Thread: Brake Fluid Reservoir Placement

Hello All,

Being new to the arrangement of brakes and not having pulled a brake drum off a six cylinder equipped Series 3 before - can anyone tell whether the arrangement of my 2.25 litre diesel is still running the original four cylinder brake arrangement? Or has a previous owner been nice to me and perhaps upgraded it to a six cylinder arrangement - while still keeping the single circuit system?


The vehicle - Baldrick had a home-built camper on its back that weighed a tonne so maybe the previous owner upgraded the anchors?

Well I can live in hope can't I?

Kind Regards
Lionel

Originally Posted by Lionelgee

Hello All,

Is there any requirement to have the outlet of a brake fluid reservoir above or close to the inlet of the brake master cylinder in height?

My 1976 diesel came with a brake fluid reservoir that mounts remotely to the clutch pedal box (Part Number 90577636). It is a single circuit brake system.

When I did a test pressurisation of the reservoir I found a crack in the side of it and that is where my brake fluid had been leaking out of.

I have a spare reservoir however instead of the outlet coming off the side of the container like the original part did the fluid exits out the bottom through a long alloy threaded junction. To be able to link the connecting pipe from the bottom of the reservoir to the inlet of the brake master cylinder I will have to have a "s" bend made that is pretty deeply curved.

Will this change in the distance and height the fluid has to travel affect the operation of the brakes?

I was quoted $350 for a replacement reservoir that has an original side exit point for the brake fluid

So would the lowering of the exit for the fluid and having a deep "s" - bend affect the ability for the brakes to work properly?

Kind Regards
Lionel

The reservoir has to be above the M/C, length of pipe and its bends does not matter, except you need to be aware that too sinuous a route could cause bleeding problems - air may get trapped in any peaks in the pipe, and not purged when filling if there is not enough height. Any high points in the pipe must not come above the base of the reservoir.

John

Originally Posted by Lionelgee

Hello All,

Being new to the arrangement of brakes and not having pulled a brake drum off a six cylinder equipped Series 3 before - can anyone tell whether the arrangement of my 2.25 litre diesel is still running the original four cylinder brake arrangement? Or has a previous owner been nice to me and perhaps upgraded it to a six cylinder arrangement - while still keeping the single circuit system?


The vehicle - Baldrick had a home-built camper on its back that weighed a tonne so maybe the previous owner upgraded the anchors?

Well I can live in hope can't I?

Kind Regards
Lionel

As far as I can tell without a clear view of the drum, that is the "six cylinder" brake. (the four cylinder brakes have a sloping surface between the wheel mounting surface and the cylindrical bit, same front and rear, the six cylinder do not) These were fitted to all 109s from about 1980 at least in Australia, but by then certainly all the Australian ones had dual circuit brakes. Which is non-original will depend on the date of the chassis. Although it is always possible that the vehicle was sold new in a jurisdiction where the single circuit brakes were retained.

John

Lionel,

Checked the UK suppliers and the plastic master cylinder is between 100 & 113 GBP but is 'genuine' LR.
A metal replacement is cheaper ? 90/577636 REP - Brake Fluid Reservoir, Series 3 and 101 Forward Control, Metal

Does your vehicle have a servo ?

My SIII 88" has been fitted with LWB brakes and servo so should stop well once I get it roadworthy, plus it's dual circuit.





Colin

Originally Posted by JDNSW

The reservoir has to be above the M/C, length of pipe and its bends does not matter, except you need to be aware that too sinuous a route could cause bleeding problems - air may get trapped in any peaks in the pipe, and not purged when filling if there is not enough height. Any high points in the pipe must not come above the base of the reservoir.

John

Hello John,

Thank you for that information. Hopefully my pressure bleeder will minimise any bleeding problems. Another option may be to mount the reservoir on a bracket fixed to the fire wall somewhere. I have to make a special length of pipe anyway.

Kind Regards
Lionel

G'day Colin,

The diesel is a single circuit non booster - non servo brake system. I checked the UK availability of parts - so double the UK pound amount plus add about 30 pounds for the freight and it comes in close to the Australia suppliers price.

I have attached a parts drawing of the type of reservoir - genuine part.

Kind Regards
Lionel

Originally Posted by Lionelgee

G'day Colin,

The diesel is a single circuit non booster - non servo brake system. I checked the UK availability of parts - so double the UK pound amount plus add about 30 pounds for the freight and it comes in close to the Australia suppliers price.

I have attached a parts drawing of the type of reservoir - genuine part.

Kind Regards
Lionel

Lionel,
The metal reservoir replaces the original and is not affected by sunlight like the plastic version.
At about $115 plus freight it would be a cheaper & longer term solution.

My 88" should be a non-boosted circuit. Fitting the SIII servo assisted booster would be an option to improve the braking but you might have to change the alternator to one with a vacuum pump. My Isuzu 2.4 has a vacuum pump so the booster isn't a problem.

Colin

Originally Posted by gromit

Lionel,
The metal reservoir replaces the original and is not affected by sunlight like the plastic version.
At about $115 plus freight it would be a cheaper & longer term solution.

My 88" should be a non-boosted circuit. Fitting the SIII servo assisted booster would be an option to improve the braking but you might have to change the alternator to one with a vacuum pump. My Isuzu 2.4 has a vacuum pump so the booster isn't a problem.

Colin

G'day Colin,

Yes the vacuum pump was one of the reasons why I thought I would stick with the non-boosted single circuit system until the vehicle is on the road and registered. I will go the dual circuit boosted system after the brake system starts to need a major overhaul. My first priority is to do as much as needed to get the thing registered. Mechanical updates and improvements such as dual circuit boosted systems can keep for later.

I will look at utilising what I have now and at the possibility of finding a different remote place to mount the reservoir. At the moment there are clearance issues with the steering mechanism. This is because of the non-genuine reservoir having its exit point come out the dead centre of the bottom, instead of a side exit.

Kind Regards
Lionel