rr classic brakes?

[w_heily]

ar e there any good upgrades out there ive upgraded to hydroboost brake booster which runs off the powersteering pump

but im wondering if there are any disc brake upgrades etc

[Highway_Star]

I've never thought the brakes were lacking in all honesty, unless they aren't healthy.

Brembo vented discs, green stuff pads, make certain the calipers are spot on, same for the lines. Change the flexis for braided Goodrich ones.

[bishbosh]

I agree with Mr Star - RR brakes in good shape are excellent.

Stay away from grooved / drilled discs if you intend to off road a lot though as they will eat pads extra quick.

[w_heily]

My ones an 83 always had poor brakes want to upgrade a bit mainly because i put a chrysler big block with a 727 auto and lt 230t and ive got 110 county difs for it

[g&t]

I think it's a question of what you expect from a vehicle of such an old design. I've always found RRC brakes 'adequate' for the job, considering how you (dare I say) should drive these vehicles whose handling will never compare to a modern car. If I had used the brakes in the same way on my old BMW, or our current Mondeo, it would only be the seat-belt stopping me going through the windshield!

[sheltie50]

I think it's a question of what you expect from a vehicle of such an old design. I've always found RRC brakes 'adequate' for the job, considering how you (dare I say) should drive these vehicles whose handling will never compare to a modern car. If I had used the brakes in the same way on my old BMW, or our current Mondeo, it would only be the seat-belt stopping me going through the windshield!

While your point is well made, The brakes on any R/R should be able to stop on a sixpence, if it cant something is wrong.

[FridgeFreezer]

My ones an 83 always had poor brakes want to upgrade a bit mainly because i put a chrysler big block with a 727 auto and lt 230t and ive got 110 county difs for it

110 county diffs being, erm, exactly the same ratio as RR diffs or have you upgraded because of the salisbury rear axle?

As has been said, RR brakes were always pretty good, if they're not then something's wrong. It should be able to stick your face to the windscreen or break traction, whichever happens first (very tyre dependent).

[ThreeSheds]

Agree with all above - if the RR brakes are in good condition they are lovely - controllable and powerful. However if you are modifying the vehicle for 'spirited' road driving then you may want to change to the later front discs which are vented and heavier (more thermal capacity). In terms of initial stopping power they won't be any different - just less likely to fade with repeated heavy use. The other modification that is well worth doing is replacing the rubber hoses with PTFE/braided ones - makes a huge difference to the 'feel'.

HTH

Roger

[landybehr]

Well, I´ve had some succes in using 110"/90" front callipers on the font axle. The have 25% more hydraulic effective area so by the same amount they lessen the effort for you to press down the brake pedal - or OTOH provide more clamping power by that 25%.

I was able to stop with the original setup - and experienced bad brakes usually when there are sticking pistons (try to press down the pedal really hard while standing - when the next braking action is significantly better than the one before that maneuvre you´re likely to suffer from sticking pistons - which calls for a calliper overhaul or new callipers (usually the latter being more economic)).

Anyway, I was after comfort when I read about someone else using the 110" calliper and immediately converted my rig.

On my RRC (´89) they were a direct fit. Even the brake disc can stay. But you have to take care of whether the bolts to mount them are metric of imperial thread (depends on MY of the RRC - there are imperial/metric callipers for the 110" to suit). And I had to "simplify" the brake circuits to only one line to each calliper (instead of two lines to the front - as there is no 110" with duall lines). So some modifications to the brake lines is necessary, but that´s easy to do. Unused lines could be blanked off at the master cylinder with bleed nipples, I guess, but I bought a corresponding master cylinder from the Disco1 (as the old master cylinder was some 15years old anyway).

[landybehr]

p.S. I didn´t consider ABS brakes. I have no idea if larger callipers would work with it. But I´d doubt it; the Wabco-ABS more than likely doesn´t need to be modified anyway.

[Range Rover Blues]

The Disco ABS system is single line to each front wheel, I'd thought about retro fitting it but TBH even with 238/85 I can still lock up the wheels.

[landybehr]

I´d argue with comfort. Both callipers are well able to lock the wheels. But with the 110"/90" front brakes even your wife will manage

AFAIK the master cylinder has the same bore irrespective of RRC or Defender. So a RRC master cylinder is up to the job.

[Range Rover Blues]

AFAIK the master cylinder has the same bore irrespective of RRC or Defender. So a RRC master cylinder is up to the job.

It's not just the bore, the RRC master cylinder controls half of the front callipers and the back ones form the primary circuit and the second half of the fronts from the secondary

the Disco/Defender system controls the entire front on the primary and the rear on the secondary. I can't say if they are a different part or not but if they are it is possible the internal springing is different between the RRC and Disco master cylinders because they displace different volumes of fluid into each hydraulic circuit.

Just a thought

[landybehr]

to my knowledge the bore is the critical point to take care of. If I changed the diameter by my own, I would worry about altering the "transmission ratio" between master cylinder and callipers. Given that the mastercylinder would have a piston of twice the surface of the callipers, I would have vastly reduced the pedal travel, but it would that far more effort to press the pedal. If I reduced the bore of the master cylinder, the opposite effect would take place. So the Defender´s brakes (with it´s larger calliper pistons; 25% more surface) could have led to a 25% (I think) reduced effort to push the brake pedal, but may have increased the necessary pedal travel beyond limits of the master cylinder. Therefore it is good to know that the master cylinders of both LR-models have the same bore.

AFAIK the master cylinder of the RRC differs in that is has 2 more connectors/bungs to serve the 2 extra brake lines that are there for the "split" system that you described. Internally there is no real difference. The springs are there to seperate the two pistons of the master cylinder, probably to position them right (to take enough fluid for the next braking) when the brake pedal is released (or whatever). I thought about blanking off the "now unwanted" 2 connectors of the RRC master cylinder but, as said, chose a Discovery1-master cylinder instead (which only has 3 connectors - 2 to the front, 1 to the rear axle).

[cackshifter]

ar e there any good upgrades out there ive upgraded to hydroboost brake booster which runs off the powersteering pump

but im wondering if there are any disc brake upgrades etc

What bits did you use exactly?

Nigel

[Range Rover Blues]

I certainly agree that the diameter of the master cylinder, along with the ratio to the slave or wheel cylinder is important. It direclty effects the ratio of pedal effort to braking effort and pedal travel.

Thing is when the system is working it is all powered by the primary piston seal, the secondary piston is driven by the primary hydraulic pressure. If one or the other circuit fails however then the internal springs come into play. With the amount of fluid being consumed by the primary and secondary circuits being different between the 2 layouts of braking circuits I would want to be sure what the implications of changing would be, that's all.

[landybehr]

I would want to be sure what the implications of changing would be, that's all.

which is certainly a wise approach. To be honest I got around any doubts by taking a Disco1 master cylinder.

OTOH I thought the pistons in the master cylinder have a central pin at each end that usually wouldn´t contact each other but to so when circuit fails to take care that the remaining piston will move within it´s working range (i.e. not being moved by the primary hydaulic compartement but by the pin instead). Anyway, you see I took the "safe" way.