Disconnecting the brake line from the brake cylinder

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muhnkee_2
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Disconnecting the brake line from the brake cylinder

Post by muhnkee_2 »

Hey folks,
I am in the process of replacing my rear brake cylinders, following lots of tips on the forum. But i am facing a problem that others have not mentioned, though i can loosen the brake line from the cylinder, i cant get it out. Picture attached.
I have loosened the back plate and got the cylinder loose and free, but i cant seem to get the end of the brake line out.
I dont want to force it too much for fear of bending the brake line.
Is there anything i am missing?
Also when i get it loose, how do i seperate the brake bleeding part from the cylinder, will it just come out, i cant see any thread on my replacement cylinder.
Thanks a lot - as usual!
Cheers,
Greg[frame]Image[/frame]
Kevin the globe trotting 1956 two door

bmcecosse
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Re: Disconnecting the brake line from the brake cylinder

Post by bmcecosse »

The flared end of the pipe will have 'swollen' and will be catching on the threads - you need to wiggle and PULL... The picture shows the part your brake pipe is screwed into has a hex - just unscrew this and the 'banjo' with the brake nipple comes away. There MUST be a thread in the new brake cylinder !
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muhnkee_2
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Re: Disconnecting the brake line from the brake cylinder

Post by muhnkee_2 »

Thanks BMC, i wiggled and jiggled and got it out, now the next challenge, to separate the brake pipe and banjo. I have spray liberally with WD40 and will give it some time to loosen up!
Thanks a lot.
Greg
Kevin the globe trotting 1956 two door

bmcecosse
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Re: Disconnecting the brake line from the brake cylinder

Post by bmcecosse »

It's usually well lubricated with brake fluid...use a ring key - not an open end spanner......
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philthehill
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Re: Disconnecting the brake line from the brake cylinder

Post by philthehill »

Unless your brake pipe is covered in crud and not rust as it appears to be in your photo it should be replaced. If you are going to replace it cut the pipe, remove the pipe nut which will give you more wiggle movement. If the pipe still will not come grip the brake pipe in a vice and gently tap the adapter which fits into the rear of the brake cylinder. I agree with bmc that the pipe flange nipple has distorted when it was tighten up (a common fault) and which is now causing difficulty in removing it from the adapter; again I would advise fitting a new brake pipe as the pipe may be stressed in the area of the flange nipple.
I would also advise against reducing the diameter of the old flange nipple to allow the pipe to be re-fitted into the adapter.
When fitting new brake pipes use ones made from Cunifer metal.
As regards spanners for use on brake pipes the best ones are the special hexagon 'C' spanners which fit over the pipe and are strong enough to undo the brake pipe nut. They are available from all good car accessory/parts shops. It is the one spanner I would not be without.

bmcecosse
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Re: Disconnecting the brake line from the brake cylinder

Post by bmcecosse »

The brake pipe does look well past it's 'use by' date! Kunifer IS THE ANSWER! Never need to worry about it again..... :)
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muhnkee_2
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Re: Disconnecting the brake line from the brake cylinder

Post by muhnkee_2 »

Thanks for all the information, i feel like i am unpeeling a many layered onion here!
I wasn't planning to replace my brake pipes, and i have managed to get the brake pipe separated, so am i OK to leave the brake pipes in place and replace all the brake cylinder parts (including banjo and washers), or am i just fiddling while Rome burns as they say?
Should i being doing a whole replacement of the entire braking system?
Thanks again!
Greg
Kevin the globe trotting 1956 two door

les
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Re: Disconnecting the brake line from the brake cylinder

Post by les »

Do you feel lucky? As someone said. Once you know a brake pipe is dodgy, it's not easy to forget it. :o

dalebrignall
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Re: Disconnecting the brake line from the brake cylinder

Post by dalebrignall »

all i will say is your brakes have to be reliable and safe
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philthehill
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Re: Disconnecting the brake line from the brake cylinder

Post by philthehill »

Interestingly there are two spellings of the type of metal used for brake pipes Cunifer and Kunifer. Both are used for the same product. I have checked the name on my spare roll of brake pipe and it is Kunifer which may be the trade name.
If you Google Kunifer it comes up with Cunifer so use of either spelling is correct :D

muhnkee_2
I would urge you to replace at least the brake pipe shown in your photo for the reasons given above.
My considered opinion as an ex vehicle examiner and ex MOT examiner is that no sensible person in their right mind is going to say it is alright to re-use.
If the other brake pipes are just as bad they should be all replaced.

bmcecosse
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Re: Disconnecting the brake line from the brake cylinder

Post by bmcecosse »

I agree - that pipe looks pretty rotten - it would be a shame to do all the work, bleeding the brakes - for it to be failed at MOT...or worse, to burst in service ! A roll of Kunifer and a brake pipe flaring kit is a very good investment. http://www.ebay.co.uk/itm/IMPERIAL-PIPE ... 4d08efb4ba
The alloy used contains Copper (Cu) and Nickel (Ni) and Iron (Fe) - the name I have seen is Kunifer but obviously Cunifer is the same thing. It's not so easy to make the flares with Kunifer as it is with normal Bundy pipe - just put a spot of brake fluid on the pipe when flaring it to make the job slightly easier. Don't be tempted to use 'copper' pipe!!
http://www.ebay.co.uk/itm/Cupro-Nickel- ... 51a4bdc3b3
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StaffsMoggie
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Re: Disconnecting the brake line from the brake cylinder

Post by StaffsMoggie »

Copper pipe is quite unsuitable. It can fracture very easily. Cupro-nickel is the stuff to use without any doubt!
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