Beefing up rear disc's

[RGK]

Hi,

I have put 300tdi axles onto my Defender 90. My intention (in the future) is to increase the bhp and offroading/ expedition equipment. In which will increase the load on the brakes.

The current 300tdi front disc's are non vented, therefore rather the converting the front callipers to vented and before I sell the redundant 2.5na axle I thought of improving the current rear 300tdi discs with the front discs & callipers from the 2.5NA.

Is this possible and practical?

Can the existed 2.5NA brake cylinder & servo handle it?

Thanks.

[western]

don't bother with vented disc on rear, upgrade the fronts to vented, but the vehicle will not stop any quicker, the vented disc will just be able to dispose of the generated heat faster than a solid disc, stay with the standard disc on rear, fronts do about 80 percent of the braking anyway.

the existing servo & master cylinder won't know any difference, but if the master cylinder is quite old it would be worth replacing it with a good brand new one.

[ejparrott]

Upgrade the front not the back, under heavy breaking the back axle effectively gets lighter, so stronger brakes will only lock it up.

[Tanuki]

As a first step go for vented fronts, standard non-vented rears: but make sure you don't have any sticking caliper-pistons and you're using brake-pads from a reputable supplier [not Chinese-Ebay low-rent pressed-camel-dung stuff: you need Ferodo or Mintex].

Make sure you change the brake-fluid regularly [like every year]: it absorbs water from the atmosphere and can lead to much "OHMIGAWDWHEREARETHEBRAKES!!!" bowel-loosening nastiness when you are doing an Alpine descent with a loaded trailer on the back.

If you fit vented discs at the front, pay attention to cleaning them after any wading in muddy conditions: the air-channels in the vents can easily get stuffed with mud and then your vented-discs are not-vented discs. . . .

[200tdimorgan]

I've got 110 front calipers on the back of my 90 with salsibury axle and it just locks up with any heavy braking. It's great when towing as all the weights at the back then so it stops. Also handy for the effects of a handbrake turn, slam on and your facing the other way

[robertspark]

What about grooved and cross drilled front and rears?

[Litch]

Yes, they are ideal.

I replaced the discs & pads on my 90 last year, vented / slotted / drilled on the front and slotted / drilled on the rear all fitted with Mintex pads.

Stopping performance is terrific.

[Nigelw]

I went the other way with the Disco, stayed solid and just paid a higher price for top quality discs and pads front and rear, after replacing the fluids and finally getting a solid pedal I found that after the initial "oh f@#k" from the lack of bite from the pads into the disc, I found that once bedded in they were fantastic and can lock all 4 wheels to a stop quite easily, although I try never to use the brakes as I find it such a waste to spend all that energy gettting up to speed, then to need to generate all that heat slowing down is counter productive.

[Bowie69]

TBH, LR disc brakes are very good anyways, and designed to already work for towing 3.5T, so I can;t see why you need to upgrade for expedition/offroading at all, BHP increase, yes, but you could just not out-drive a top-heavy 4x4 in the first place.

Grooved and drilled discs actually stop more slowly due to lower contact area, and the grooves and holes just fill up with mud and make them useless -not worth it if you ever go off-road.

[ejparrott]

I can't see the point of groove and drilled discs...all i see is lots of little areas to trap grit and muck that then just chews away the pads.

[zim]

And to top it all off, if you really really wanted to upgrade the rear. Put on a set of front 4 pot calipers. But they will lock up unless you drive around all the time in difflock.

Have you got the bigger 4 pots on the front ?

Don't worry about the solid rear discs. And ditto all the comments about vented fronts.

G

[Oakmaster]

SO if you have an older 110 Truckcab - Pick-up with a V8, and had already put vented discs and EBC pads on the fornt, but it still had drums on the back axle, would your advice be not to bother upgrading to discs all round?

[Bowie69]

Disc vs Drum brakes have obvious advantages, so yes I would recommend this, but no need to go over the top.

[ejparrott]

I would do it on the maintenance front, but performance wise with a TC which has no weight on the back, you'll see no improvement to the stopping power

[vulcan bomber]

SO if you have an older 110 Truckcab - Pick-up with a V8, and had already put vented discs and EBC pads on the fornt, but it still had drums on the back axle, would your advice be not to bother upgrading to discs all round?

I swapped my 110 from Drums to Discs just by swapping axles, it doesnt stop any better and I didnt expect it to, it doesnt need me under there every 5 minutes mucking about with them however, which is good.

[RGK]

Thanks everyone for your posts.

I'm currently using the 300tdi disco axles on the 90, therefore solid disc's in all corners.

Great points raised, especially over sizing the rear thus locking them up when under weight...as most of the driving will be onroad thetefore minimising the 'oh duck, mother duckkkkkker,....' moments of dispear in front of the kids will win me brownie points with the wife.

I believe to convert the front to vented discs will be expensive compared to the performance gain...plus vs/ or alternatively... applying decent pads with drilled/ vented solid discs all round is a cheaper option with near same results.

However are drilled and vented discs really a major issue when offroading ie collection of stones in the holes thus destroying the pad & disc?? An interesting topic

[ejparrott]

Oh yes, they do fill up, and yes they do kill the pads very quickly if not washed out - given soggy slurry wet conditions of course, dry as a bone all you'll get is dust.

Vented disc conversions require new discs and callipers, drilled and groove just new discs.

Vented disc will not improve the on-the-spot stopping power, but will reduce the likelihood of brake fade if you were bring three tons down from Ben Nevis - I would imagine drilled are the same