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Brake Booster removal in a 140

Barracuda_82

Member
Joined
Nov 9, 2015
Location
Sweden
I removed the brake booster on my '70 Volvo 142 and I'd like to replace this with a smaller master cylinder. I'd like to have some more room for the B230 engine and GT30 turbo.

I am going to customize all brakelines, calipers, discs, etc. and I'd like to get rid of that huge obstacle in the engine bay.

Can I replace the booster with a big master cylinder? Or will the brakes become too hard to operate? And if so: has anybody done this before and what are their experiences?

Or is it wiser to invest some money in a "stand alone" pedalbox?

Keep in mind: the car isn't going to be a road-car. The purpose is to hoon and drift it, so it doens't have to be comfortable and I like some above average feel in the pedals.
 
I did a similar thing in my Skyline a few years ago. Dual master cylinders with remote balance adjustment on a custom plate where the servo and master cylinder were, and a remote servo on the front circuit. One could have a single direct acting cylinder of the same diameter as stock, and mount a remote servo acting on both circuits remotely. Removing the servo from the equation altogether may well give either an entirely unacceptably heavy pedal with a large bore m/c or ridiculously excessive pedal travel with a small bore m/c. Remote servos were commonly fitted to 5 series BMW's many British Leyland cars like MGB's and stuff and are available new still, in various effort boosting ratios (diameter mainly covers their effective ratio). Race cars get away with no servo by having huge calipers and large diameter discs, so hydraulic force required is much less than with normal sized road car brakes designed around a servo booster. The pedal ratio is also quite different to that in a road car. beware floor mounted pedal boxes, the length of one's foot limits effective pedal leverage ratio, top mount ones are usually more adaptable, leverage wise.

As an aside, those with an unacceptably heavy clutch or a gammy left leg could look at the Nissan Skline R32 and R33 GTR clutch master cylinders which have a built in mini servo booster. Or even a remote servo. I did a remote servo clutch set up for Peter Stringfellow, the night club owner, who has a gammy left leg, in a Renault 5 Turbo II (mid engine homologation special). they have a very heavy twin plate clutch as standard and when done one could press the clutch with a finger.


http://www.chriswilson.tv/bias_brakes/bias_brakes.html

http://www.chriswilson.tv/bias/bias.html

http://www.chriswilson.tv/bias_brakes2/bias_brakes.html
 
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Thanks a lot for this info, Chris! Much appreciated!

I even didn't know remote servo's existed :p

The remote booster I found on this website: http://www.carbuildersolutions.com/uk/compact-dual-circuit-remote-brake-servo (one of the first hits in Google, haven't really looked into it) is nice. It's not too expensive and small (13,8 cm x 38 cm).

0024880_compact-dual-circuit-remote-brake-servo.jpeg


So if I understand correctly the best (and easiest) solution would be to mount to original master cylinder on a bracket on the firewall, place the remote servo somewhere suitable and run brake lines from that to the wheels.
 
Yep, that's the idea. To retain a similar pedal effort with the same master cylinder you have now, and the same brakes, choose a remote servo of similar diameter to the stock one unless the effort boost ratio for the stock one is published somewhere? the diameter is a big factor in the boost ratio.

This is the type I commonly use from a UK Ebay seller:

http://www.ebay.co.uk/itm/MG-NEW-LO...hash=item5d55319c16:m:mNcssXBluq6t48HzBBcRP8Q


Note it's for s SINGLE line system which may not suit your application. On the Skyline the rear brakes were able to work with no servo assist, the front circuit *only* had servo assist (my rear calipers had large diameter pistons on big diameter discs, the fronts smaller pistons, and I could also fiddle with the relative sizes of the twin master cylinders and the bias bar). You can, like BMW commonly did, fit TWO servos, one for each circuit, or a single dual circuit type.
 
Isn't it possible to use a single servo and split the system after the servo with a brake proportioning valve?

I am also planning on using bigger diameter discs and bigger calipers. I am in the process of figuring out if I could use a used pair of caliper from an Alfa 166 V6. These are 4-pot Brembo's with 305mm discs. Also on the rear axle.

That way I keep it simple and cheap. These calipers sell for around 250 euro's per pair (used ofc) and fabricating an adapter bracket shouldn't be too difficult.

IMG_4388s.jpg
 
Selling what? Adapters for those Alfa calipers?

If so: do you still make and sell them? and which discs did you use with these calipers?
 
I have an 84-88 Dodge Colt booster and master on a modified stand off, on my 140 16V upright conversion. Cylinder diameter and booster area play off against each other at the expense of a slightly mushy pedal. Mushy is probably too negative a word, it works.
 
I have an 84-88 Dodge Colt booster and master on a modified stand off, on my 140 16V upright conversion. Cylinder diameter and booster area play off against each other at the expense of a slightly mushy pedal. Mushy is probably too negative a word, it works.


Bringing this back from the dead.
Any other remote boosters or swaps to make room for poulrais's motor.
Made a plant stand out of my 140 brake booster and need brakes.

This;
RKVdVBM.jpg




Goes in here;
RDyJYJb.jpg
 
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