10" or 11"... baby!

[TeZZaP]

Bear with me...

My original SWB restoration project, which I have named 'Tate', has 10" brakes, the new 'donor' SWB (called 'The Captain') that I have recently picked up has 11" drums fitted... is it worth 'upgrading' the whole system to be 11"? Are 11" brakes that much better than the original 10"?

The catch...

There are, of course a few curve balls... 3 of the 11" drums look the same to me, but the 4th, although still an 11" drum looks different. Plus the shoes, which are at a brake specialists waiting to be picked up, looked to me (when I saw them last week) to be as skinny as the 10" shoes; I thought the 11" shoes where 'wider'...? From my side of the fence it would be a bit faffy to move to 11", but if there is a significant improvement over 10" I may consider it... what do you guys think?

[UncleHo]

G'day TeZZaP :(

The 11" drums are from the LWB vehicles, and are a VERY good upgrade from the old SWB 10" single leading shoe design and I would say that it would balmost be mandatory to upgrade to 11" for today's traffic conditions :( the 11" brakes came in 2 types, the 4 cylinder vehicles had 2 1/4 wide shoes and the 6 cylinder vehicles had 3" wide front shoes, right up including the Stage 1 V8's, the Series 2a-3 6 cylinder vehicles all had boosted brakes, with later Series 3' s having twin circut brakes :) to really bring up your brakes to todays quality I would suggest that you fit a booster, either by using a Series 3 brake pedal box with booster, and the top panel of a series 3 Right front guard (has the cutout for the booster) the 10" inch brakes were only marginal way back in the 70's in Australia:( and I drive an Unboosted Series 2a LWB and there have been times when I have been cut-off I have wished I had Boosted 3" fronts:( if the Front drum has a 90deg, outer corner it is a 3" front drum from a 6cylinder, if a 45deg outer corner it is 4 cylinder LWB(they are the same as the rears) :)

SWB's have 10" single leading shoe brakes,(1cylinder per wheel) and LWB's have twin leading shoe brakes on the front 2 w/cylinders per wheel)


cheers

[LandyAndy]

An extra inch in dia gives the brakes a larger operating circumference,with that and the twin pistons makes for a much better brake.If you can get the 3" wide drums for the front grab them,they are great.You need the matching 3" backing plates as they are different to 2 1/4"
Andrew

[isuzurover]

The above pretty much covers it - hower just make sure you fit a LWB master cylinder if you do the swap. They have a bigger bore.

Don't fit the larger MC with the 10" brakes though - all it will do is give you a heavier pedal.

I will say though - a SWB with 10" brakes (unboosted) requires a lot less pedal pressure to stoip than a LWB with 11" brakes (unboosted). When I got my IIA it had a SWB MC. The pedal was quite light, but if the adjustment wasn't 100% it went to the floor.

[JDNSW]

Seconding the posts from Andrew and Kevin.

The 11" brakes are a very worthwhile addition to the an 88. As well as increasing the area, the extra inch increases the leverage of the braking relative to the wheel. However, I feel that the major advantage is going from one leading and one trailing shoe to two leading shoes on the front. With this I would not feel that a booster was necessary for the 88. But you must make sure that if you are using 11" brakes that you use the lwb master cylinder, as you are now operating six wheel cylinders not four.

I doubt that the wider drums would be much advantage in an 88 with an original engine, unless you live in a very hilly area - remember that brake area only affects resistance to fade, not overall braking effectiveness.

John

[Aaron IIA]

The 11" x 2 1/4" brakes will be a good upgrade for a SWB. Remember that a brake booster does not improve braking performance, but means that you do not have to push as hard on the brake pedal.
Aaron.

[UncleHo]

G'day TeZZaP :)

Yes, you must use the 1 inch bore Master Cylinder in either the CV type or the CB type ( one with the big nut on the end) as the SWB 3 /4 inch master cylinder will make it dangerously under braked, I know of 3 fatals that were caused by the wrong master cylinder being fitted.

cheers

[Lotz-A-Landies]

Yeah but when you buy 11" brake shoes there is more friction material so they cost more! :D;):p

[UncleHo]

WHAT PRICE SAFETY :o

[TeZZaP]

Thanks for all your replies guys, I will upgrade to 11", all I need to do is organise a matching set of Drums/Shoes/backing plates to start with, which, in theory shouldn't be a problem because I have access to a friend who has a large pile of these items!

My first question is; are the drums the same for the 2 1/4" and the 3"?

[JDNSW]

T.....

My first question is; are the drums the same for the 2 1/4" and the 3"?

No. Same diameter (11"), and fitting on the hub is the same, but the 3" drums do not have the bevelled section between the flat outer face of the drum that the wheel mounts against and the cylindrical section.

John

[TeZZaP]

An extra inch in dia gives the brakes a larger operating circumference,with that and the twin pistons makes for a much better brake.If you can get the 3" wide drums for the front grab them,they are great.You need the matching 3" backing plates as they are different to 2 1/4"
Andrew

Do you (or anyone else) have a pic of what the 3" backing plate looks like?

[TeZZaP]

These are the 11" drums I have at present, the second one down is the odd one out, from what everyone here has said that would be a drum for 3" pads then?

[isuzurover]

None of them are 3" drums.

3" drums have absolutely no chamfer - like this:
http://shop.dingocroft.co.uk/acatalog/593874.jpg
(this is a 101 drum though).

As an aside - it is a good idea to drill the drain holes out slightly larger. Stops them blocking up with brake dust and mud.

The screws that hold the drums on are completely unnecessary.

[TeZZaP]

Do you have a pic of the backing plates for 3"? I have two different ones (different shape holes for the wheel cylinder)

[JDNSW]

I think they are two alternatives for the 2.25" brakes. The 3" ones will have a deeper relief pressed into them, as the wheel cylinder has still to be in the middle of the shoe sideways, so it has to be further from the flange where it mounts on the stub axle. Same as your picture of the drums shows two different versions of the 2.25" drums.

John

[TeZZaP]

Thanks for all your wise words guys. I know have a set of 11" drums that are all the same +backing plates that are the same (2 front ones and 2 rear ones).

I also have the pedal unit with the servo +brake master/reservoir.

Just need to source wheel cylinders; I have not checked whether they are worth getting rebuild kits for yet... but chances are I'll need new ones I guess!

[lro11]

I setup my series 2 SWB with 4cyl 11" on the front and 10" on the rear with no booster, I could rest my big toe on the pedal to stop and they worked great.

[UncleHo]

G'day TeZZap :)

You could go all new Genuine wheel cylinders, or get your/ or second hand ones Stainless Steel Sleeved by a specialist brake coy. as I did years ago, it saves the wheel cylinders pitting out from moisture :)

the original wheel cylinders on mine were cast iron and not alloy.

cheers

[Aaron IIA]

You can buy new slaves in both cast iron and aluminium. They are usually both the same price, and cheaper than getting the old ones stainless steel sleeved. I just repaired the brakes on my SI. They were all siezed. I freed them up, honed them smooth, and used the original seals which were still good. If your old ones are not heavily pitted, you could hone them (hones cost less than $10) and fit new seals. Try this first, as you have not lost any money.
Aaron.

[JDNSW]

You can buy new slaves in both cast iron and aluminium. They are usually both the same price, and cheaper than getting the old ones stainless steel sleeved. I just repaired the brakes on my SI. They were all siezed. I freed them up, honed them smooth, and used the original seals which were still good. If your old ones are not heavily pitted, you could hone them (hones cost less than $10) and fit new seals. Try this first, as you have not lost any money.
Aaron.

Cast iron cylinders can be usefully honed unless pitted, but most if not all alloy ones should not be, because they rely on a specially thick hard oxide layer to provide the working surface, and honing removes this hard layer, so you are working on the much softer aluminium metal.

This will have a much shorter life, not only because it is softer, but because the thick oxide layer provided protection against corrosion.

Stainless steel sleeves can be installed into either cast iron or alloy, although companies that do it may have preferences.

John

[LandyAndy]

Go new wheel cylinders,Repco are the go.They are very reasonably priced due to being a common fitment on other vehicles.
I havent got seperated backing plates to show the difference,basically there is a 1/4" extra off-set towards the vehicle on the 3" backing plates,the rest of the difference is taken up in the brake drum.
Andrew

[dandlandyman]

Don't forget that the backing plates, shoes and cylinders are "handed" (left and right). Also, the rear shoes are different, trailing and leading.

Dan.
69 2a 88" pet4, 74 3 109" pet4, 68 2b FC pet6.

[TeZZaP]

Don't forget that the backing plates, shoes and cylinders are "handed" (left and right). Also, the rear shoes are different, trailing and leading.

Dan.
69 2a 88" pet4, 74 3 109" pet4, 68 2b FC pet6.

Considering all the parts I have are already off the vehicle... How do I tell which is left/right for the backing plates (specifically front backing plates)?

[TeZZaP]

I have wire-brushed back and managed to get a couple of numbers off the backing plates, the rear plates are clearly numbered and have an 'L' and 'R' as part of there numbers. Unfortunately only one of the fronts appear to have an 'L' as part of the number... anyone know how to tell left and right front backing plates apart?

[dandlandyman]

Trial fit a cylinder to the backing plate. The bolt holes should line up only if it's the right one for the plate. The bore of the top cylinder should face towards the front of the vehicle, and the bottom backwards. The snail-cam adjuster should be in 'front' of the cylinder. When fitted to the vehicle, the cylinders must be at the top and bottom of the plate. The cylinders on one wheel are identical, the other wheel's cylinders are the mirror image.
A digital camera would probably clarify what I'm saying, but I hope this helps.

Dan.
69 2a 88" pet4, 74 3 109" pet4, 68 2b FC pet6.