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Big Disc Brake Conversion - Questions? / Guidance

568 Views 8 Replies 6 Participants Last post by  Raquen
My 1991 Defender 2 door Pickup/Beachrunner has stock front disc and drum rears, Salsibury Rear end, and 18 wheels.
~30K original miles. Very good condition. Middle East truck. I need to downshift and brake to really stop quickly. New(bigger?) brakes are a must.
Looking for guidance to be able to "stop on a dime". I need/want a safer driving experience than I have now. FYI, it's a 4 cyl-Petrol....LS swap forthcoming?

Option 1: New front pads. New rear drum and pads....>>>>>>>>>>>How good will this stock configuration stopping power be?
Option 2: New front pads. Convert rear Salsibury to disc>>>>>>>>>How good will this be for an future LS engine?
Option 3: New front pads. Convert rear Salsiberry to BIG DISC KIT. >>Will this be enough?
Option 4: BIG DISC Conversion Front and Rear. >>>>>>>>>>>>>>>>Clearly this is the ultimate configuration. Which Kit?

With Option 4. Is a master cylinder upgrade required?
Appreciate any insights and experiences.
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Bigger brakes, in and of themselves, don't generally mean more stopping power (some argue that the larger rotor creates more leverage, but it is really negligible). Larger brakes are generally about increased thermal capacity, which means they can provide adequate stopping under prolonged usage, not necessarily a shorter stopping distance in an emergency stop.

Drum to disk conversion in the rear, again, is generally more about increased thermal capacity, as well as easier maintenance, but not necessarily more powerful brakes (and generally the rears can't provide more braking 'power' anyway as it would just be lost locking the tires as weight transfers forward)

Most stock brake systems are capable of locking the brakes, and if they are, going to larger, or multi-piston calipers isn't likely to solve your problem.

Stock rotors, and perhaps a more aggressive pad may achieve the feel you are looking for, or perhaps more power assist is needed?

But before making any changes, make sure the brake system is in good condition.

Is the pedal firm? Fully flush and bleed the brakes, and you may be surprised at the change..
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How about adding anti-lock braking for emergency stopping?
Fix your brakes. They should lock up with normal pedal effort. You need to go through a everything to find the issue. There is no need for any modifications.
Agree with Red. Go with Option 1.

Bleed the whole system. Ensure calipers are functioning, ensure rear drum brake cylinders are functioning. Check that brake booster and check valve on booster are good, and that vacuum line is not cracked.

if you do do pads or shoes, have discs or drums turned.
Mine stops on a dime. I have the Forbyn Brothers HydraBoost Hydraulic booster on mine. I also added rear discs. Rather then convert the Salsibury , I ditched it for a D1 with built in discs. Over all a mutch cheaper option and from my experience yeilds a better results then adding WilWood or the like in front. The stock Defender calipers are already quad piston.

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Great idea with the HydraBoost.
Did use the stock Master Cylinder? How is it plumbed? Any pics? THX
Great idea with the HydraBoost.
Did use the stock Master Cylinder? How is it plumbed? Any pics? THX
the Forbyn Bros pedal assembly alows the mount of a stock hydroboost unit, I believe the recomended model was from an AstroVan. From there you can use standard GM/Chevy master cylinder kits. I will search for any pics. My 110 in the paint shop currently
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