Dual circuit remote servo - help!

Dual circuit remote servo - help!

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e21Mark

Original Poster:

16,481 posts

188 months

Monday 11th March 2013
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I am upgrading the brakes on my old e21 BMW and I want to lose the linkage that BMW use to get around moving everything across to the right side. The linkage just allows too much play and loss of pedal pressure so I want to ditch it altogether. The problem is that I can only find one remote servo that works with dual circuit brakes and it's nearly £300.

I'm running Sierra Cosworth 4x4 front brakes and 323i rears, with an e12 535 master cylinder but could I run a servo on the fronts only? (or is that a stupid idea?)

Any help or advice would be much appreciated.

V8covin

8,543 posts

208 months

Saturday 23rd March 2013
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I only know of 1 servo like your're suggesting and I'm guessing it's this one http://www.s-v-c.co.uk/product/dual-remote-servo/

Running servo on just the fronts isn't a wise move...... you can use 2 remote servos .....alternatively ditch the servos and go for a bias pedal box

stevieturbo

17,781 posts

262 months

Saturday 23rd March 2013
quotequote all
Surely the "dual" part is in the master cylinder, and not the servo ?

The servo only provides mechanical assistance to a piston, so is always a single actuator.

Or another option...could you use the Sierra's electrical pump setup ?

Mr2Mike

20,143 posts

270 months

Monday 25th March 2013
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stevieturbo said:
Surely the "dual" part is in the master cylinder, and not the servo ?

The servo only provides mechanical assistance to a piston, so is always a single actuator.
Check out the link above, it's a remote servo with a dual circuit master cylinder. Thus you'd have the dual circuit master cylinder attached to the pedal box, with two pipes leading to the dual circuit master cylinder on the remote servo, and then onto the calipers/slave cylinders.

The vast majority of remote servos are single circuit, so you'd need two of them which is exactly how some of the older Alfa brake systems were arranged.

Another option is to use a standard pedal actuated servo/master cylinder unit, and modify it to be actuated from e.g. a clutch slave cylinder. This means you have a vast choice of servo units, with the downside that you now have a single circuit between the pedal and the servo, which means no brakes if it fails.

e21Mark

Original Poster:

16,481 posts

188 months

Friday 29th March 2013
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I bit the bullet and went for the SVC servo. They reduced the cost a bit for me too.

roysum

961 posts

204 months

Tuesday 28th April 2020
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I know this was a long time ago but wondered how you got on with this remote servo ?
Hating the present servo setup with all the linkage etc.
Have you still got the car ? wondered if you could take a couple of pictures.
Many thanks, Roy.

1602Mark

Original Poster:

16,481 posts

188 months

Wednesday 29th April 2020
quotequote all
It worked perfectly and the E21 brakes were loads better for losing all that RHD linkage. I would certainly use another if needed.

https://forum.retro-rides.org/thread/68744/project...