Brake Pipe Routing

Does anyone have a diagram for the brake pipe routing on a 300tdi disc brake all around?
I have a new master cylinder and new bias valve and just need to know which ports from the master feed which ports on the bias valve, and then which ports one the bias feed front and rear.
I am happy with the pipe routing around the chassis to the wheels once I know which ports to use. My parts manual (below) only goes up to drums on the rear and I have discs. Is the routing the same as the below?

That’s how I routed mine. Also from drum to disk.

Hicap phill said:

That’s how I routed mine. Also from drum to disk.

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Great many thanks, front of master to front brakes seems easy enough. Is the bias valve handed or does it not matter as it is just as it is just a shuttle valve for if you get a fluid leak?

Yes the valve is handed. Big nut towards the passenger side, back brake is close to this.
Make use you plumb it up right otherwise you lock the rears before the fronts

dag019 said:

Does anyone have a diagram for the brake pipe routing on a 300tdi disc brake all around?
I have a new master cylinder and new bias valve and just need to know which ports from the master feed which ports on the bias valve, and then which ports one the bias feed front and rear.
I am happy with the pipe routing around the chassis to the wheels once I know which ports to use. My parts manual (below) only goes up to drums on the rear and I have discs. Is the routing the same as the below?


View attachment 271390

Click to expand...

That's the same as a classic Mk3 Mini
My 1990 90 pipes went across the bulkhead to the N/s disc and along the off side chassis rail to the flexi to the rear axle, Bias valve was on chassis under bulkhead on off side and was inline
That mini type bias in diagram is also a shuttle valve as you said in case of a leak

The Manual I have (1996 300tdi) shows that no PRV (bias valve?) is fitted on the 110 with discs.

J

marjon said:

The Manual I have (1996 300tdi) shows that no PRV (bias valve?) is fitted on the 110 with discs.

J

Click to expand...

Mmmm
Must have a different master cylinder on the later models to cope with bias?

Well I didn't get very far as I ran into some issues. The first one being the master cylinder (LR013018G) I have is different to my old one and has three ports coming out of it. Two at the front and one at the rear (pic form google)


The second issue I have is that the bias valve I have looks like it doesn't come with the fittings the old one has? Do I need these to connect the brake pipes up, or is it designed to use male fitting directly into the valve body? I am going to guess they will not come out of the old one so does anyone know what it is that I need and I will get a pair ordered.



And lastly if I have three ports on the master I assume I am piping it up similarly to the diagram provided by @marjon and do not need the bias valve at all?

Well I Made some progress plumbing in the brakes today, I am following the diagram without the bias valve so have got the rears all connected up, I then ran into a couple of issues with the fonts, firstly one of the brake pipe brackets on top of the swivel pin snapped so need to get a replacement on of those, and secondly the new flexi pipes do not come with nuts! Am I expecting too much for quality (delphi) parts to come with everything required to fit them? The clutch flexi I have just fitted did.

dag019 said:

Well I Made some progress plumbing in the brakes today, I am following the diagram without the bias valve so have got the rears all connected up, I then ran into a couple of issues with the fonts, firstly one of the brake pipe brackets on top of the swivel pin snapped so need to get a replacement on of those, and secondly the new flexi pipes do not come with nuts! Am I expecting too much for quality (delphi) parts to come with everything required to fit them? The clutch flexi I have just fitted did.

View attachment 271685

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Funny thing is I have some P38 front flexi hoses sitting waiting to go on (britpart) and they come with all the brackets, banjo bolt with copper washers and even the clip. Others makes dont.
Did you read those instructions There's a line in there that says you will need some new nuts.

Not really.
Will be interesting to see if you notice any diff in braking doing it without the bias valve.

J

marjon said:

Did you read those instructions There's a line in there that says you will need some new nuts.

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Absolutely not, I took them out of the box, ignored the piece of paper, shook the box some more expecting nuts to fall out and they didn't! Managed to work out I would need some all by myself

dag019 said:

Absolutely not, I took them out of the box, ignored the piece of paper, shook the box some more expecting nuts to fall out and they didn't! Managed to work out I would need some all by myself

Click to expand...

At least with blue bag stuff you can see your nut error even quicker

No bias valve could lock the rear brakes quicker

Hicap phill said:

No bias valve could lock the rear brakes quicker

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I thought that. But as I previously had not changed the bias valve from the one used with drums when I upgraded to discs I guess it should be the same or better. The master cylinder has to be designed to be used without it if that is the official plumbing for the 110.110 rear callipers are larger than a 90 so makes sense to need it for a 90 as they would lock very quickly with small diamiter pistons.

Hicap phill said:

At least with blue bag stuff you can see your nut error even quicker

Click to expand...

If it was a blue bag I wouldn’t have been expecting it to come with nuts!

Many thanks all for all the help. Other than awaiting the pipe bracket on top of the swivel pin the brakes are complete and plumbed in. As soon as that arrives I can do the last pipe and bleed them though.



One last question regarding the brakes, the disco engine I am using had aircon so does not have a suitable servo to vacuum pipe. I am assuming it is just a piece of reinforced rubber hose, does anyone know what size I need to buy?