Thread: 92'RRC Brake Upgrade

Originally Posted by trobbo

it's really really pretty and if you shine a green light on it it will do something really funky

Thanks for the helpful post. Perhaps I should be more specific....
My background is not 4wding, thought I am a keen inductee to the practice. I understand the theory of a proportioning valve, in terms of balancing the pressure provided to front and rear axles, normally for the purpose of providing more pressure to the front, less to the rear, so that rear brakes dont lock up as a result of having less load on them.

So, having said that, was the suggestion that the rear proportioning valve be adjusted, removed, or is it indeed to see how pretty it is under a green light (smart arse).

Im not sure I was clear before in describing the scenario. A pretty gnarly, very steep track, just (like 1 minute) after having had a 30 minute break at the top, going at less than 5 km an hour. So brakes werent hot (but not cold) speed not a factor, but pushing pedal to the floor, car wouldnt stop, just maintained about 2km an hour.

I wouldnt think vented disks would matter in this context, but im not an expert. Will they really?

Then the advice seems to be callipers, and shining a green light on the proportioner.

Mmmm ever thought about vacume the brakes need vacume assistance , Not familiar with the wabco set up , i guess its a electric vacume pump ?

Smells of either siezed caliper or more or lack of vacume assistance in my opinion

Originally Posted by Hamish71

car wouldnt stop, just maintained about 2km an hour.

I'll go out on a limb here .... Have a look at your / mates Callipers .... I recon they are a 1 piston style , verses the defender which I believe is a 2 piston set up

If you have a look at pad replacement pics, I think you will find that there are different pad sizes (more surface area) ....

Also, Oil contamination will stuff pads up quickly, so check or ask ya mate about the history of oil leaks

A little hint on the next time you have a "runaway" .... There is a hand brake that you can use .... Just hold the release button in and slowly pull it up to help control the ride, and to add some extra stopping power (assist the main brakes) ... as it will act in the same manner as a "engine brake" ... but don't "ride" the hand brake as it will overheat quickly. (+ Don't reef the hand brake as you very well snap uni joints, and that will mean no drive train)


Mike

Originally Posted by Hamish71

Thanks for the helpful post. Perhaps I should be more specific....
My background is not 4wding, thought I am a keen inductee to the practice. I understand the theory of a proportioning valve, in terms of balancing the pressure provided to front and rear axles, normally for the purpose of providing more pressure to the front, less to the rear, so that rear brakes dont lock up as a result of having less load on them.

So, having said that, was the suggestion that the rear proportioning valve be adjusted, removed, or is it indeed to see how pretty it is under a green light (smart arse).

Im not sure I was clear before in describing the scenario. A pretty gnarly, very steep track, just (like 1 minute) after having had a 30 minute break at the top, going at less than 5 km an hour. So brakes werent hot (but not cold) speed not a factor, but pushing pedal to the floor, car wouldnt stop, just maintained about 2km an hour.

I wouldnt think vented disks would matter in this context, but im not an expert. Will they really?

Then the advice seems to be callipers, and shining a green light on the proportioner.

I may not be much help here but will try.

The vented disk heat up far quicker than solids. Hence solid are better at low speed. The vented also cool quicker so its a trade off. I personally have found the solid disc better for low speed work.

The Defender calipers have more displacement there for more leverage. This then will affect the ratio of the front to rear braking.
In my set up I run a update Disco 1 master cylinder. (Mines an 89 Model)
I have found I can get away with removing the proportioning valve when mostly off road as the brake are useless to you going backwards. I have had no dramas with locking up the rear end on the black top. Some others use an adjustable proportioning valve of a japper ute.

Other thing is, if running an auto, I find when the idle speed is up a bit it will push you wile in low range.


I'm only a dumb farmer these days so some one may correct some of this a bit Just trying to help

BTW, I have had very little to do with the wabco set up, so you may be restricted in what you can do.



If you search for long enough past the "cow girl" linky, you should eventually find the answers your looking for.

Tony

Originally Posted by Hamish71

OK, I have done searches on Classic brake upgrade, defender calliper(s), etc, and cant find an answer to my questions.

Specifically:

1. is the TRW Lucas brake pad a siginificant improvement over others?

2. is the defender calliper a significant upgrade over RRC calliper, and why?

Hamish71

Defender front calipers use a slightly larger pad than the RR calipers. IMO the best combinbation is Disco 1 brake plumbing master cylinder and booster, with Disco 1 rear calipers and Defender front calipers with vented front discs. I fitted vented front discs to my Disco 1 which significantly improved brake performance. My Defender stops exceptionaly well with genuine pads and good quality discs.

If you converted your RR to D1 brakes (M/cyl, calipers, and plumbing utilising vented fronts (the calipers would need spacers fitting) I think that you would be quite happy with the result.

I recently had my RR Classic fitted with a standard booster retaining the original claipers - it does not stop nearly as well as my D!

I hope the above helps.

If you would like to discuss matters further PM me a phone number and I will give you a call.

Christopher

PS I have had a serious look at Landrover brakes

PPS Does your RR have ABS? Mine used to - deadly in the bush as it would not stop in certain circumstances hence reversion to non-ABS set up.

Just a few comments from a 92 non ABS RRC driver.
1 brakes get hot very quickly in low range down hill. And do not underestimate the time it takes for cool down.

2 The auto will push UP TO 1500rpm when the injectors will be cut off. So if it is safe let it go to 1500RPM and you will get much more engine braking. This is similar to the feeling AFAIK of Hill descent, when you think "uh oh" but you can be sure it will happen.

3 As detailed before judicious use of the handbrake is helpful.

4 In extreme emergency and going slowly AND for less than a few hundred metres , the auto can be put in reverse and it will provide LOTS of engine braking. This very quickly overheats the torque converter so is emergency only.

It sounds to me like the brakes were overheating. I have fitted EBC pads to mine but they are not the green stuff or yellow stuff. They have made little difference . The green stuff are promoted by EBC to have much more friction but I have yet to test them as they are EXPENSIVE and reputed to wear out discs very quickly.

RRCs seem to have insensitive brakes. I have had the experience on seeing a drop off to a river bed with my trailer on, of not being able to slow enough. I have new front discs and new master cylinder and the system has been pressure bled/flushed. No seized calipers as you can easily tell a seized caliper as the car will pull strongly in the other direction.
The next thing I will do with mine is replace the hoses but I just think they have insensitive brakes.
Regards Philip A

Slotted rotors and Mintex pads make a difference.

I have all new everything in the brake system, including braided lines. Slotted rotors in the front only. Have gone from even tyre wear all round to the fronts wearing faster than the rears and now get brake dust on the front rims as well. Will be fitting slotted to the rear.

Mintex pads seem to grip better as they get hotter, i.e. if you hold constant pressure on the pedal you can feel them grip more and more as you come to a stop. Very cheap from Paddocks.

Was going to do Dougal's Defender caliper swap but they mightn't have fitted inside my 15" rims. These calipers apply more force because the piston dia is greater than that on a RRC.

cheers, DL