11in front brakes on late 2A swb - upgrade option when new?

[Mustlust]

Was the 11 inch drum brakes an optional h/d upgrade available on the 2A 88in swb???
I am thinking that I have seen this as an option somewhere, but can't be sure.
This is another certification issue, as the upgrade doesn't need certification by the engineer if it was an option when new.
I wonder if it was, where could I find an acceptable reference to show the engineer!?!?!?

[debruiser]

would anyone know the difference anyhow?

[Lotz-A-Landies]

The 11" brakes were never an option on the 88" but they were a common retrofit by civilian owners. Most sought after were the 3" wide 11" assemblies from the forward controls and later the 6 cylinder bonneted models (late SIIa and SIII). I even, know people who fitted front leading shoe 11" assemblies on the rear (opposite side) that way you always have 4 leading shoes in the direction of travel whether going forward or reverse.

[debruiser]

Didn't the early 80's swb's come with the bigger brake standard? maybe on the v8's?

[Lotz-A-Landies]

The guidelines for light vehicle modifications from NSW RMS appear to indicate that fitting 11" Land Rover brakes to a Land Rover originally fitted with 10" brakes would come under the category of not requiring certification. see: section 16 http://www.rms.nsw.gov.au/documents/roads/safety-rules/standards/vsi-06-light-vehicle-modifications.pdf. While the example is fitting disks to a LC Torana from a GTR Torana, the 11" are greater specification than the 10" brakes and therefore meet the criteria for self certifying.

While the information requires all components must be fitted, which would indicate that you also have to fit the 11" master cylinder, it becomes less clear if you wanted to use the dual circuit M/C and booster pedal box (section 17) although that pedal assembly was standard on the late SIII 88" around 1980.

[Lotz-A-Landies]

Didn't the early 80's swb's come with the bigger brake standard? maybe on the v8's?

The very late SIII 88" most certainly had the boosted pedal box but I'm not aware about the 11" brakes. The V8 stage 1 and Isuzu Stage 1 had the same brakes as the suffix G SIIa six cylinder and SIII six cylinder = 11" with 3" wide fronts and boosted pedal box (dual circuit from around 1977)

The issue of whether late SIII 88 brakes are applicable options for a SIIa 88 comes down to the definition of are the SIIa and SIII the same "series" in the mind of the RMS.

[AV8R]

A bit late maybe but just for your information.
11" twin leading shoe front brakes were fitted as standard from the factory on 1980 and newer 88" Land Rovers.
The 10% larger diameter helps some. The width of the shoes increasing from 1.5" to 2.25" helps quite a bit more. The extra leading shoe per drum helps a lot. All in all a worthwhile addition, especially with larger than standard tyres. The larger brakes were not fitted to the back axle as it cauld cause the back wheels to lock up under braking
Running these 11"ers on my '63, 88" since 1982 without problems. It is on 255/85R16's nowadays, used to be 900's.

[JDNSW]

I assume you refer to UK produced vehicles. Worth noting that this would not necessarily apply to Australian built vehicles. If it does apply to them it is likely to apply at a later date. By this date, 88" Landrovers were becoming relatively rare in new sales here, with most buyers getting the 109.

[harry]

ok, dumb question, but where are 10 inch and 11 inch drums measured at?
is it the outer diameter of the drum or the inner diameter where the brake shoes act?
I just eyeballed my s2a fronts and the front drums appear to be about 12 !/2 inch at the widest point of the inboard rim of the drum
(of course that is a rough measurement as the wheels are still on, so a bit difficult to measure accurately.

and re telling the rego man, why bother, it's got brakes, why offer up info to confuse him.

[JDNSW]

It is the diameter of the working surface - easy to measure with the drum off, more difficult installed, but with a little experience can be identified at a glance. Front 11" brakes have two wheel cylinders, 10" only one and are the same front and back.

John

[Lotz-A-Landies]

It is the diameter of the working surface - easy to measure with the drum off, more difficult installed, but with a little experience can be identified at a glance. Front 11" brakes have two wheel cylinders, 10" only one and are the same front and back.

John
Just to a point of clarity. 109 inch wheelbase Landies from the very last Series 1 had 11 inch brakes but shoes were 2 1/2 inches wide front and rear. When the 6 cylinder model was introduced in 1967, the front axle was fitted with the 3 inch wide brake shoe assemblies which first appeared on the forward control models. The V8 and Isuzu Stage 1 SIII were fitted with the 3 inch wide front brake assemblies

You can tell the difference between the 2 1/2inch assemblies and the 3 inch assemblies by looking at the drum, the narrower type tend to have a noticeable chamfer around the corner while the wider type have a square corner or slight radius at that location. Be aware that the backing plates are different between both wide and narrow types as the cylinders are centred even though they look similar at a superficial viewing.

BTW: on 10 inch brakes the front wheel cylinders have a larger bore than the rear cylinders although everything else is interchangeable. (Front to rear, same side. There is no adjuster on the trailing shoe of 10 inch brakes.)

[Mustlust]

[bigsad]
Story so far....

I have used the original 10 in drum set-up for the rear. New drums and all components.
i have used 11 in drums from a 109 S3 on the front, all new components and also fitted the matching master cylinder. No servo assist.

I have retained the single line setup, without proportioning valve.

When I jump on the anchors, the rear locks up. When tested it was way below the criteria to pass for a safety certificate.

I am am guessing the line pressure is less than required at the front drums.

Do do I need to convert the single line using a proportioning valve? Will this resolve my braking issues? If so, which proportioning valve?

[JDNSW]

I think the problem you have may be that the rear brakes are suited to the original master cylinder and the front brakes to the lwb master cylinder. It may be able to be corrected by using a smaller wheel cylinder at the back.

However, this is not to discount the possibility that there may be more mechanical type issues, such as the shoes not fitting the drums closely enough, or poor (too hard) lining material. Or possibly incorrect assembly of the wheel brakes. My 109 with 11" brakes all round has no issues meeting the requirements.

The rear brakes locking before the fronts were working adequately would result in insufficient deceleration.

[Mustlust]

Thanks John.
The 5 way brake line junction that distributes the fluid to the brakes has 1 receiving join, 3 feeding fluid to the brakes, and one join for the brake light. I have possibly connected the lines into the junction block out of original position. I was wondering if the hole leading to the break light switch may be a different diameter and therefore restricting flow to the front brakes.

[Mustlust]

Strike that last post.
brake light switch is in correct position. However, I do have input for master in incorrect position and one of the others in the wrong spot. I can't see how this could be a contributing factor.

[Mustlust]

I've read elsewhere that some with TLS 11inch front brakes (as I have) are best matched with 10 inch rear brakes with a 1 inch brake cylinder instead of a 1 1/4 inch cylinder. How is the smaller cylinder helping???

[Mustlust]

Does it make any difference which way the brake cylinder pistons are facing with the TLS setup?

[JDNSW]

The smaller cylinder reduces the brake effort for the same pedal pressure, stopping the rear wheels from locking before the front brakes are working properly.

I am not clear what you mean by which way the brake pistons are facing. I don't think you can assemble the pistons in the cylinders the wrong way, but if you mean "does it matter which way the entire wheel cylinder is facing, it most certainly does. The cylinder must be pushing at the end of the brake shoe which is leading with the wheel turning forward, so that the braking force is transferred to the fixed end of the shoe, and the drag on the shoe pulls the shoe into more forceful contact with the drum. If they are the wrong way round, achievable by swapping left and right, you have practically no front wheel braking going forward.

[Mustlust]

It seems as though I may have put the brake set, i.e., backing plate and all attachments on the wrong wheel.

Every pic that I have googled shows the top piston pushing in a clockwise direction, whereas mine are pushing the other way. It looks as though everything is put together correctly, that is springs, shoes etc., but I just have L and R incorrect.

Looks like a morning on the spanners tomorrow....

[JDNSW]

Yes, from the photo, that is the wrong way - and certainly explains the lack of braking!

[68s2alwb]

Interestingly I was saved from making this error as my new replacement cylinders are handily stamped "L" and "R".

[Lotz-A-Landies]

Yes, from the photo, that is the wrong way - and certainly explains the lack of braking!
They would however be great braking when going in reverse! [thumbsupbig]

[Mustlust]

Yes folks, I can confirm that I had great braking in reverse. [bigsmile]

[Mustlust]

On the TLS 11 in brakes, there are connecting lines running along the backing plate feeding fluid from the top brake cylinder to the bottom. Each cylinder has a one flat and one angled threaded female connection.
My question is: does it matter which one receives fluid and which sends it? Should the input be on the piston side? I've put the bleed nipple on the bottom angled connection as this permits unobstructed access. Just wondering if the brake line is connected to the correct thread on the top cylinder.

[gromit]

It doesn't matter which connection you use. On all of mine the pipe linking the wheel cylinders is on the straight port. The bleed nipple & flexible hose go to the angled connections.

I've made sure that the connecting pipe is behind the swivel hub to give it some protection but again no reason why it can't be in front.

https://www.aulro.com/afvb/images/imported/2018/01/365.jpg (https://flic.kr/p/DEnviF)DSCN4625 (https://flic.kr/p/DEnviF) by Colin Radley (https://www.flickr.com/photos/152321353@N07/), on Flickr https://www.aulro.com/afvb/images/imported/2018/01/366.jpg (https://flic.kr/p/DEnycr)DSCN4623 (https://flic.kr/p/DEnycr) by Colin Radley (https://www.flickr.com/photos/152321353@N07/), on Flickr Colin

[Mustlust]

Thanks, that’s what I thought, but worth asking for confirmation. I think I’ll run the lead line to the bottom cylinder and locate the bleed nipple to the top for convenience.

[Mustlust]

Just relocated bleed nipple to top. Hopefully this will make tomorrow mornings work a little easier.https://www.aulro.com/afvb/images/imported/2018/01/456.jpghttps://www.aulro.com/afvb/images/imported/2018/01/457.jpg