Not sure if I have used the right term there in the subject, but I am referring to the lines that run along the length of the car (underneath).
I had an advisory on my last MOT that said “brake pipes starting to corrode”, and like a fool I rushed out and bought a new copper brake pipe set and started replacing them. However, what I did not realise, and obviously neither did the MOT tester, was that of the four lines running down the length of the car, only one was a brake line. Whilst I have found a few bits of surface corosion on the brake lines here and there, it was clearly the other lines that the MOT tester was referring to.
Am I right in saying that those other three lines are all fuel lines? And if so, why three? What is connecting to what?
How should I go about finding replacement parts? Are they generic? Couldn’t see anything on mx5parts, unless I am searching for the wrong thing.
Are you certain only 1 is a brake line, I would have expected a diagonal split system so 2 lines, one to each rear wheel. For the fuel tank it may have a supply and return.
Fairly sure, I am replacing all the rigid brake lines at the moment, and I believe there is just the one line running down the length of the vehicle to a distribution block at the rear, which in turn splits and goes to each rear wheel.
Numpty question I’m sure, but why does the fuel tank have a return?? Fuel that is unused by the injectors? Why might a third line be required? Anything to do with the charcoal chamber? (not sure I really know what the chracoal chamber is for if I’m being honest, I assume something to do with filtering out vapour or fumes as it’s charcoal, but no idea why!).
These questions are only for interest and a better understanding at the end of the day, my main concern is getting these coroded lines replaced!
OK, I’ll do some proper research in future before posting.
It would appear that the charcoal chamber is not really that important, and that more than one configuration exists. On my car it is most likely that this third pipe comes from the charcoal chamber, and is open ended at the other end like a little exhaust (as Wayne put it). But how do the other two lines come into play?
As I said before though my main concern is getting these lines replaced!
Really sorry to bump boys and girls, but I would like to get this sorted this weekend, weather permitting.
Where can I get replacement fuel hard lines? Is it a generic product, or is there something specific for the MX-5? If a generic product is required, anybody know the internal diamter?
Thank you. Just wanted to exhaust every possiblity before I did that, my local Mazda dealer never returns my calls weeps
I did get through to somebody this time though, a shade under 50 quid each for the supply and return, and 35 for the vapour/charcoal chamber one. Seems very expensive, but what choice do I have. Think I will get rid of the charcoal chamber altogether and try to save my pennies.
One is high pressure fuel from the pump to the engine. When it gets there it feeds in to the fuel rail. On the end of the fuel rail is a fuel pressure regulator which bleeds off excess pressure to the return line to the tank. That’s why there are two pipes.
Thanks Geoff, that’s a good idea, I’ll call round and get some quotes this afternoon.
And thank you Captain Muppet, that makes sense.
I have to take back what I said in my first post, regarding the MOT test centre getting it wrong - the brake line that goes from the block to the other rear wheel was in a bad way. So that’s what they were talking about.
Going back to the fuel lines, there are still a few places where I can see a small amounts of surface corrosion, which are easily exposed with a little bit of a scrape from my finger nail. I’m assuming the advice would be not to leave it? Not sure why I’m even asking this, it carries fuel, I should definitely replace them if in doubt, lol. I’m just so skint at the moment
All this very much depends on what you classify as corrosion. It is quite rare, in my experience, for a brake or fuel line to go from zero (no MOT advisory) to failure in 12 months, unless you are doing serious miles in very harsh conditions.
You are doing the right thing by replacing the lines that are corroded as per the advisory, however if there is no advisory then you don’t really need to replace them.
A decent motor factors will make up any brake or fuel line you need, as above take it off and take it in, they will make it up. Pretty much anyone other than Halfords will be able to do this, and even Halfords may be able to do it. However, once it is off, and if you have the right kit (which is very cheap), making brake and fuel lines isn’t difficult - if the apprentice at a garage can do it, you can do it.
I wouldn’t replace all the brake and fuel lines based on an advisory on an MOT. Whenever my car goes in for MOT if there is an advisory or fail I ask them to show me. That way you can see what has failed or is in bad condition, and rectify what needs doing. Obviously if you are replacing some components then they need to be done in pairs - suspension etc - but just because your rear brake lines are corroded, doesn’t mean your front lines will be - being rear wheel drive corrosion typically happens at the back more than the front due to salt, grit and water on the roads, especially around the wheels and arches.
I’ve pretty much done all the brake lines now. I bought the kit off mx5parts.
I hear what you are saying with regards to replacing things unnecessarily, and I’m sure the car isn’t going to explode in a ball flames any time soon, I just thought that where there is surface corosion, soon there will be heavy corosion, and change it before it happens, especially as it’s fuel we’re talking about here. I don’t know. Maybe I’ll leave it for now then.
If it is just surface corrosion on the fuel pipes, then clean it off and check the condition of the metal underneath.If the rust has deeply pitted the metal, then a replacement tube will be required, but if the rust can be removed easily and the remaining metal looks OK then ‘rust proof’ the cleaned up areas and paint the pipes. You now have some experience of how bad the corrosion must be for a brake pipe advisory to help you make an assessment of the fuel pipes.<o:p></o:p>
I cleaned off the surface rust and rust-converted. The pipes didn’t need changing; as you said Nigel, I’ve seen how bad it has to get for it to be an advisory. They should be good for a few more years to come, thank you all very much for the advice.
