Thread: County rear disk brake conversion, pics & p/n's

My understanding is the Disco booster has a dual diaphragm (AFAIK), which in practice gives a much lighter pedal for a particular brake pressure compared to the standard County one. The input rod is also a perfect length for the County pedal box.
I don't know how that relates to actual line pressures, or how it fits with the 6x6 brake system - but can confirm that it works really well on a 110

Steve

Originally Posted by 123rover50

Got the first kit , thanks Murray.
Now I am confused about boosters.
Why do we change to the disco one?
Is there a difference in the line pressure?
Does anyone know what the line pressure of these boosters is?
Does the front and rear run the same pressure or is one greater?

On the 6x6 I have no room for the mastervac so am running a VH40 for the front discs and a VH44 on each back axle. I now know this is not enough as the 44 only puts out 900 odd psi and the 40 does 1400 psi or so.
I was wondering how this pressure compares with the original boosters.

Help appreciated.
Keith

I'm not familiar with the boosters you're running, so can't be of much help.
Just to back up what Steve said, the D1 booster seems to have a lot more vac assist making for a easier application. The brakes have a bit (lot) more 'bite' with less pressure on the pedal.

Cheers, Murray

Originally Posted by mark2

Regarding boosters and master cylinders, does anyone have an insight as to whether the PBR master/booster as fitted to 110 Perenties needs to be changed when doing a rear disc conversion on a Perentie? Did the army change these when doing the rear disc retrofit?

Sorry for late reply mark, I missed your post. No change in mc. The PBR one is the same on drum or disc models.

Originally Posted by Bearman

Sorry for late reply mark, I missed your post. No change in mc. The PBR one is the same on drum or disc models.

Is the PBR m/c an improvement on the civvy mc's?

Originally Posted by mark2

Is the PBR m/c an improvement on the civvy mc's?

I couldn't say whether it's an improvement or not, but just part of the Australian content requirement for the tender when they purchased the Perenties. Although they are easy to find as they were also on Fords and Commodores about the same vintage.

Two things, with the 3 individual in line units, you probably need a vacuum acumulator tank so you have more than a single brake application before you lose your vacuum assist.

With the weight of the 6x6 what about trying to find some of the VH90 for the rears and a VH91 for the front?

There's a D1 booster on Ebay if anyone is looking for one for their conversion.

Landrover Discovery 94 To 98 Brake Booster And Master

Cheers, Murray

I have fitted this conversion and using the county front hubs it reduced the track by 10mm per side, this is because of the difference between the face that the drive flange bolts to and the flange that the wheel bolts to.

As far as I can find out the perenti conversion uses a special hub (AYG7305) that measures 14.5 mm the same as the drum hub with the drum on.

Longer wheel studs and a 10mm spacer would return the track back to STD, for clearance between the tyre and the top spring mount.

I would like to hear what others have found.

Cheers Jim.