Thread: Brake Fluid Reservoir Placement

Originally Posted by JDNSW

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

Hello John,

Apart from the brakes it is a stock standard 1976 2.25 litre diesel. Oh and all forms of electrical wiring circuits that could be installed by a former long term owner, who was an electrical engineer.

Circuits that were unfortunately hacked up by the owner immediately before me who did not know sh-t from clay and just ripped stuff out.

I found numerous permanently live wires touching at various points on the chassis even with the ignition turned off

Maybe the previous owner, two ago, the electrical engineer had enough foresight to upgrade the brake cylinders and backing plates to give the camper better anchors.

Hmmm how can I tell the difference between six cylinder front backing plates and 4 cylinder front backing plates?

If it is the case then happy me

Kind Regards
Lionel

Originally Posted by chazza

I bought the plastic version from Craddock last week and unlike the original the outlet pipe drops vertically from the base and is not a side-exit!

I will have to see if it fits, but it isn't looking too promising

Wish I had known about the steel version,

Cheers Charlie

Charlie,
The correct plastic version was available from Paddocks (100GBP) & LR Series (113 GBP). In both cases listed as genuine.

Colin

Originally Posted by Lionelgee

Hello John,

.....

Hmmm how can I tell the difference between six cylinder front backing plates and 4 cylinder front backing plates?

If it is the case then happy me

Kind Regards
Lionel

If the shoes are the same width front and back - you have four cylinder brakes; if the front shoes are wider, you have six cylinder brakes. The backing plates will only fit the appropriate shoes - the centreline of the shoes is the same, so the backing plates for the wider shoes have to be dished to fit.

John

Lionel,

Hello again from Brisbane.

As John stated previously, apart from simply putting a tape measure across the lining (3" = 6 cylinder) the drum shape is different for the 6 cylinder 11" X 3" brakes - has a squarer profile than the 4 cylinder arrangement and/or the rears which have a tapered edge.

The backing plates are slightly more offset (dished inwards) to accommodate the extra 0.5" width while keeping the original centre line (that's also why the drum has the squarer profile - both sides are 0.25" deeper for the wider lining). Everything else except the drum, plate and lining is the same.

If it turns out that you don't have the 6 cylinder drums on your truck I have a spare set of backing plates here in Brisbane and also (likely) drums.

Cheers,

Originally Posted by gromit

Charlie,
The correct plastic version was available from Paddocks (100GBP) & LR Series (113 GBP). In both cases listed as genuine.

Colin

The word "genuine" doesn't appear on their current listing, nor in the fine-print in their terms-of-sale at Craddock. The one I purchased would fit a 101, but I will report back on its suitability for a S3,

Cheers Charlie

Hello S3Ute, John, Gromit and Chazza

I strolled into my shed armed with a tape measure this morning.

I measured the width of my front brake shoes - 76 mm or 3 inches


Thanks for the offer of the backing plates S3Ute ... I am set pretty right for parts as I bought an ex-military S3 without an engine from a scrap metal yard for a very good price. The bonus was that it still had some choice goodies left on it. Nice little things too like a full set of tool holders, a complete hand throttle and six cylinder brakes.

The down side was it has a non functioning brake system, a very unserviceable brake master cylinder, a shattered reservoir and hacked up brake lines. All the brake components on each corner of the wreck are still there for spares.

Kind Regards
Lionel

Hello All,

I went to the local hydraulic pipe and coupling place where I had dropped off a couple of pieces of fencing wire that I had bent into the shape of the brake and clutch lines that I needed. Unfortunately they had thrown out the new parts along with my old fittings the week before.

Back to square one and having to take different sections of pipe so I could get male and female threads to match - since their other halves no longer exist.

However, I am concerned about the non-genuine remote brake reservoir and how it has the brake fluid exiting underneath the cylinder and not through the side like the genuine reservoir does. It seems to me that due to the low release point of the non-genuine reservoir the brake fluid will have to defy gravity to reach the inlet mounted on top of the brake pedal box!

The reason is the genuine part side-feed reservoir has the fluid constantly above the inlet mounted at the top of the brake pedal box. It looks to me like the non-genuine reservoir with its long threaded adaptor that releases the brake fluid at the bottom of the cylinder will not be able to gravity feed the fluid all the way back up to the top of the brake pedal box inlet.

The only way to get the fluid from the access point at the bottom of the non-genuine reservoir cylinder is to screw the pipe to the bottom of the reservoir then bend the pipe up. The pipe then goes across the width of the steering box and then bends again and travel further up to join into the inlet at the top of the pedal box. So the direction of the pipe is to continue down further under the reservoir - dog leg across and then go higher than the point the fluid leaves the reservoir outlet to join up to the pipe screwed into the top of the pedal box.

As far as I know fluid unless pressurised does not gravity feed that far up beyond its release point.

Have a look at the attached photographs and see what you think about the ability of gravity to allow the brake fluid to travel from the reservoir to the brake inlet at the top of the pedal box?

The first photograph shows the position of the original part reservoir with the outlet on the side and the joint where a piece of rubber hose joins on to the inlet at the top of the brake pedal box.

The second photograph shows the original reservoir and the outlet at the side - bottom.

The third photograph shows the angles the fluid will have to negotiate under the pressure of gravity - or most likely not travel under the force of gravity .

The last photograph shows the fencing wire model that will be used as a template for a length of steel brake pipe. The photograph shows the path the pipe has to travel beneath the reservoir and then travel across the steering box and go up towards the brake inlet - going up with gravity

I am starting to think it might be best to give the non-genuine reservoir a big miss. I have a booster and pedal box that I was going to convert to a dual circuit system.

I wonder if a temporary measure might be to fit the booster with a single circuit reservoir? Can the brakes work if the booster does not have a vacuum as it is a stock standard diesel with no butterfly valve, no pump working off the fan belts or a alternator with a vacuum pump fitted out of a Series 3 Isuzu diesel. Can the brakes work without the booster having a source of vacuum.

I do want to go the full route of fitting dual circuit lines after I can have a mechanic check over the diesel engine and give it a clean bill of health. Plus fix the smoking issue it has.

I want to be able to get an interim registration and drive it to the diesel mechanic's place. See how much work the engine needs and then get it registered - if the engine is okay.

Then when the brakes need more work to be done I will go the full hog of fitting dual circuit brake lines.

So do people think getting a new brake line made to from the non-genuine part reservoir can manage to defy gravity and feed the brake inlet?

Or should I change the brake pedal box off, fit a brake booster and a single circuit master cylinder with the matching reservoir that is in a position that it is meant to operate from originally? Will this brake system work without the vacuum line going to the booster?

I want to be able to use what I have in the shed without having to outlay money because I am now officially in-between jobs and a new work contract seems a long way off at the moment.

Kind Regards
Lionel

G'day Lionel,

In my very humble and uneducated opinion, I would think that so long as you can bleed the system, you shouldn't have a problem.

The upper level of fluid in the reservoir will be above the inlet point on the pedal tower so I think you will get a siphon effect from the fluid as it feeds through the system.

Regards,

Marty.