Don't just pull it out, unwind it!


At this point I decided against using my pipe cutter. It did not cut the pipe square, so I used a little vice to hold it then cut using my hacksaw.


Once cut, use the deburring tool. If at all possible, point the pipe downwards for this so any metal flakes are not left inside the pipe.


Now grab your pipe flaring tool. The tool I bought is the one you want. There are cheaper ones on ebay but they are truly dire. If you want I can explain why, but trust me, if you buy one of these 'deluxe pipe flare tools' you'll get perfect flares every time. Part of the reason is it shows you exactly how much pipe needs to protude from the tools before flaring. This gives consistency to the flares.


Once clamped in place, insert the flaring die into the pipe end and tighten the tool.


If you remembered to insert a fitting before flaring then well done, your pipe end should look like this:


It's up to you how you bend and route your pipe, you'll get a feel for how it should be done. I would like to point out that you should bend the pipe as little as is possible, especially when using copper pipe as it work hardens quite quickly and can become brittle. If in doubt, start again. Your brakes are not worth taking a risk over. Always buy more than you need, as this way you won't feel pressured into accepting something you would rather not use.

When routing the rear brakes, the first thing I did was feed it, from the rear of the car, between the chassis and front subframe. This was so tight, it had to be done with a clean cut end. This picture is taken from the rear looking forward.


Once you see it come through, start bending it upwards, and eventually you'll feed enough through that it emerges from the engine bay.


Using the flaring tool, flare the end ONLY when you've put a fitting on the end!


This can then be carefully fed through to the master cylinder and attached to any clamps the original pipework was attached to. Pull any slack back through the chassis/subframe point, and make a generous estimate as to how much pipe you'll need. Add a comfort factor, and cut the pipe. This can then be fed behind the fuel tank, or above the heat shield as before. Take care to secure the pipe to any clips. This prevents severe vibration, which would otherwise workharden the pipe very quickly, leading to failure. Some of them are hard to reach, but they must be used.


Cut and flare the pipe to the appropriate length when you get closer to the brake. Be careful not to let the flaring tool strain the pipe; support them on something.


Connect everything up and tighten to 'reasonably tight'. Overtightening can damage the flares, put excessive stress on the fittings and possible cause stress corrosion cracking and failure. The copper is soft so should not need to be enormously tight. Any leaks will likely be small; you'd be very unlikey to lose much of your braking power through a leak.

Put everything back in the engine bay, and clean up as far as is possible.


Get your pressurised brake bleeding kit back out. Don't fill it with fluid, but connect it up and pressurise it. Check each union for leaks, which should be audible. Try to move the pipe about to instigate leaking. Upon doing this I found one union I had not tightened much beyond finger tight. You'd much rather discover this with air than brake fluid, and you'd especially not like to discover it while driving....

When you've satisfied yourself the system is air tight, begin filling the system with brake fluid. Fill the reservoir with fluid, and then use the brake bleeding kit as you normally would. The brakes might not seem to need much bleeding, but keep going for longer than you'd imagine. There are probably air locks in the system which take a while to shift. This caught me out as the brakes were seriously spongey when I took it for a drive. A second, longer go at bleeding sorted this.

And that's pretty much it. Just check and double check everything. You have to disturb a lot during this job, and it all needs to go back correctly. I personally found a rattling noise after this which turned out to be the exhaust clattering against the heat shield. Some things are harder to put back in exactly the correct way, but this way easy enough to sort.

Finally, the serious bit. It goes without saying that brakes are an important part of a car. Suffering a brake failure can cause serious harm or worse to you and other road users. The work I did was not especially tricky, but it is fiddly and requires patience, attention to detail and time to complete. It took me 2 1/2 full days to complete, so if you are thinking about doing this, budget for the time and do not cut corners. Take pride in this job, and you will be okay.

PS - You will need a fair few tools for this job. I can't say what because I was constantly dipping in and out of my tools and I seem to have a fair few these days!