Defender 90 Brake Upgrade Suggestions

[NRS91]

Hello Gents (and any ladys lurking here)

I have a 200+hp 1987 LR90 with a 500kg Cummins 6BT engine and 37" tyres...

this combination has made the standard brakes (Td5 90 axles) next to useless (they will lock up but theres nothing much inbetween nothing and locked)

i have just fitted a new lucas servo from a 110 and has helped slightly but now need more improvement just for slowing down in a more gradual and controlled manner

i was looking at these:
http://www.rimmerbros.co.uk/Item--i-RA1357
http://www.rimmerbros.co.uk/Item--i-RA1359

any other suggestions before i get fed up and fit air brakes? haha

[Aragorn]

For starters you will want to upgrade to the later spec servo and master cylinder. I'm not sure if you've already done this or only changed the servo? The later MC has a bigger bore, and is matched with larger caliper pistons.

If you want to stick with factory parts, then you'll want to install later 46mm 110 calipers all round, this gives you vented front disks, slightly larger rear disks, and bigger 46mm pistons as used on all the defenders from ~300tdi onwards. Personally i dont rate fancy drilled and grooved disks, they dont do much for performance, its more just a style thing. Good pads however will make a difference, though its arguable whether greenstuff are actually any good. My personal favoured road pad is Ferodo Premier.

The result of all that lot, will be less pedal effort required to generate the same braking force, and thus everything becomes more controllable as your not heaving on the pedal with all your might.

The issue you may have though is simply traction. It may well be that your tyres simply arent very grippy on tarmac (presumably being 37's they're some extreme offroad pattern?), and thus lock up very easily. If thats the case, fitting larger brakes wont make a difference, infact they'll just make it even easier to lock the wheels!

[Frax]

I fitted drilled and vented discs + green pads over a year ago and run 35" tires, they did work but the green pads did not impress.

They did not wear much but they did go like a hard rubber which blocked all the groves and holes in the discs.

[Aragorn]

The hole blocking is fairly common with drilled disks, regardless of pad used. The drilled disks can also crack, and the grooves can make the brakes very noisey under heavy braking.

I stick with plain disks for these reasons, plus they're cheaper!

[Retroanaconda]

Buy a set of 110 front calipers (or a spacer kit for your current front calipers) and a set of 110 rear calipers. Put your front discs on the rear (or new ones if they're old/worn), and get a set of vented discs for the front. Your master cylinder should be STC441, which is for all non-ABS 90/110 from 1991 to 2006. Then a decent set of pads, Ferodo/Mintex etc.

That will give you the full 110 braking system, you shouldn't need anything more than that. Grooved/drilled a waste of time as above, especially if it's used off road - then it'll really wear your pads down quick!

I suspect Aragorn's point with regard to tyres is the biggest issue though. Large tyres reduce the effective braking effort and off-road patterns will of course make it very easy to lock up.

[Landrovernuts]

Agree with what has been said in the above posts, big piston 110 calipers make a big difference, however not so sure above putting front discs on the back as they will not fit unless you use front calipers on the back and even then you will have to alter the mounting brackets on the axle. Something I looked into ages ago (Iwas looking to fit vented discs on the back for another project), but when I found out about having to alter the axle mountings, I left well alone!

Agree with the pads also, had a set of greenstuff pads on my 90 and hated them. I did like the old Pagid pads, but have not seen them for ages as they were quite soft and bit the disc well even when cold. You could say that they wore out quicker than other pads, but I used to prefer changing pads to discs (they were really disc friendly). So totally agree with decent Ferrodo/Mintex pads incidently I had a trip around the Ferrodo factory in the Czech Republic last year which was quite enlightning as they have 42 different friction material blends and heat treatments depending who they were manufacturing for.

I also think the big thing here is available traction of the tyres and have to agree with the above. Try (if you can) some normal sized all terrain tyres and think you will notice a difference as pointed out the braking effort is increased with larger tyres and road grip reduced with mud terrains especially when wet. While in good condition Land Rover brakes are very good, but just remember you have half a ton of truck engine over the front axle which is bound to have a slight effect also!

Toby

[Retroanaconda]

Front discs for a 90 (and early non-vented 110) is the same as rear disc for a 110. Just saves him buying new ones if his existing ones are OK. Obviously you have to change the calipers to 110 rear ones as the discs are bigger than a 90 rear, but the mounting is the same.

He won't gain any braking power from what I suggested (well a bit at the back, but that wouldn't really be noticeable), with Td5 90 axles he already has 46mm pistons on the front. The only difference between 90 and 110 at that age is that 110s had vented as standard.

[heath robinson]

I think that the tread pattern has more to do with it than the size. For one, if you've ever driven a selectable 2/4wd pickup (in my case a ford ranger and a hilux. I know, I'm a traitor of the blackest order) with an AT tyre on, then swapped for an MT, you'll have noticed how much more grippy the ATs are. Both of the above trucks were a massive laugh with the MTs on, the back comes out without too much provocation.

As a second point, our Daf 4x4 stops fairly promptly on it's rubbish bar-grips unladen. Same engine, but about 4t of extra truck, and air brakes. The tyres on that are 12.00r20s so probably thinner than yours, but bigger at about 44". The bar grip tyres aren't all that in many ways, but the tread blocks are too big to cause much MT-style brake squirm, and it doesn't lock as easily as I expected it to when unladen.

I guess my point is that big isn't the issue once the brake system's controllability (which spellcheck seems to think is a word, even if it feels a bit thick on the tongue) is sorted, it's probably more the tyre pattern.

As a theoretical question, is there a way of retrofitting ABS? I noticed that my mate's ABS-riddled shiny 110 stopped a fair bit more promptly than my old 110, on the very same wheels and tyres, 225/85 BFG MTs on 1ton wheels.

May I also say that your truck has completely ruined my ability to focus on rebuilding mine as I intend! All I can think about now is a cummins-engined portal-axles lwb series pickup. The noise your thing makes is sublime!

[Retroanaconda]

I'm sure you could retro-fit the whole ABS system from a Td5 Defender without too much issue, as it's a standalone system without any CANBUS silliness. It might be easier to fit your car to the ABS system though!

I hear they're a bugger to bleed as well, and the valve blocks etc. are not cheap even second hand.

[NRS91]

interesting ideas gents!

the 37s are Cooper STTs so grippy enough... i just want more feel to scrub off speed gently without slamming the pedal down lol

[muddy]

Exhaust brake.

[mcc1979ian]

Never mind the exhaust brake just go the whole hog and fit a 3 stage retarder!!

[landypc]

Hi,

I've completed an upgrade for my TD5 90.

I used these and the braking improvement is fantastic:

EBC yellow stuff pads front and rear (go direct to EBC cheaper http://www.ebcbrakesdirect.com)

DP4708R front and DP4294R rear

BDA

front 4086XS and rear 4088XS (use Clarke Motor Sport cheapest for these anywhere)

Upgrade your brake fluid to one of these

Castrol SRF, Motul RBF660 and Gulf RF1000.

You only get what you pay for the discs are a little expensive but well worth it.

I did alot of research into my brake upgrade.

Before any purchase check ot the diesel tuning companies and see what they are listing.

Alive use DBA but not the ones I've used. I contacted BDA and found a disc that out performs the ones listed by Alive tuning (see above)

Brake pads are down to you. Once again Alive tuning list Ferodo but my enquiries with them were futile and never received an answer.

Make sure you have all the correct tools, seals and nuts (axle I.D. etc) before starting.

Plenty of brake cleaner.

Shed loads of copper slip

Take ya time taking it all apart using a good manual, clean as ya go and reassemble.

If you have any debt about a part or reusing one, then don't, get new and replace every time.

Money well spent on ya brakes never fails.

Lastly

BED THEM IN CORRECTLY

Good luck

landypc