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Baker556

Member

• Jul 26, 2021

• #1

Hi All,

After changing the brake lines on the disco, the front left, passenger, nearside caliper is bleeding but only comes out as a trickle when using the gunson ezi-bleed.

The upper rear nipple on the caliper bleeds as expected with a good flow but the front nipple only blobs out.

Is this as expected? Could there be a blockage somewhere in the system?

Finally, does it matter which way around these pipes are connected for the two coming into this caliper I guess these could have been mixed.

Thanks

 

discool

Well-Known Member

• Jul 26, 2021

• #2

If your bleeding the entire brake system nipples on the inner side of the caliper should be bled simultaneously, the lower one is the primary circuit the upper one is the the secondary circuit, the third nipple at the is for the secondary circuit, so front only.
Cross over of the of the pipes is difficult as both run parallel side by side at the rear of the caliper.

Secondary circuit is one piston on each front caliper. Primary circuit one piston on each front caliper plus both calipers at the rear… which I’m sure u know

 

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Baker556

Member

• Jul 26, 2021

• #3

Discool, thanks for taking the time to reply.

No I didn't know all of this information, you mention third nipple is that right? Well as I installed new copper lines I might have crossed them over, should that matter?

Thanks

 

discool

Well-Known Member

• Jul 27, 2021

• #4

Baker556 said:

Discool, thanks for taking the time to reply.

No I didn't know all of this information, you mention third nipple is that right? Well as I installed new copper lines I might have crossed them over, should that matter?

Thanks

Click to expand...

In theory…with both braking circuits, primary and secondary, being correct both pistons in each front caliper will operate simultaneously, so not a problem… in theory.

If unfortunately the primary circuit failed leaving only the secondary which is just a single piston in each of the front callipers, and one pistion is in a leading position on caliper and the other caliper in a trailing position there maybe a slight issue, but still you would have braking, although it’s limited as u would expect anyway.

The Haynes manual may show the secondary pipe run, so u maybe lucky and have the correct pipe in place,
Your system operation is the same as fitted to my old RR, so I’ll look in my Haynes RR manual for a drawing of the pipe layout, its more comprehensive than the disco manual

 

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Baker556

Member

• Jul 27, 2021

• #5

Great, I do have the disco manual now you mention it and will check. Thanks!

 

discool

Well-Known Member

• Jul 27, 2021

• #6

This is all I could find and only from the Haynes RR manual. Nothing for the full pipe work or any T pieces

Also, me forgetting that each D1 front caliper is a 4 pot, I stated above #2 that there’s only one piston for primary and secondary, incorrect theres two pistons of each circuit per caliper… thats one piston on each side per circuit.
Can’t be bother to use ‘edit’

 

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Baker556

Member

• Jul 28, 2021

• #7

Mega useful and thanks for taking the time to upload this Discool.

From the diagram, I can trace back from the MC to the primary or secondary! Thanks again.

 

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Baker556

Member

• Jul 29, 2021

• #8

Discool, the issue was the third nipple, i thought you were joking about this! Tucked around the back, bled through working like a dream, thanks alot!