109 brake conversion on an 88

[msggunny]

I remember reading that you can swap 11in brakes up front on an 88 to make it stop a bit better.

Anyone know were to find info on this?

Looking to start buying parts for it.

Thanks.

[jac04]

My Lightweight has the "big brakes" since it was built after July 1980, so I am very familiar with this set-up (having replaced every part of the brake system with the exception of the backing plates).

In July 1980, Land Rover changed the 88" brakes to 11" in front (same as the 109" brakes). However, at the same time they changed the rear brakes to make them the same as the 88" front brakes used up to June 1980. This was done to help maintain the front/rear brake bias. This means that your rear brakes should also be changed to utilize the larger 243296/243297 wheel cylinders (everything else in the rear will stay the same). The master cylinder changed as well to NRC6096.

Now, keep in mind that there was also a change to metric brake lines in July1980, so the NRC6096 master cylinder has metric threads. If you use this MC you will need to change the fittings on the ends of your current lines. The threads on the wheel cylinders never changed to metric, so you will use the common 88" SIII front flex lines, brackets & short hard line to wheel cylinders.

For the 11" front brakes:
Backing plates = 246566/246565
Brake adjuster kit axle set (if req'd) = RTC3176
Steady posts = 607808 (qty 4)
Wheel cylinders = 243744 (qty 2) and 243743 (qty 2)
Wheel cylinder o-rings = 505790 (qty 4)
Hard line from upper to lower wheel cylinder = NRC5347 (qty 2)
Hard line from flex line to upper wheel cylinder = 537763 (qty 2)
Flex line = RTC5903 (qty 2)
Flex line bracket to swivel housing = 577697 (qty = 2)
Shoes = RTC3417 (axle set)
Springs for shoes = 234889 (qty 4)
Drums = 576973 (qty 2)

If you do this conversion, make sure to bleed the brakes BEFORE mounting the backing plate to the swivel housing. This will allow you to lay the brake ass'y horizontal with the bleed screw facing up. this makes getting all the air out easy.

I hope this info helps.

[msggunny]

WOW! thanks man, thats a lot of info. Well done!

I am going to have a bit of work ahead of me but seeing as i am going to change out the chassis soon i might as well do it all at the same time. Along with stuffing in the Salisbury.

Thanks!

[jac04]

Glad I could help out.
If you are going to buy the parts new, I suggest contacting PA Blanchard for things like the backing plates and steady posts. The steady posts are very hard to find and PAB has them (that's where I got mine), and the backing plates are reasonably priced.

[yorker]

90577520 (90577520, BRAKE MASTER CYLINDER LWB upto 1980) should work rather than NRC6096. That should keep it all pre metrickery.


or you can do the Ford MC swap:

In a message dated 4/4/2005 Nosmoke wrote:

I started out this mission because my brakes were just
plain old rotten. I had to double pump the pedal to get
good stopping power and then at best the brakes were just
ok. I was never able to get my brake pedal to be hard and
provide much stopping power no matter how much I bled them.
The first clue to this problem came up a few weekends ago
during a routine oil change I noticed that my MC was all
gooey. As I laid under the Rover looking up at this I got a
big drop of brake fluid in my eye….ha! The MC was leaking.
As the days went on the leaking got worse. So much so that
there were puddles on the ground underneath the MC location
and I had to put a pint of fluid in the reservoir a day.

I ordered a MC rebuild kit from George at RDS with
intentions of rebuilding the original when I saw on the G&R
board a domestic MC that would fit the original servo unit.
I was much more interested in going this rout than
rebuilding the original or dropping $230 for a new
original.

I installed the 1985 Crown Victoria MC this weekend.
It works great. Here is what you need to do the conversion:

MC: NAPA #.4739467
One 5/16 male to 3/16 female adaptor
One Male to 3/16 adaptor
Two 3/16 SAE threaded lines
Flaring tool
One 3/8 X ? Bolt with the head cut off to 1 5/16. You
will want to use a bolt similar to the bolt that holds the
door hinges onto the bulk head because you need the tip to
be tapered to fit snuggly

Step one:
Detach existing brake lines going to MC. With a pipe cutter
remove the original fittings and replace with SAE fitting
from the above mentioned SAE lines. Flare with a flaring
tool.

Step two:
Remove old MC and place on book shelf as sculpture art or
save for your original restoration job.

Step three:
Plug lines of new MC with threaded caps and bench bleed MC.
Fill with brake fluid and pump with provided shaft until
only 1/8 of movement is allowed.

Step four:
Drop above mentioned 3/8 bolt with removed head into the
shaft of the new MC. The reason that you have to do this is
because your new NAPA MC has a hollow push rod, The
original is solid so that space needs to be made up to
accommodate the length of the existing push rid on the
brake servo…..hard to explain….but easy to see once all the
parts are in front of you.

Step five:
Install MC onto existing servo unit. There should be about
of space between the servo unit and the new MC where the
servo push rod is connecting with the 3/8 cut of bolt.
This amount of pre-hydraulic is necessary to obtain the
correct travel of the MC push rod. Bolt MC down to servo.

Step Six:
Connect SAE threads onto new MC

Step seven:
Bleed system; see technical manual for ok instruction, but
read the following on the correct way to bleed 109 brakes.
My Wife and I have tried several different methods of
bleeding the notorious 109 brakes with no success. The
following is the ONLY way that we have found works and if
you would try the brakes in our 109 you would think twice
about needing disk brakes….unless your running a V8.
Obviosly someone needs to be pumping the brakes inbetween
all of the steps:

1. Left rear Bleeder
2. Right rear Bleeder
3. Front left Bleeder
4. Front right Bleeder
5. Left front TOP brake line fitting
6. Left Front Bleeder
7. Right Front TOP brake line fitting
8. Right Front Bleeder

The reason for the extra steps 5,6,7 and 8 are because air
travels to the top of fluids. For whatever reasons LR put
the bleeder on the bottom cylinder. You will be shocked and
surprised when you have your partner pump the brakes up
solid after completing 1,2,3 and 4 and you then crack one
of the front TOP brake fittings and the pressure is so
great that it steams out in a mist!! Thats why so many
folks with 109s are driving around with mushy brakes. Also
note that steps 1,2,3 and 4 are pretty easy to bleed as are
7 and 8. Steps 5 &6 can take a few times to get all the air
out. My wife will attest to that as I am sure her legs are
sore right now. I believe that it took 4 times step 5 and 3
times step 6 to get all the air out.

The conclusion:

Tons of braking power. The MC woks way better than any LR
MC that I have ever had but I have never had a new LR MC so
maybe they are just as good and they BETTER be for $230
when the NAPA one costs $37. Needless to say its nice to
finally have good brakes……now that I can stop I just need
to get that new engine in so I can start up a little quicker!!

[yorker]

http://gunsandrovers.yuku.com/topic/5146

[yorker]

http://forum.landrovernet.com/showth...aster-cylinder According to CCKW353a1 569671 works fine with LWB brakes.

[yorker]

see also: http://www.lrfaq.org/Series/Hydrauli...iesMaster.html

[greenmeanie]

There is also a pretty simple trick to add a line to the front brakes that allows you to move the bleed nipple up to the top cylinder. It makes bleeding the big brake Rovers simple with no messing about with removing back plates or cracking joints.