County Drum rear to disc rear, booster upgrade

[sclarke]

Guys,
Some of you are planning or doing a Disc rear end in your 110 or 90

Well the problem i struck was after the disc rear end was put in the damn county would not stop.... it was terrible...

Now i have a fix... 2 options
1. Buy a 94 MA Vin onwards Defender pedal box, booster and master cylinder. Then plumb it into your situation. Note, my Defender i had was a 3 pipe master cylinder. Countys are 2 pipe.

2. This is what i did.... Alot cheaper.
Pull your pedal box out and booster and master cylinder.
Get a solid disc front Disco master cylinder and booster from a MA Vin onwards Disco
Cut and drill and dremel and file and curse and swear and presto....

Seriously...
I found the match up was nearly perfect..
What i found and what i did...
the Disco booster is the same width and its longer than the county one, but the master cylinder is shorter so it all fits.
The disco booster brake pedal plunger is 5-8mm shorter, but LR in its wisdom made a spacer up that when removed is the same length... Tadddaaa..... its just bolted between the booster and bulkhead on the disco, so discard it.
Use it as a template to drill the 2 holes that the bolts pass thru on the Defender/County brake pedal box your about to modify.
https://www.aulro.com/afvb/images/imported/2009/07/1019.jpg

Then you will find the bolts will not have enough clearance to fit a nut as the thread is level with the plate.
I drilled out 3 holes along side it and dremeled it out.
https://www.aulro.com/afvb/images/imported/2009/07/1020.jpg

Then i trial fitted the Disco booster....
Sweet as..

You will notice in the next pic the differances in the County and Disco booster.
https://www.aulro.com/afvb/images/imported/2009/07/1021.jpg

And the pedal to plunger is smaller on the County, so i drilled mine out to about 11mm, that is the size the County one was/is
https://www.aulro.com/afvb/images/imported/2009/07/1022.jpg

Then a Trial fit again
https://www.aulro.com/afvb/images/imported/2009/07/1023.jpg

Then i bolted it all up and popped it in the county.
https://www.aulro.com/afvb/images/imported/2009/07/1024.jpg

Now this is where you will get caught out...
The county master cylinder has 2 different thread sizes. The rear pipe is the same as the Disco, but the front is not... so i ratted the short solid pipe of the rear diff on the donor disco and it was perfect... with some bends....
Ohh and the Vacuum hose will need to be lengthened.

Then i blead the system and took it for a fang....

Yeps its stops..... and locks at 100kmh... time for new disc's and pads and i'll be happy...

Clarkie

[abaddonxi]

Brake fluid reservoir looks a little unlevel?

[sclarke]

Brake fluid reservoir looks a little unlevel?

Yeps.... it does look unlevel as it is not the correct one for the county or fender.

BUT the master cylinder is the same angle as the original and its only the reservoir that is on an angle. The disco booster in the disco lays back a bit. If i was really enthusiastic, id find a reservoir that is the same spacing and on a horizontal plane and then fit it..

Bonus with the disco one....
You can run the sensor in the cap to tell you if your low on fluid....
That is very handy on steep inclines and declines....

Ohh and the Disco one holds more fluid than the County one....

[justinc]

Thanks Clarkie,

As I said I never have time for any of this, you've done well and good pics too!

JC

[defmec]

thanks for the info champ as im just about to fit my disc sals on my 85 county you have saved me hours of swearing and frustration :BigThumb:

[dobbo]

Wonderful

So what other problems am I going to get?

I was told it was a case of bolting up adaptor plates and County hubs to the rear end, is this not the case?

[sclarke]

Wonderful

So what other problems am I going to get?

I was told it was a case of bolting up adaptor plates and County hubs to the rear end, is this not the case?

Cant answer that as my rear end is from a 98 130, it was factory Disc rear.
I have the plates New, but never used them...

[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?

[cal415]

Did either of you make any changes to the proportioning valve?

[defmec]

Did either of you make any changes to the proportioning valve?
no i just bolted the rear on and used stainless brake lines

[clean32]

Wonderful

So what other problems am I going to get?

I was told it was a case of bolting up adaptor plates and County hubs to the rear end, is this not the case?
dint do it, there really is no advantage to it as far as i can see. if you spend a bit of time off road the rear disks and pads cut out quite quickly etc. the only real problems with rear drums is if some one gets the drum and pad sizes mixed up which i suspect happens more often than not.

[sclarke]

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...

[steveG]

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 :angel:)...
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 :D
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

[loanrangie]

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

[steveG]

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

[sclarke]

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

Das auto is good. I has many vw's now. Sad isn't it.

Amarok has 120k on it now.
Vw Syncro is good. But not a 110 in no way