Series 2 Zeus front disc brake conversion

Wow what a transformation, just done a 90 mile round trip and the brakes are great, can't wait to do the rears not that it needs them but just for easy maintenance

Won't be for a while though till i save up the pennies

Hi,
If i was looking to buy a classic,t&t exempt land rover like ours to drive for pleasure the brake upgrade would be a definate plus,the lack of servicing another,i am sure that you have increased the value by much more than the price of the parts,on mine the overall condition and location of the vehicle did not warrant the expense but for modern road use your system is what is needed,
atb
R

rynner said:

Hi,
If i was looking to buy a classic,t&t exempt land rover like ours to drive for pleasure the brake upgrade would be a definate plus,the lack of servicing another,i am sure that you have increased the value by much more than the price of the parts,on mine the overall condition and location of the vehicle did not warrant the expense but for modern road use your system is what is needed,
atb
R

Click to expand...

Yeah

Hi, I’m thinking of changing my 200tdi series 3 to discs and was wondering can you get away with running the standard 16inch wheels or do you have to change them, this would be for the Zeus kit. I need new tires so was wondering wether I would need to change the wheels at the same time.
Thanks,
Edward.

No chance they'll fit standard rims. The caliper is in the same space as the wheel well.
Wolf, or modular.

Wildefalcon said:

No chance they'll fit standard rims. The caliper is in the same space as the wheel well.
Wolf, or modular.

Click to expand...

Ok where would be the cheapest place to get a set of 5 wheels and tires?

Zues are very clear that STD wheels don't fit. Having recently changed from STD LWB rims to Wolfs I can see why. Its not the rim width its the shape of the wheel dish. The STD wheels are desinged to fit around a drum not clear a caliper. The Wolfs are much flatter. Your choice is modulars or Wolfs, modulars are much cheaper 2nd hand.

rob1miles said:

Zues are very clear that STD wheels don't fit. Having recently changed from STD LWB rims to Wolfs I can see why. Its not the rim width its the shape of the wheel dish. The STD wheels are desinged to fit around a drum not clear a caliper. The Wolfs are much flatter. Your choice is modulars or Wolfs, modulars are much cheaper 2nd hand.

Click to expand...

Sure I need new tires as well so I will probably buy new just need to find some cheap enough. I will probably go for modulars as I prefer the look.

Just noticed this on the paddocks website, its cheaper than modulars:
(as a guide, I paid £420 for tyres and £140 for used rims which is £560 so this is a good deal)
https://www.paddockspares.com/235-8...writing-on-the-inside-clearance-set-of-4.html

rob1miles said:

Just noticed this on the paddocks website, its cheaper than modulars:
(as a guide, I paid £420 for tyres and £140 for used rims which is £560 so this is a good deal)
https://www.paddockspares.com/235-8...writing-on-the-inside-clearance-set-of-4.html

Click to expand...

Thanks I’ve also found some cheap ones from Craddocks. Looking for 5 though as I’ll want a spare as I’m using it as a daily driver. I am waiting for responses as everyone is closed at the weekend.

edtopp1 said:

Thanks I’ve also found some cheap ones from Craddocks. Looking for 5 though as I’ll want a spare as I’m using it as a daily driver. I am waiting for responses as everyone is closed at the weekend.

Click to expand...

The modulars dish away from the calliper so no issues

Hi all, sorry to drag this thread out of the depths from last year.

To those of you who have fitted this kit - where is the brake fluid line input to the caliper in relation to the bleed nipple and wheel in terms of clearance?

Secondly - what master cylinder did you use for disc brakes front and drums rear? I have a LWB S2a, running a defender pedal box and servo with a series master currently.

My kit arrives in the next week or two (3 week lead time) and I'm intending to fit braided lines from the chassis rail straight to the caliper.

I will run the line looped around the same way as it does on the military spec from chassis to swivel top but instead of terminating there and connecting back to hard line on the swivel, planning on just using that bracket location as a place to clip the line into place, and then carry onto the caliper and meet it with a 90 degree fitting or banjo.

Why bother? So that i can remove the caliper with 2 bolts and hang it out of the way to do any sort of remedial works to the brakes or hub assembly and not have to add brake bleeding to most hub tasks. Also good to move away from rubber lines as they seem to turn the fluid a shade of black in just over a year.

From my research so far this line will be approx 625mm long, with 3/8 UNF x 24 TPI bulkhead male at the top - with probably a 3/8 banjo and 3/8 UNF x 24TPI banjo bolt - and a rubber sleeve half way down for clipping it to the top of the swivel. HEL supply custom lines like this.

Any comments or pictures of your calipers fluid inputs appreciated. Doesn't seem very easy getting this sort of info from Zeus.

If you're unhappy with the doubtful rim choices, Zeus push on you, you're not alone. There's Heystee kits, these kits will take stock rims or even FC/One ton 569204/ 569203 if you've got those.

I'm fitted discs to mine, front and rear. On a 109 I used a Defender pedal-box/Servo with a proportioning valve by Wilwood. I'd think those of you 'lacking-length' will truly need the Wilwood. That missing 21" means, you've less to stop the up-end effect, and/or too much force will go rearward. An 88 is less stable and under braking, goes 'squirelly' quicker, thus you'll more to get spot-on. Either way, to get it 'right' you'll need to fine-tune, and that'll be where a Wilwood comes in. It doesn't need to be a Wilwood, that same valve seems to come up under various brands. If you've drums on the rear, it'd be wise to get a Residual Valve on the drums... no LR MC has one, and they should. Semi auto-adjusts without falling back to the snails which is good.

Does the rear brake pressure requirement change at all between loaded and unloaded vehicle?

109SeriesIIA said:

If you're unhappy with the doubtful rim choices, Zeus push on you, you're not alone. There's Heystee kits, these kits will take stock rims or even FC/One ton 569204/ 569203 if you've got those.

I'm fitted discs to mine, front and rear. On a 109 I used a Defender pedal-box/Servo with a proportioning valve by Wilwood. I'd think those of you 'lacking-length' will truly need the Wilwood. That missing 21" means, you've less to stop the up-end effect, and/or too much force will go rearward. An 88 is less stable and under braking, goes 'squirelly' quicker, thus you'll more to get spot-on. Either way, to get it 'right' you'll need to fine-tune, and that'll be where a Wilwood comes in. It doesn't need to be a Wilwood, that same valve seems to come up under various brands. If you've drums on the rear, it'd be wise to get a Residual Valve on the drums... no LR MC has one, and they should. Semi auto-adjusts without falling back to the snails which is good.

Click to expand...

Thanks for the response, good to hear that the proportioning valve is needed for dual discs, I was on the fence about ordering one, do you think they are needed for drums in the rear or just dual disc conversions? Ive had them on cars before so familiar with operation and install.

Master Cylinder: Heystee list the BR 3225A(NRC9529A) or another forum mentioned BR 3235(NRC8690) both are for early defenders with drums and discs - which do you use for discs all round? Any suggestions for which model for disc/drum set up?
https://www.bearmach.com/product/wheel-cylinders-brbhbhwc/brake-master-cylinder-br-3225a/BR 3225A
or
https://www.island-4x4.co.uk/master-cylinder-8391-ferodo-nrc8690g-p-25051.html

Rear Brakes: I am keeping drums on the rear for the time being – long term it would be good to have discs on the rear. Maybe this kit will help a good rear brake set up.
https://lofclutches.com/shop/brakes/brake-kits/series-2a-3-10-rear-brake-kit-1971-85/

Residual Valves: Interesting what you say about Residual Valve’s, I havn’t used them before. Would you suggest one per side or one for the whole rear circuit? I was of the understanding that the snail adjusters brought the shoes close to the drum but with enough not to drag – wont a Residual Valve cause the brakes to drag? Wilwood seem to think 2psi for discs or 10psi for drums. Another thought is that even the best of these wheel cylinders like to leak, I wonder if residual pressure will make that even worse…
https://www.demon-tweeks.com/uk/wilwood-residual-pressure-valve-499824/

Wheels/Heystee: I was originally a bit dubious about not having the series wheel rims any more but having had modulars on for the last 3 or 4 months I'm used to the look now, and the fact they are tubeless and wider, its function over form in this department for me. The heystee kit just adds up too quickly and using branded parts comes in circa £1500 so I went for Zeus.

Braided Lines: I managed to get through to Zeus today and they said that the caliper isn't suitable for a banjo so i've ordered braided lines from HEL with a 90 degree swivel 3/8" UNF 24tpi for the caliper and the same thread bulkhead male at the chassis end, 630mm total length. Rear is same as stock plus 3 inches to allow for future travel mods.


Andy

>>The rear must grab first, to keep you straight

This is dangerous advice.

Rear axle locking must be avoided at all costs - so, the braking on the rear axle must, even in the worst case conditions, be reduced to make sure that the front axle locks first.

Rear axle locking will result in a loss of control of the vehicle, with the rear axle overtaking the front axle very quickly; often so quickly that the driver cannot react (especially in an emergency braking situation!)

Section 3 of the relevant vehicle design legislation, UN ECE R13 describes this in terms of adhesion utilisation, but, the practical interpretation of adhesion utilisation is that rear axle locking must be avoided, and manufacturers must demonstrate this in order to obtain type approval.

Tall Ratbag said:

>>The rear must grab first, to keep you straight

This is dangerous advice.

Rear axle locking must be avoided at all costs - so, the braking on the rear axle must, even in the worst case conditions, be reduced to make sure that the front axle locks first.....

Click to expand...

I wrote: Reading many brake threads, including this one, it's clear the bulk don't understand them, which is worrying. And that's it right there^^^.

With words not written or implied. TR, went off on a tangent,. Better he understands my EXACT words, and reads those again. Correctly set-up, the rear will time to grab/apply first, however, which axle locks first... is about bias. There is a substantial difference. That TR is unable to see the difference between timing and bias, or why this timing is required, is worrying. It sailed over his head. Made worse by having had it part-explained and still not getting it.

Again, we align the vehicle by application of the pressure to the rear circuit first, ahem... milliseconds later, both axles are braked, the bulk of the forces are put the front. We will try not to lock-up, but if anything does lock-up, it should be the front. Thus, we 'time' the rear to 'grab' first, we bias the front to take the greatest force, and if something does lock-up, it won't be the back. It won't be the back, because we read and we understand brakes. We understand why it's desirable for rear brakes to grab/be applied/timed to operate first. //Patronising off.



If you are wondering how the rear is timed to apply first, here is a X-section of a typical twin-circuit MC. In order for pressure to build in the pipe furthest from the pedal/push-rod, pressure in the circuit nearest the pedal/push-rod must build first. Can you guess which circuit is which? And which circuit grabs/applies first?

Answer: That might depend on which of those springs is stronger, which in turn is a factor in setting bias as well. We can be sure the timings will differ. This is why it can't be always be taken for granted, 'the rearmost pipe is intended for the rear circuit'. On one LR master-cylinder in particular it isn't. Herein is the root to the bias and timing pre-set by the MC. Because in the case of a Zues disc-conversions, we can't use the factory front/rear bias pre-set by the MC - [you'll start ot understand why about now] we use a prop. valve to get as best we can. A very sound reason to use the Heystee kit is... if we can find a factory G-valve, great. that'd help. Only we're forgetting a Zeus kit for one will require a different bias match to the factory/Heystee kit, thus the factory G-valve won't be ideal. To get the correct bias, and timing via the MC, the Zeus kit forces a prop.valve.

If there's one thing we all need to understand on our vehicles it's brakes.

Tall Ratbag
3/10 See me.

Many years ago when I first learned to ride a motorbike I was taught to apply the front brake first. This was so weight transfer to the front wheel took place before you applied the rear brake and prevent locking rear wheel.