Thread: So, 101 drum brakes DO work!!

Originally Posted by garrycol

Of course it is the main reason the rear wheels are off the road. I have tested this myself with the proportioning valve out of the vehicle - when unloaded the rear brakes on a properly set up 101 do not work as the valve shuts off brake fluid to the rear so all braking effort is via the front wheels so the rears can lift. With load, the rear settles on the suspension and cracks open the valve allowing fluid to the raer and braking is more balanced.

As I said the 101 valve is closed in unloaded position where a Landcruiser valve which is very similar is slightly open in the unloaded position - I have modified a landcruiser valve and have it installed on the 101 activating levers so I have some rear brakes when unloaded.

Garr

Garry do you have a write up of the mods you did to the landcruiser valve? I recall reading in the past you had done this, I think it was from a 75 series ute. Was it difficult or pretty straight forward?

I any day would be happy to reverse a 101 down a steep hill, loaded or unloaded.
The vehicle has a very strong parking brake( if the linkage and cable is good nick).
The brakes do work backwards if in good nick.
I personally reverse down a hill in low range reverse using the motor and the 101s excellent low gearing.
The unloaded weight bias of a 101 is towards the front,
Stall recovery proceedure should be used and therefore braking in reverse should not be too much of a issuse as the brakes only assist in the proceedure.......remember the excellent parking brake.
The brakes on a 101 landrover are more than proven, as the drum size, the shoes, wheel cylinders are exactly the same as a long wheel base series three landrover.
I dont hear too many stories of correctly driven series three landrovers which are legal for 3/4 ton off road have too much drama.
Are the short wheel base series three brakes the same.?
the differences are.
101 has simular booster , but not the same , different master cylinder and the proporsioning valve fitted.
The 101 has a pressure switch designed to work a warning light on the dash board if one brake circult is not working.

The hard part of a 101 is going down hill unloaded, as the forward weight bias, forward control drivers position over the front wheels, short wheel base, lack of flex on the rear suspension, makes things interesting, especially if you tap the brakes.
Every different type of vehicle has strenghts and weakness and has to be driven according to the diffent vehicles needs.
Going down hill in my 101 the greatest weakness is the driver chickens out very quickly

One other thing I find interesting is in the 101 drivers hand book about towing .( the vehicle was designed from the outset to tow a light gun without brakes fitted...I think its weight is about 1.5 tonnes and the powered driven trailer would have been 500kg unloaded with a 1.5 ton payload in the trailer that was vacuum braked)
It states the vehicle must have 500kg in the rear cargo area between the rear axle and the tail gate if towing a trailer.
It states the ballast load must be placed near the tail gate as rearward as possible.
In practice, in service towing a gun the vehicle was always fully loaded (one tonne in british service and aussie 101s 1.5 tonnes)as the vehicle carried the gun crew, gun crews personal gear, cam nets,cam net poles on roof, ready to use ammo, gun entrenching gear, gun laying gear, first aid, water, and food.
they were so loaded in british army service that everyones personal gear and what ever else that could was hung out side the vehicle as room was so short.
That light weight gun towing design spec is also reason why the 101s on road gearing is so low as standard , it is a gun tractor and the designed convoy speed would have been 40 mph in 1970 when the vehicle was designed.

Originally Posted by 101 Ron

I any day would be happy to revrse a 101 down a steep hill, loaded or unloaded.
The vehicle has a very strong parking brake( if the linkage and cable is good nick).
The brakes do work backwards if in good nick.
I personally reverse down a hill in low range reverse using the motor and the 101s excellent low gearing.
The unload weight bias of a 101 is towards the front,
Stall recovery proceedure should be used and therefore braking in reverse should not be too much of a issuse as the brakes only assist in the proceedure.......remember the excellent parking brake.
The brakes on a 101 landrover are more than proven, as the drum size, the shoes, wheel cylinders are exactly the same as a long wheel base series three landrover.
I dont hear too many stories of correctly driven series three landrovers which are legal for 3/4 ton off road have too much drama.
Are the short wheel base series three brakes the same.?
the differences are.
101 has simular booster , but not the same , different master cylinder and the proporsioning valve fitted.
The 101 has a pressure switch designed to work a warning light on the dash board if one brake circult is not working.

The hard part of a 101 is going down hill unloaded, as the forward weight bias, forward control drivers position over the front wheels, short wheel base, lack of flex on the rear suspension, makes things interesting, especially if you tap the brakes.


Every different type of vehicle has strenghts and weakness and has to be driven according to the diffent vehicles needs.
Going down hill in my 101 the greatest weakness is the driver chickens out very quickly

This was one of the reasons the Volvo Forward Control was rejected for applications here - rear wheels four feet off the ground and only recovery was to go faster downhill and pray! These sort of vehicles really probably only need lower gearing, or tow a log (or maybe a longer wheelbase) for use in steep country.

Bob

The idea of the load proportioning valve is good - supposedly auto controls the rear braking effort in all conditions - when loaded increases brakes effectiveness and when stopping where there is weight transfer to the front rear barking effort is reduced stopping the rears locking and possibly loosing control. Unfortunately as set up on the 101 there needed to be a bit more braking in the unloaded state. The piston in the valve only has a very small stroke so it is effectively either on or off with little in between.

When I first worked on my 101 brakes I could not get fluid to the rear brakes because of the proportioning valve being closed. To bleed the brakes I forced the valve open so the fluid could go through it. Later it started leaking so I took it out and pulled it apart to find it was corroded and needed replacement. New from the UK was about $400 at the time so I looked for alternatives. There are manually operated valves you can get from speed shops quite cheaply but I understand these are illegal on a road going vehicle so I didn't go that route - but to me these would be perfect for the 101 as you can adjust them for the load state you are in.

I went to the local toyota dealer and climbed under a Landcruiser and noted their system is basically the same as the 101 except it is activated from the diff in a sideways direction where on the 101 it is fore and aft but the actual valve is about the same size. I went to a wrecker and bought a cruiser valve for about $45 and cut off all its levers etc I had to drill some new mounting holes in the 101 valve mount and did slight mods to the 101 lever so it moved the piston on the valve correctly and adjusted it so that the valve was slighly open on in the unloaded state - the brake pipes were of a different thread but was fixed with an adaptor.

I have never had an issue with 101 brakes except for differential braking caused by the need to constantly adjust them. Never had an issue reversing as the front brakes work equally as well in either direction - also never had the rears lock up and I do know they are working. When offroad whether going forward or back the rear suspension does move a little (noting the rear is 1.5t rated so it does not move much) so effectiveness of the rear brakes varies as the diff moves up and down.

Garry

Garry,

If I recall both you and Ron have Detroit lockers fitted to your rear diffs. You are very unlikely to have a brake lockup with the rear end as the braking is equalised by the locker (it's a mechanical pre-historic Anti-Lock Braking System in this situation).

One rear wheel locking up is the usual problem leading to loss of control at the rear, rather than both.

Bob

Tales in 101 folklore say the NATO jaw on the front was there so when the back end lifted too far under heavy braking whilst unladen the hitch would touch the ground and cause it to bounce back and settle on its wheels.

Apparently.

Rather than start a new thread, my question seems to fit in here.

Has anyone here done the Disco 1 booster conversion on their 101 - with drum brakes? If so, how does it go? My brakes work very well for what they are but just need a heavy boot to make them work fully.

I have no intention of fitting disks, but was wondering if this conversion would help how hard I have to push the pedal? Biggest reason for looking at this is my right knee which plays up from time to time and braking tends to be one of the actions that hurts it.

Cheers - Gav.