16 replies to this topic

[L.Hurst]

Hi there

Am about to tackle the task of re designing the brake pipe lines. I am going to run the pipes through the car.

Basically i am unsure of what is the best set up, as Ive read loads of threads on here about diagonal set ups and front and back set ups. So which is better and why?

Also what do I need in the engine bay?

Brake servo (or not?)
Brake master cylinder?
Brake limiter value?

I would like the best set up as I am running a 1380 engine with 4pot set up.

Also any photos of where and how people have run there lines under rear subframe would be great.

Pics tell a thousand words!!!!!

Thanks

[L.Hurst]

No one?

[Waffs1984]

I did my rear subframe brakelines last night!

I'm running the Goodridge stainless hoses front and back. The rear hoses replace both the original rubber pipe and the small length of copper that goes to the subframe mounting point so it simply goes from drum to subframe.

From here i ran a small length from the braided hose along approx 25cm then up through a hole in the rear seat, then this bends to go to the centre of the rear seat. Obviously the same goes for the other side.

In the centre of the rear seat i have the t-piece (like it was standard) with both rear pipes coming in from the sides. The pipe to the front goes along to the edge of the seat and down by the ashtray thingy all the way to the front of the car where i had to put in a join just before it passes through the bulkhead. The reason for this was the impossible shape/size of trying to do this all in one piece!

Once the pipe passes through into the engine bay it bends 90 degrees towards the drivers side and up to the valve situated on the bulkhead just below the master cylinder.

Apologies for no pics - it was late when i finished last night, but i'll try and get some later today for you...

Edited by Waffs1984, 11 November 2009 - 10:02 AM.

[jaydee]

I'd just add that a brake servo isnt really needed, it only makes your pedal less heavy but doesnt give any real brake improvement, it weighs a lot and take a lot of space in the engine bay.

[benjy_18]

if your still wondering what set up to use (front to back diagonal split etc) id say diagonal split if your just road driving if not and your racing it use front and rear plit.

diagonal split systems are designed so that if one half of the system fails you can stil brake in a straight line because you have front left rear right working or opposite, so theres braking on both sides of the car.

if racing use front to rear split because you can adjust it with a pressure valve on the rear brake linesso you stop locking up.

hope this helped

[Dan]

diagonal split systems are designed so that if one half of the system fails you can stil brake in a straight line because you have front left rear right working or opposite, so theres braking on both sides of the car.

It's not, it's so that there is always one front brake working in a failure. To take advantage of the improved braking available from the front. Except that it completely overlooks the massive difference in braking effort between the front and rear which in a part failed diagonal system translates to a massive difference from one side to the other, resulting in a mssive drag to one side when braking on a part failed system. Diagonal split is an awful system in a Mini, there simply isn't enough braking effort at the rear to make it safe in a failure. Stick with front/rear, or if you have split circuit front brakes (twin leading shoe drums or Metro calipers for example) you can make a slit diagonal system which is very safe indeed. Make sure the master cylinder is compatible with the system.

Avoid excessive lengths of flexible hose in the system if you can. Many people find it gives a soft pedal if there is too much flexible length, although with proper spec braided hose it's less of a problem than with a rubber based hose.

it weighs a lot

It's a box of nothing!

[Cooperman]

Whenever brake piping is discussed I repeat, and repeat, the old waqrning. The connections to the brake bias valve mounted on the front bulkhead are METRIC threads, whereas all the other brake union connections are Imperial. Stupid, dangerous, but true. Only Rover could do something as stupid as this (or, maybe, Citroen if you gave them the chance)!

[Waffs1984]

Whenever brake piping is discussed I repeat, and repeat, the old waqrning. The connections to the brake bias valve mounted on the front bulkhead are METRIC threads, whereas all the other brake union connections are Imperial. Stupid, dangerous, but true. Only Rover could do something as stupid as this (or, maybe, Citroen if you gave them the chance)!

Bl00dy hell that is stupid! Thanks for the heads up - i have that piece to do later on tonight, might have to hang fire until i get a metric fitting...

[Cooperman]

Yes, arguably the most stupid piece of automotive design engineering ever and on a safety-critical system as well.
Just take care that you have the correct union fittings. Unfortunately, if you do try to put imperial unions into the metric threaded holes on the valve, the pipes do appear to fit. They just leak fluid when you try to bleed out the system. What happens then is that you see the fluid leak and try to tighten up the unions believing that the fluid leak is because the unions are not tight enough. Then you will strip the threads on the unions and have to buy complete new pipes and run them front to rear. I had to correct this on a Cooper 'S' for a guy only last year. Someone had bought a kit of brake pipes, imperial unions, and tried to fit them to a dual-line system with which the Cooper was retro-fitted.
I used to work on aircraft design and if I had mixed threads on a safety-critical area I would have been sacked. I guess the Rover designer got a bonus for saving money by using a metric-threaded carry over part from another model range.
No wonder they all went down the toilet.

[mark gillan]

Sorry to butt in now but the 2 outlet pipes on brake master cylinder one on top and one below it, does it matter which way they are connected if doing a split front rear brake system, like top for front, bottom for rear or does it make any odds? also the valve on the bulkhead, if this is not fitted as it's not to my clubman what difference would it make?

[Waffs1984]

Sorry to butt in now but the 2 outlet pipes on brake master cylinder one on top and one below it, does it matter which way they are connected if doing a split front rear brake system, like top for front, bottom for rear or does it make any odds? also the valve on the bulkhead, if this is not fitted as it's not to my clubman what difference would it make?

I'm not sure about the first part of your question, but i assume the fronts and rears have to be connected to the correct ports.

In answer to your second part, if you do not have one fitted you will be getting the same braking effort (fluid pressure) to both the front and rear brakes which is not a good thing. The rears need to be proportioned down so that they do not brake as hard, the fronts see the majority of braking effort due to the weight transfer of the car forwards under braking conditions.

I was wondering about this, if you did take it off you would need to put a brake bias valve inline with the rear pipe and set this up accordingly. In fact i may do this and rid myself of the valve altogether (unless somebody comes along and says its really not a good idea!)

[Waffs1984]

Just some pics i took last night of my brake line. Please ignore the fuel line (its not been secured in place as of yet!) and the general mess in there lol!

[Wil_h]

Chuck away the rubbish biasing thing fitted as standard and run the lines direct from the master cylinder with an bias valve in the rear line.

After much debate I run the bottom line to the rear and top to the front.

[L.Hurst]

Great pics!!! thanks for that!
I really like how you have come out to hole and put the T peice in the middle of the back seats, looks great. As I was thinking of putting it underneath before coming into the cabin. So I may change my mind now.


Wil_h - What do you mean chuck away the bias fitting valve?

So If I was to get a bias valve would I run that at the rear on the single brake line which goes into the T peice???

[Waffs1984]

Great pics!!! thanks for that!
I really like how you have come out to hole and put the T peice in the middle of the back seats, looks great. As I was thinking of putting it underneath before coming into the cabin. So I may change my mind now.


Wil_h - What do you mean chuck away the bias fitting valve?

So If I was to get a bias valve would I run that at the rear on the single brake line which goes into the T peice???

Yes it needs to go somewhere on the line going to the t-piece. You could locate it there, but generally you would have it further forwards so it could be accessed from the driving position. I found a brake bias valve on ebay for a reasonable price, i may go for this and get rid of the OEM valve as wil_h suggested.