Caravelle 1965
- Thread starter arak
- Start date
Just buy a VH40 booster kit off EBay for around $100. Mount it close to the master cylinder, run the vacuum hose to.the inlet manifold. Then any decent brake shop should be able to bend up the two short hard lines needed to complete the job and give it a quick bleed for you.
The booster doesn't ultimately make your brakes any better, it just reduces the pedal effort required to get the same result.
I fitted one on my Austin A30 a few months ago. I was able to bend my original master cylinder line to fit the booster and just took the brake line and fittings that came with the kit to the local Brakeland and the guy bent it and double flared it to my measurements for $10. Then I fitted the pipe and bled the system.
The Austin has a single circuit master cylinder so front and rear brakes are both boosted. In a dual circuit application you just boost the front brakes.
To quote the RWC guy when he came back from his brake efficiency test on the Austin, "they sh#t it in".
The car only has 8" front drums and 7" rear.
The booster doesn't ultimately make your brakes any better, it just reduces the pedal effort required to get the same result.
I fitted one on my Austin A30 a few months ago. I was able to bend my original master cylinder line to fit the booster and just took the brake line and fittings that came with the kit to the local Brakeland and the guy bent it and double flared it to my measurements for $10. Then I fitted the pipe and bled the system.
The Austin has a single circuit master cylinder so front and rear brakes are both boosted. In a dual circuit application you just boost the front brakes.
To quote the RWC guy when he came back from his brake efficiency test on the Austin, "they sh#t it in".
The car only has 8" front drums and 7" rear.
I agree. If things are in good order and set up properly they work quite well because the car is so light. The drivers knees and hips also need to be in good working order though I suppose.
Graham, the brakes on my R10 were rebuilt 7 years ago, using original, good discs. It had new hoses and ordinary Ferodo pads,I agree. If things are in good order and set up properly they work quite well because the car is so light. The drivers knees and hips also need to be in good working order though I suppose.
I had 2 wingers who said Renault brake were Sh*t, they never know why Renault always bragged about their fantastic 4 wheel disc brakes. I took the one for a ride in Nedlands, and broke hard for roundabouts, and one real panic stop. and when we got back I asked him to tell the audience what it was like, he turned and walked away, never to complain in my ear shot again.
If you don't know how to build Renault Brakes, leave them alone.
Ray
- Joined
- Sep 6, 2003
- Messages
- 506
Knowing that the fronts locked in extremis, I sold an R10 to a boyfriend of my sister's back in the sixties by taking a dealer demonstrator for a run with him (in the dry) & mashing the brakes.
Having just read a U.S. test of an R10 in which they photographed a crash stop with the driver's hands out of the window, I tried the same hands-off thing when the fronts had locked. Much burnt-Michelin smoke & flat-spotted tyres no doubt but a mega-short stop. He bought one.
The joys of youth & idiocy!
I like the R8/10 brakes but, like others, recommend deletion of the rear pressure limiting valve. That action almost eliminates front brake locking in the wet - the main vice of standard brakes &, owing to more difficult modulation, one that would be exacerbated with a booster.
Having just read a U.S. test of an R10 in which they photographed a crash stop with the driver's hands out of the window, I tried the same hands-off thing when the fronts had locked. Much burnt-Michelin smoke & flat-spotted tyres no doubt but a mega-short stop. He bought one.
The joys of youth & idiocy!
I like the R8/10 brakes but, like others, recommend deletion of the rear pressure limiting valve. That action almost eliminates front brake locking in the wet - the main vice of standard brakes &, owing to more difficult modulation, one that would be exacerbated with a booster.
My wife's 1956 Austin A90 has (or maybe had - it hasn't been registered since 1997) double leading shoe drums on the front, single leading shoe drums on the rear. When properly adjusted it stopped very well - the cross-ply tyres tended to be the limiting factor. Well it stopped well going forwards - just not as well in reverse (the negative issue of twin leading shoe drum brakes).
However, as the linings wore, the brakes got less effective. Because this happens relatively quickly, most of the time the brakes were not as good as they could be - no self adjusters in 1956. Presumably because the surface area of shoes and drums is so much greater than pads & disks, pedal effort is much less than (unboosted) disks, but disks have the advantage of not needing adjustment, and therefore giving much more repeatable performance.
Fitting a booster would not have been the solution - without ABS, a booster would likely make the wheels lock too easily. Getting the right tools and scheduling regular brake adjustment is the best option.
However, as the linings wore, the brakes got less effective. Because this happens relatively quickly, most of the time the brakes were not as good as they could be - no self adjusters in 1956. Presumably because the surface area of shoes and drums is so much greater than pads & disks, pedal effort is much less than (unboosted) disks, but disks have the advantage of not needing adjustment, and therefore giving much more repeatable performance.
Fitting a booster would not have been the solution - without ABS, a booster would likely make the wheels lock too easily. Getting the right tools and scheduling regular brake adjustment is the best option.
If the Renault still has single circuit brakes the addition of an inline booster will not alter the inherent braking characteristics of the vehicle. It will do everything it normally does, just with less pedal effort.
I've added numerous inline boosters and mastervacs to various model cars that never had them, and not once have the brakes been worse to operate than before, whether they be disc/disc, disc/drum or drum/drum, single circuit or dual circuit.
Export 2000TC Rovers had two inline boosters fitted, one for the front discs and one for the rear discs.
My F250, F100 and Mustang all have mastervacs added to supplement their previously unboosted four wheel drum brakes, they all have braking performance that comfortably exceeds their tyres' abilities to maintain grip on the road.
It's no different to adding a ram style power steering set up to existing steering (early Holdens, Fords etc). The car doesn't handle any differently, if it under or over steered before, it still will, but the driver doesn't have to work so hard at correcting the car while it's doing it.
You can cut intricate shapes in metal with a 2.5mm thick angle grinder disc, but it is a lot easier to do the same job with a 1mm disc. The only difference is the 1mm disc takes less effort to guide, and therefore it is easier to control.
The only logical reason not to add a brake booster would be if you were concerned about originality.
My Reliant doesn't have a brake booster, but my illogical reason for not adding one is that it will also add weight.
I've added numerous inline boosters and mastervacs to various model cars that never had them, and not once have the brakes been worse to operate than before, whether they be disc/disc, disc/drum or drum/drum, single circuit or dual circuit.
Export 2000TC Rovers had two inline boosters fitted, one for the front discs and one for the rear discs.
My F250, F100 and Mustang all have mastervacs added to supplement their previously unboosted four wheel drum brakes, they all have braking performance that comfortably exceeds their tyres' abilities to maintain grip on the road.
It's no different to adding a ram style power steering set up to existing steering (early Holdens, Fords etc). The car doesn't handle any differently, if it under or over steered before, it still will, but the driver doesn't have to work so hard at correcting the car while it's doing it.
You can cut intricate shapes in metal with a 2.5mm thick angle grinder disc, but it is a lot easier to do the same job with a 1mm disc. The only difference is the 1mm disc takes less effort to guide, and therefore it is easier to control.
The only logical reason not to add a brake booster would be if you were concerned about originality.
My Reliant doesn't have a brake booster, but my illogical reason for not adding one is that it will also add weight.
Quite a large percentage increase in weight, regarding the Reliant...If the Renault still has single circuit brakes the addition of an inline booster will not alter the inherent braking characteristics of the vehicle. It will do everything it normally does, just with less pedal effort.
I've added numerous inline boosters and mastervacs to various model cars that never had them, and not once have the brakes been worse to operate than before, whether they be disc/disc, disc/drum or drum/drum, single circuit or dual circuit.
Export 2000TC Rovers had two inline boosters fitted, one for the front discs and one for the rear discs.
My F250, F100 and Mustang all have mastervacs added to supplement their previously unboosted four wheel drum brakes, they all have braking performance that comfortably exceeds their tyres' abilities to maintain grip on the road.
It's no different to adding a ram style power steering set up to existing steering (early Holdens, Fords etc). The car doesn't handle any differently, if it under or over steered before, it still will, but the driver doesn't have to work so hard at correcting the car while it's doing it.
You can cut intricate shapes in metal with a 2.5mm thick angle grinder disc, but it is a lot easier to do the same job with a 1mm disc. The only difference is the 1mm disc takes less effort to guide, and therefore it is easier to control.
The only logical reason not to add a brake booster would be if you were concerned about originality.
My Reliant doesn't have a brake booster, but my illogical reason for not adding one is that it will also add weight.
I spent $170 on grade 5 titanium bolts to save 700 grams of weight, so I figure spending $100 to gain a couple of kilos could be considered a retrograde step.
It stops OK anyway, it has Mini rear brakes and a Triumph Spitfire front brake and is half the weight of either of these donor cars.
After deleting that valve, I wear out REAR pads as well as front ones. Never did before. That tells me everything about why the brakes are so much better now.
Yes, but haven't you increased the chance of locking the rears (and then swapping ends) in the wet? Or don't any of you drive your RERs in the wet? Certainly my son's early Hilux ute was pretty scary on a wet road - at least when it was unladen (and we never even removed the pressure limiting valve).After deleting that valve, I wear out REAR pads as well as front ones. Never did before. That tells me everything about why the brakes are so much better now.
It's never happened to me in three decades since I threw the thing away. Hilux utes were awful except for reliability and had no weight on the back. I know why Renault added the valve (there was more than one type over the years too) but don't forget they did use small calliper pistons at the rear too.
With the improved brake balance after removing the valve on the 1600 R8g, it never, ever, hinted of rear wheel lock up in the wet. As an extreme example, I ran it at a night race during wet weather at Sydney Motorsport Park (Eastern Creek) circuit where the wet braking was vastly improved, no rear lockup, quicker than about 40 of the 60 cars, including current model vehicles.
I also now run my Alconi and fast Floride without the rear valve.
I should add that the braking on a race track is on the extreme limit, threshold braking, where there is a very narrow margin for error, absolute control and reliability in the braking system is essential. That valve did not improve the wet weather braking, it was unsafe and therefore had to go. Lucky my testing was done in a controlled environment and not on the road.
Interesting that they were fitted at all, given your testing. Mind you, they were fitted on Dauphines, some of them at least. I wonder whether Dauphine drums were more prone to lockup and the valve was carried through to the disc braked cars less critically?
- Joined
- Sep 6, 2003
- Messages
- 506
My, perhaps mistaken, understanding of things is that it was compliance to regulator demands that rear brake lock-up be avoided.
Silly if so as at least one retains steering with rear lock-up, unlike front lock-up.
Silly if so as at least one retains steering with rear lock-up, unlike front lock-up.
The difference in the piston size from front to rear seems to be the correct balance without the need for the valve.
You can get rear wheel lock up if you pull the handbrake on, its called a handbrake turn. You just pull into the driveway front first at about 40 kph, then pull the hand brake on with a little lock, the rear brakes lock up and the car automatically reverse parks neatly into the garage. I guess at the point where you are almost rear bumper against the back of the garage you do regain some steering.
You can get rear wheel lock up if you pull the handbrake on, its called a handbrake turn. You just pull into the driveway front first at about 40 kph, then pull the hand brake on with a little lock, the rear brakes lock up and the car automatically reverse parks neatly into the garage. I guess at the point where you are almost rear bumper against the back of the garage you do regain some steering.
I borrowed my father's Commer van when I was an enthusiastic 20 odd year old. One of those Commer vans with the narrow front track and the wheels hidden up under the bodywork.
They were quite a surprise to drive, with the same 1725cc alloy head engine as the Hillmans, 70 mph cruising was a breeze.
Anyhoo we lived on a dirt road in Victoria at the time and I flicked the steering wheel and went to do a handbrake slide off the dirt road and into our farm's dirt driveway, f#cking near rolled it.
That was the day I learned Commer 2500 vans had a very efficient handbrake......on the front wheels.
Cannot agree more. One of two silly engineering things on the R8/R10/Caravelle. (the other one is engine and gearbox mountings).
If I can remember correctly, the bias of the front/back on the standard calipers is about 1.4:1. That is without a limiter.
I have 2 master cylinders on the race car with a balancing bar. I have increased the rear brake pressures so that the bias is now about 1.2:1 and I still haven't got lock-up issues, even in the wet. I think there is some relationship between the huge weight at the back and the lightness at the front, however not taking the weight transfer under braking into consideration. How did I calculate that figure? I did it on the temperature difference between the front and back rotors. Couldn't think of another way to do it in the backyard engineering shop.
I wonder what the break balance ratio will be on the 911 Porsches in standard form and then the ones racing in the Cup Series. That could surely explain a few things.
Regards, Frans.
If I can remember correctly, the bias of the front/back on the standard calipers is about 1.4:1. That is without a limiter.
I have 2 master cylinders on the race car with a balancing bar. I have increased the rear brake pressures so that the bias is now about 1.2:1 and I still haven't got lock-up issues, even in the wet. I think there is some relationship between the huge weight at the back and the lightness at the front, however not taking the weight transfer under braking into consideration. How did I calculate that figure? I did it on the temperature difference between the front and back rotors. Couldn't think of another way to do it in the backyard engineering shop.
I wonder what the break balance ratio will be on the 911 Porsches in standard form and then the ones racing in the Cup Series. That could surely explain a few things.
Regards, Frans.