86" brake upgrade options

[Warb]

When I upgraded the brakes on my S2 SWB I simply used a dual circuit servo pedal assembly with the larger diameter twin leading shoe backplates etc. However the outrigger mounted master cylinder on the 86" does not look like this path is viable. It does look like I can get an inline servo squeezed in to the area under the air filter, but that reduces pedal effort rather than increasing braking efficiency.

I'm not really interested in going to the effort and expense of a disc conversion, but I'd like more braking than the 10" single leading shoes provide. I can probably gain a bit with new drums and Mintex (soft) shoes, but are there any other options?

Before I undertake too much research, I thought I'd ask if there is an accepted approach to upgrading S1 (86") brakes? A search indicates I can fit a S2 master cylinder, but that doesn't seem to be an upgrade (more a use of available parts) as the braking system remains 10" 1LS.

I'm assuming that the S1 master cylinder is the wrong bore to properly activate 2LS wheel cylinders, so what options if any exist?

[mick88]

I have VH44 in line booster in the right hand guard area of my SWB series 3 and it fits neatly.


Cheers, Mick.

[Lotz-A-Landies]

Hi Warb

In-line and pedal mounted boosters only reduce the effort your boot needs to apply a certain pressure to the hydraulics.

I know of one person who fitted the pedal boxes from an SIII onto an S1 88", but can not remember if he used pedal mounted booster type. That would be your easiest option if you want to go to dual circuit and larger 11" brakes. You would however have to modify your Rt inner mudguard.

I do know people have fitted SII/SIIa master cylinders with the two bolt flange onto the outriggers and you may well find a dual circuit cylinder to do the same.

In relation to in-line boosters, the recommendation is that they should not be mounted higher than the master cylinder to prevent air locks by bubbles rising to the highest point. This can partially be solved by using a booster that has a bleed nipple. It was common for the in-line booster to be mounted behind the gearbox.
I have VH44 in line booster in the right hand guard area of my SWB series 3 and it fits neatly.

Cheers, Mick.Hi Mick

That's a great place in the SIII and even the SII/SIIa however that area is different in the S1 and a little more difficult, also see my comment about the height of the booster in relation to master cylinders on the chassis under the floor in S1.

[Warb]

In-line and pedal mounted boosters only reduce the effort your boot needs to apply a certain pressure to the hydraulics....

In relation to in-line boosters, the recommendation is that they should not be mounted higher than the master cylinder to prevent air locks by bubbles rising to the highest point.

Both very true!

With regard to the pedal box, I have never inspected an 88" S1 but from your comment I assume it also has the under-floor master cylinder. So if the firewall is more or less the same, then if the pedal-box style brakes can be made to fit the 88" the same should apply to the 86".....? My concern would be whether the firewall, which was never intended to have such a pedal box mounted on it, might be less strong than the S2 version in that area? I shall have to do some investigating!

I'll also have to have a quick check to see if the dual circuit master cylinder might fit under the floor, and whether a remote reservoir could be fitted!

Edit:

I forgot to say that when I discussed the positioning of the servo with Terry at Hydroboost, he mentioned a couple of things. Firstly was that having the servo higher than the master cylinder could cause the first push of the pedal to be "long", which I assumed was the same issue as mentioned by Lotz-A-Landies above. Secondly was the requirement to fit a remote breather, sealed to the servo air inlet, if the servo is in a low or exposed position. The breather is sealed to the servo with mastic, and the attached hose is routed up to "clean" air higher in the engine bay.

[Lotz-A-Landies]

Hi Warb

Some reinforcing of the footwell in the S1 would be required, but even in the S2/S3 the reinforcing is merely another piece of sheet metal about 2mm applied to the top.

You could probably salvage the part off a later dead firewall or cut one out of sheet and weld or glue on onto your S1 footwell.

Some boosters are made for an extended breather, the Clayton Dewandre used OEM on UK built SIIa and SIIb forward controls, and the VH44 has similar.

https://www.aulro.com/afvb/images/imported/2015/09/82.jpg

It was basically a thin disk with a pipe and hose. The disk fitted underneath the standard dust filter spring clip and the hose finished up on the firewall by the steering column.

[Warb]

The VH44 is the unit that Hydroboost recommend, and the one that I am familiar with as it is the one used for Mini's.

However I am now wondering whether the S2 style pedal box is a better option, as I have all the parts to hand and making up suitable reinforcement for the firewall is easy enough. It would also allow me to upgrade to a complete LWB brake system with servo and dual circuits etc. My only slight reservation is that this is such an original vehicle (if we ignore the Holden motor currently fitted!) that "cutting" seems sacrilegious, but on the other hand it's only an 86" and not really that rare. If upgrading the brakes allows it to continue to be used safely on modern roads, that can't be bad..?

Tomorrow I shall have a serious measure up and see what a pedal box installation involves!

[crackers]

Are you building a museum piece or a vehicle you want to drive?
I wouldn't sweat on the modifications. I say this because you obviously want better brakes so fit them and feel comfortable. To satisfy the quest for originality at a later date, make sure that anything you do can be reversed.

[gromit]

Less 86" made than 80".

Land Rover FAQ - History, Production, Sales - Production Data (http://www.lrfaq.org/FAQ.3.LR_production.html)

I'm running a Series I on the original braking system and it does take some 'forward planning'.
Personally I'd try not to make any non-reversible changes but I understand why you might want better brakes.

You suggested new drums & softer linings, why not see whether these make a big difference before cutting anything. If you do upgrade further at least you'll know the drums & shoes are as good as you'll get.


Colin

[Warb]

Are you building a museum piece or a vehicle you want to drive?
I wouldn't sweat on the modifications. I say this because you obviously want better brakes so fit them and feel comfortable. To satisfy the quest for originality at a later date, make sure that anything you do can be reversed.

Normally it wouldn't worry me in the slightest, but then normally by the time I've steam cleaned a vehicle I've found several holes in the chassis and I'm already resigned to doing some welding. This vehicle has a perfect chassis and only one tiny hole in the firewall (now fixed). It has been stored in a shed, been used/loved for most of its life by 3 generations of one family and could be rego'd in QLD with zero work. That's the only reason for the slight hesitation! But I'm over that now, and tomorrow I'll be measuring it up for improvements! If I can get a dual circuit servo'd pedal box to fit, that's what it will have!

[Warb]

Less 86" made than 80".

You suggested new drums & softer linings, why not see whether these make a big difference before cutting anything. If you do upgrade further at least you'll know the drums & shoes are as good as you'll get.

I seem to remember there were only about 1500 RHD CKD S1's made in 1956, but my collection of random LR remains from local farms means I have 3 86" but only 1 80" (and one tray back LWB S1). So 80" seems rarer to me!

The problem with replacing the existing drums and shoes is that if I can get the later pedal box to fit, then it would seem sensible to also include the bigger drums and 2LS front brakes (I believe this was the very late S3 SWB configuration, though I could be wrong!), which nullifies any money spent on 10" parts. Otherwise I agree it would be a good plan!

[Lotz-A-Landies]

The 11" x 3" wide front drums came out on the SIIA forward control in 1962, they were fitted to the S2A six cylinder in 1967 the booster pedal box came out on the six cylinder in 1969 IIRC and continued on all SIII six cylinder and by late SIII all had the booster pedal even if they were 88" or 109" (around 1980).

So there are plenty of donor models (including Army SIII) to donor the pedal box off.

[Warb]

My army SIII would be very upset if I swiped its pedal box, but I do have a couple of 6 cylinder S2a's that would complain less.... they might also be persuaded to offer up their back plates etc. to the cause!

[Lotz-A-Landies]

More importantly the SIIa will have the correct size wheel studs, not that you'd be using old drums.

[Yorkshire_Jon]

I'm watching this with interest... I got my 86" firewall reinforced (2mm sheet) and fitted the pedal boxes. I also got the 11x3 drums on the front before work dragged me away from home for the best part of 18 months...

Back at home now and itching to get the car rebuilt.

From memory the inner wing needs some butchering to accommodate the pedal boxes but I'm interested to hear what's the best solution with regards servo assisted brakes. Also, do the tears remain the standard 10"?? I'd hoped to leave the rear axle alone... At least for now until I get around to the Diffs:)

[Warb]

From memory the inner wing needs some butchering to accommodate the pedal boxes but I'm interested to hear what's the best solution with regards servo assisted brakes. Also, do the tears remain the standard 10"?? I'd hoped to leave the rear axle alone... At least for now until I get around to the Diffs:)

I've been distracted with another LR and some health issues, but whilst investigating the "vague" steering in my '56 I noticed that another of my 86" LR's has a later type steering box fitted. This in turn lead me to consider whether the better option is to address the pedal box and steering fixes/upgrades together, rather than potentially making two separate assaults on the firewall....

My (non LR) experience of braking systems is that because of weight transfer the rear brakes are far less important than the front under heavy braking. Having said that, how often will the front brakes of a LR cause the rear wheels to "un-weight"? Any time the rear wheels have weight on them they have traction and therefore can assist with braking. Too much braking for the available traction and the wheels will lock. In racing cars we used to use an adjusting valve that allowed us to increase/decrease the amount of rear braking to suit the conditions. In an old LR I don't think you'd want the rears locking up prematurely......

The rear brakes also serve the function of providing drag at the back to prevent the rear of the car acting as a large pendulum and overtaking the front (spinning) when braking through a corner. The tendency to spin with little warning usually worsens with decreasing wheelbase, so the 86" with improved front brakes might well behave this way. This happens when there is too little braking at the rear, but "too little braking" refers to the force applied to the ground, rather than the "brakes" themselves. So "too little braking" also happens when overly large brakes cause the rear wheels to lock, because a skidding wheel provides less deceleration than a braking+rolling one (static friction is greater than kinetic friction).

My thought would be to improve the rear brakes, but if you want to do that at a later time then at least make sure that what you have now are working 100% (Mintex shoes, skimmed/replaced drums etc.). If/when you do improve them, I'd stick with a combination that has been used (preferably in an 88") by LR themselves including the correct front/rear bias valves or dual circuit master cylinder etc., as this should result in a system with the correct front/rear balance. Failing that just make certain the rear brakes don't lock up early under any circumstances (damp road+heavy braking+cornering!).

That's my plan anyway!

[crackers]

I know stuff all about these old girls and driving them Warb, so treat this with that in mind:
I do wonder if you're over thinking this. I'd have thought that tyres were more important in controlling the vehicle than brakes, particularly considering the modest performance of these beasts. I'd also price/consider fitting a complete system from a later LR rather than mix and match on the grounds that some faceless engineer has earned himself a comfortable income doing the sums already.

Whatever, I completely agree with having the best components and having the whole system in the best condition you can get. Good brake drums and very good (and fresh) shoes will probably achieve more than anything else.

[Warb]

I'd have thought that tyres were more important in controlling the vehicle than brakes, particularly considering the modest performance of these beasts. I'd also price/consider fitting a complete system from a later LR rather than mix and match on the grounds that some faceless engineer has earned himself a comfortable income doing the sums already.

Fitting a system that was used by LR themselves is certainly the easiest way to get a good front/rear balance (I actually said it at the end of my last post!). However the 88" never had the 3" wide drums that Yorkshire_Jon has fitted, so that makes it harder!

Tyres are indeed very important, but if the pedal effort required to get the front brakes to "work" causes either too much or significantly too little rear braking, then problems can arise. It is almost certainly the case that a good modern tyre will outperform the original brakes so you'll probably struggle to lock a wheel under braking. But if we start to improve the brakes, and make tyre's job harder by putting it on a wet road and adding some cornering forces, then who knows?

Unlike acceleration, the need for braking is ultimately "out of our control". By which I mean that I can drive carefully, accelerate gently, prepare in advance for every maneuver and be as aware as humanly possible of hazards, but still on occasion there will be a need to hit that brake pedal hard - and it is that "worst case scenario" that we should target.

I should note here that I live in an area where suicidal 'roos, wombats and deer are (from what I can see) employed by the local smash repair companies to bolster their businesses, so I am constantly faced with the reality that something might leap out from behind a tree at any second!