Thread: County Drum rear to disc rear, booster upgrade

Originally Posted by defmec

i have just swapped over the disc rear end into my 85 county and bought a disco brake booster to fit ,but it doesn't need it, the county pulls up better than ever with the original .
why would my county's brakes work great with the standard brake booster but other county's brakes not work?

Did you convert your Salisbury or get a disc rear end complete???
And what is the part number on the sticker on the brake booster you have?? it might have been upgraded to a defender one at one stage...

Dragging up an old thread here, but I've just tried a similar conversion in my County 110 as I'd just completed a rear disc conversion, and had been having issues with my County booster and M/C.

I'd previously bought a pedal box and booster from a '94 Defender, but when I found the booster was cracked (normal place next to the M/Cyl mounting studs) I thought I'd give a D1 booster a try since I had a couple sitting around (as you do )...
Rather than butcher the County one, I set up the Defender pedal box, booster and M/C in the shed, then did a complete swap with the County setup. Mainly in case it had any issues and I needed to swap back.

Together with the rear disc conversion, the braking is like....well....a Disco
The improvement in braking power and feel compared to the drum rear with County booster + M/Cylinder is amazing. Definitely glad I did it.

Unfortunately, the Defender pedal box and Disco booster isn't a perfect match dimensionally. The input rod on the Defender booster is ~112mm from mounting face to the center of the fork pivot bolt, whereas the Disco booster is ~98mm.
This means that with a Defender box and Disco booster the brake pedal is held forward by the booster rod and gives you a lower pedal position, but more problematic is that the brake pedal doesn't come all the way to the rear of the box to actuate the brake light switch. Since it sits around 15mm forward there's no easy way of getting around it.

The good news for us County owners, is that the County booster has the same input rod dimension as the Disco one, so the County pedal box with Disco booster is a perfect fit match apart from needing the pivot pin hole drilled out slightly larger, and mounting holes modified as detailed in the original post.
I'll be swapping back to the County box.

Its a pity I don't have a working defender booster here as it would be very interesting to compare the difference in braking between the defender and disco ones. As a side comment, the defender boosters are like tinfoil compared to the Disco ones. No wonder they fatigue crack like they do.

Sclarke - many thanks for the original post.

Steve

I wonder how clarkie is going in his " Das auto ", he's been a bit quiet on here.

One other useful bit of info....
The M/C I used is from a ABS D1 (P/N: STC1284??).
It was the easiest D1 M/C to fit to a County, as it only has 2 ports so you don't have to stuff around blanking unused ports etc.

Steve