Single Circuit master cylinder

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Rob-type3
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Joined: 22nd April 2018 - 11:40am

Single Circuit master cylinder

Post by Rob-type3 » 22nd February 2020 - 12:13am

I believe I need to replace mine on my 64.

Is there any others that fit? I keep seeing Ghia ones they look the same and possibly beetle?

Any help would be great! I’m wanting to keep it all drums all around so I know options are limited.

Cheers Rob
1964 Notchback
1970 Fastback

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sparkywig
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Joined: 28th August 2013 - 12:49pm

Re: Single Circuit master cylinder

Post by sparkywig » 22nd February 2020 - 12:26am

Why not fit a dual circuit master cylinder?

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Rob-type3
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Re: Single Circuit master cylinder

Post by Rob-type3 » 22nd February 2020 - 12:40am

sparkywig wrote:
22nd February 2020 - 12:26am
Why not fit a dual circuit master cylinder?
From what I’ve been told is I can’t run drums on a dual circuit
1964 Notchback
1970 Fastback

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sparkywig
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Re: Single Circuit master cylinder

Post by sparkywig » 22nd February 2020 - 9:12am

Yes you can, but you need to swap the brake fluid reservoir for a dual chamber one.

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937carrera
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Location: North Yorkshire

Re: Single Circuit master cylinder

Post by 937carrera » 22nd February 2020 - 9:25am

Here's a link with the part numbers - unique to type 3 and type 34 by the looks of things

http://www.type34.com/forum/mechanical/ ... build-kits

Mecatechnic have them in stock, sit down while you look at the price
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

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Rob-type3
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Re: Single Circuit master cylinder

Post by Rob-type3 » 22nd February 2020 - 12:59pm

sparkywig wrote:
22nd February 2020 - 9:12am
Yes you can, but you need to swap the brake fluid reservoir for a dual chamber one.
So just run a dual cylinder and a dual tank then so many said you can’t run drums on dual so annoying
1964 Notchback
1970 Fastback

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purplepeter
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Joined: 8th August 2006 - 4:41pm
Location: Bath, Avon

Re: Single Circuit master cylinder

Post by purplepeter » 22nd February 2020 - 2:03pm

As already said, Your best bet is past parts, who will sleeve & rebuild your cylinder to the original bore
I probably have the rebuild kit, ( bag full of nos components, but you need to strip & measure what you've got) But, the chances are that your cylinder is knackered anyway, so not much point trying to rebuild.

https://www.werk34.de/en/hauptbremszyli ... 021-a.html
http://www.pastparts.co.uk/

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sparkywig
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Re: Single Circuit master cylinder

Post by sparkywig » 22nd February 2020 - 3:08pm

I don't understand why you've been told you can't run dual circuit master cylinders on drum brakes.

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purplepeter
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Re: Single Circuit master cylinder

Post by purplepeter » 22nd February 2020 - 5:35pm

Twasn't me that told him, but probably because of the residual pressure question

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sparkywig
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Re: Single Circuit master cylinder

Post by sparkywig » 22nd February 2020 - 5:52pm

Pre '71 buses run dual circuit master cylinders on drum brakes, when you fit a disc brake conversion you remove the residual pressure valves to stop the discs binding.

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purplepeter
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Re: Single Circuit master cylinder

Post by purplepeter » 22nd February 2020 - 6:33pm

And 70's beetles had drums all round & much the same instruction, so maybe Robins answer might be to fit a dual circuit cyl & add a rpv to the front line, though I suspect it might not make a lot of difference.
But I'd encourage him to check the bore of the 2 cyls first
He could also try proactively messaging people like Simon Kelley, Larry Collins & Paul Dickenson, all of whom are the most likely people to be sitting on a nos single circuit cyl.

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