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Pete Boy

Volvo c303 disc brakes?

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Thanks for the video :blink:

I'm just wondering what those folk here who have portal axles under their LRs did?

I ran G wagon 460 front discs and calipers on unimog 404s, they are a 4x44mm calipers and 303x16mm solid discs. No problems stopping at all.

Not on portals, but i MOT'd my truck with a fully adjusted brand new set of full drums and decent shoes, then a couple of weeks later did my disk brake conversion on my series axle. (standard 10" drums all round to 10" drums on the rear and discovery single line disk brake system on the front)

my disks and pads werent bedded in by the time i had its stopping performance measured, which would have affected the efficiency, but surprisingly although i cant remember the exact figures, the drum system was 10% more efficient than the disk system

On my patrol the brake efficiencies went up from under 400kg each with no lock outs to maxing my (ancient) RBT out at 650kg each both locked

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out of interest (and i assume thats drums (under 400) to disks (over 650)) were the drums fully adjusted and balanced?

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The drums worked reasonably well when they were adjusted. But it was a constant effort. I would find after a few weeks that one or more would be dragging, or not braking well. The problem is that they are quite corroded inside, so i would have to completely renovate, new shoes, possibly cylinders, springs and other bits. And then i might get a usable solution, but i would rather switch to discs and save all of that hassle.

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Mikey, that was discs but pathetic calipers to decent calipers, Dan posted about it earlier in thread.

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The drums worked reasonably well when they were adjusted. But it was a constant effort. I would find after a few weeks that one or more would be dragging, or not braking well. The problem is that they are quite corroded inside, so i would have to completely renovate, new shoes, possibly cylinders, springs and other bits. And then i might get a usable solution, but i would rather switch to discs and save all of that hassle.

exactly why i changed to front disks, i actively argue that drums CAN be just as good as disks, if not sometimes better. but it does depend on so many variables like which master cylinder, wether its suited to the "actuator" in the system.

but of course the downfalls of drums are fade, and most of all, the wear. when heavily towing over the moors even when using engine braking to the max, i could get through a full set of front shoes in a day. not ideal!

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Mikey, that was discs but pathetic calipers to decent calipers, Dan posted about it earlier in thread.

ahh cheers sorry should really take the time to catch up on missed posts :)

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exactly why i changed to front disks, i actively argue that drums CAN be just as good as disks, if not sometimes better. but it does depend on so many variables like which master cylinder, wether its suited to the "actuator" in the system.

but of course the downfalls of drums are fade, and most of all, the wear. when heavily towing over the moors even when using engine braking to the max, i could get through a full set of front shoes in a day. not ideal!

Wear...?

I completely disagree and so does every single commercial operator on the planet who's running disc brakes on his trucks now.

It's well known that discs of a similar stopping power to drums dissipate heat faster and have less fade and if fade is a problem then a good reason to swap to discs but also it's well known and any Google search or asking large users that pads wear a lot faster than shoes. Especially in mud or abrasive ground conditions. An exception might be if said shoes came in a blue box?

Examples 1 Opencast coal mine, Unimog 404 fitters vehicle with drums, never ever changed shoes as long as I was there, one stint was three years. Unimog U1300 fitters vehicle with discs, changed at least every year. Defenders in the same place were changed nearly every month.

Example 2 Land rover defender fleet in Angola, rainy season driving, Every month, Actual kilometres driven would be around 500. There were also half a dozen 109 Ambulances used as backup vehicles and in my three years in Angola we never changed the shoes once.

Example 3 Toyota fleet in Afghanistan of around a hundred 'cruisers and 20 hiluxes was 400 sets of pads and 20 sets of shoes for the last year.

Example 4 My C304. I've put 11,000 Km's on it as my daily driver and the shoes are about the same as I picked it up in Dover with 3,000Km's on the clock.

Something is really wrong if the shoes wore out in a day.

I wouldn't for a minute suggest drums are better than discs for a competition style 4x4 vehicle but to change from drums to discs on a 4x4 because of wear is potentially quite misleading to novices who might be reading this. Lets stick to the facts.

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fair enough then,

from my experience anyway the front shoes didnt last long at all, the "wear out in a day" thing is very extreme, and its not often that this happens to anyone. im not saying you are wrong and i am right, to be honest it more than likely was down to the friction material quality, (I NEVER use b**tpart though for obvious reasons especially on brakes)

i have only ever once changed a rear set of shoes over 4 years, and i dont neglect them. but the fronts did seem to seriously wear. i dont have that problem now, i have gone for a year with my current greenstuff pads which are still 75+% material left (which btw i wouldnt actually reccomend despite the reputation being wuite good, they give a spongy pedal and do wear faster than Mintex which i normally use)

i also found that getting mud in the brake drums rapidly accellerated shoe wear, as it couldnt escape as easily.

but again, this is just my experience on my truck. i have never once replaced the shoes on our MF 135 which lives in muck as its a scraper tractor. and theyres still probably 50% plus material on there. (its been at least 10 years since they were last changed) which would support what you say too. i dont want to go about misleading poeple at all.

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The wearing out problem of drums does mainly occur when used in mud; On my series, if i did an offroad event that was a long way away, I would take of the front drums and clean it out before I drove home. If not, the shoes would be gone by the time you get home. Also, they would never brake straight when any mud had gone in there, not to mention marginal brake power. With disks, it only needs 1 rotation and the mud falls of the caliper and the brakes work. It all depends on the conditions basically. If you only drive it on the road, the drums work fine.

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A friend of mine has made a disc conversion to his Volvo axles that retains the 8 stud wheel fixings and does not increase the track width, but does require shallow well 16" rims to clear the Wildwood calipers. In Australia we are not legally permitted to widen the wheel track by more than 25mm each side .

My experience with LWB drum brakes requiring constant adjustment is due to the snail cam adjusters backing off. I have only replaced the brake shoes on WildFing once in 12 years, but I always use the brakes sparingly, mainly using the gearbox for retardation except when requiring a full stop . As to brake fade, or more accurately in my case, efficiency when wet, I'm going to sacrifice a new set of brake shoes and drill them full of holes in an effort to break up the film of water/mud or gas(in the instance of heat fade) and see how that goes. Brake fade I've read is the lubrication of these elements, including gas that reduces friction. If they can be broken up or squeezed out, things should work betterer.

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My experience with LWB drum brakes requiring constant adjustment is due to the snail cam adjusters backing off. I have only replaced the brake shoes on WildFing once in 12 years

I'm the same, I replaced the brake shoes on my stage one (which has spent plenty of time bogged and stuck all over the place) when I rebuilt it in 1994. It had one set of shoes in it when I put the Santana axles on it a few years ago. I can't honestly say the brakes are really any better with discs. At least not worth the messing around with the different axles and converting it for the sake of discs. I used a 90 / 110 master cylinder. I should have put 80 series axles on it but that was before I learned KAM wouldn't / couldn't sell me the Santana Difflocks. The pedal's harder for sure and doesn't travel as far but I'd still say my only observation of the conversion is the drums were easier to lock the wheels when winching. The discs probably handle lying around in the wet grass where they live better than drums would have to be fair.

Not having to adjust the brakes is nice but if a twin leading shoe setup is pulling to the side then something's wrong somewhere. Wide shoes and drums are for sure more sensitive to wheel bearings being loose than discs are.

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For general daily use I found pulling to one side or the other was cured by fitting Stage One/110 oil catchers to the backing plates and riding the brakes for the first 50 metres each morning.

I have thought about fitting modified Toyota adjustable wheel cylinder pistons to the Rover cylinders to address the issue of the cams backing off.

My mate could never get his Volvo drum brakes working effectively despite all new everything and a twin diaphragm booster, yet I run the same size brake drums/shoes with no booster but with the original 1 1/4" rear w/cyls replaced with 1" and a smaller 15/16" single circuit M/cyl and deem it quite acceptable. I always keep the handbrake in good working order for those regular occasions when I rip a brake hose or line off in the bush Lol.

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Sounds interesting, but I have yet to see any conversion which machines down the Volvo stub that looks convincingly up to spec strength-wise compared to the original.

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Sounds interesting, but I have yet to see any conversion which machines down the Volvo stub that looks convincingly up to spec strength-wise compared to the original.

The Volvo Stub axle AFAIK wasn't machined down, just cleaned up and drilled for LandCruiser rotors, and one hole for an alan key socket to fit 6 socket head bolts to the Volvo stub axle bearing housing.He does have the conversion on CAD file. When he returns from the Simpson Desert in a couple of weeks I will ask if he is happy to make it freely available.

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Is this a road legal (engineered) conversion in Victoria? If so, I would be very intererested to find out more. Getting engineering approval is going to be a difficult process, but if one already exists, then things are much easier.

Would be great to get hold of the info.

Well no, the conversion hasn't been submitted for RTA engineering approval, but from what I have seen of it, I can't foresee any problems from an engineering viewpoint. My mate's truck is a RR/Jeep/Volvo Hybrid with other mods such as 40" tyres etc, that wouldn't be approved, so he didn't bother with approval for the brakes, although he did design them to be within the legal track width allowance.

Due to the Volvo portal box's design, with few flat/thick surfaces from which to mount the calipers close enough to the axle centre to clear a 16" rim,I don't see too many options for a legal conversion for us here in Australia. I built a Volvo axled 110 County and had it engineered in Melbourne on drum brakes after passing the braking and fade test, so IMO it's not the end of the world if one is forced to live with drums.

As far as brake drum replacement goes, LandRover 11"x3" brake drums can be bored out and re drilled to work on Volvos.All the other bits are LandRover anyway.

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I came across this post researching spares for my volvo portals.

I have converted mine to disc for a very reasonable cost compared to some of the kits available.

Here is a brief video description:

I used Toyota Hilux brake calipers and rotors (early 1981 - 1985 solid rotors), rebuilt calipers I had lying around and bought brand new rotors for a few hundred bucks. The laser cut brackets for all 4 ends were less than $50. The only expensive thing was getting the drive flanges machined down to fit the rotors and new stud holes drilled, I also had rings machined up to be welded on the back side of the drive flanges to give a flat surface for the wheel studs to seat on and add a bit of material back to the drive flange.

I am running 39" stickies and a Lexus V8, its stops just fine but this is an off-road only vehicle (buggy).

This was about 6 years ago, cant remeber the actual cost, but it wouldnt of been around $1000 AUD mark all up for 4 corners.

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Hi All,

Well due to a technical glitch, it looks like my previous posts have been lost from the system... :(

However - small progress report on the disc conversion. I have now managed to get the hub scanned and transfered into Catia (CAD) :i-m_so_happy: see attached pictures.

Scan worked out pretty well - with the dirty rusty hub coming out is amazing detail, but the shiny shaft less so. It is a 70Mb file otherwise I would have attached that here too for all to have access to.

Ian.

post-31208-0-27781700-1408569129_thumb.jpg

post-31208-0-92475000-1408569141_thumb.jpg

post-31208-0-64908100-1408569158_thumb.jpg

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how much did the scan cost, very interesting stuff!

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I suppose to improve the shiny-bit scan, you could just dust it with some matt paint from a rattle can?

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The scan was done at work as a training exercise on a new scanner, so other than patience, cost me nothing.

We knew the main hub element would scan ok due to the matt surface, and this for me is the main point of interest. The guys at work were keen to see how the new scanner handled the shiny spline as normally you can't scan reflective surfaces. The result was better than expected for a first attempt.

It may go back in again to see if they can improve the results, but depends on available time. For now I have what I need.

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What are you doing with it? Machining a new stub or making something that bolts to it?

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Plan is to machine down the current hub to accept the P38 discs and wheels (PCD 5 x 120mm)... Here in Australia (Victoria) I need to get this conversion signed-off by an "approved" engineer, and part of this is proving thet the changes will not effect the vehicle's performance.

Accurate CAD can be generated from the scan and then some basic CAE to prove (or disprove) similar strength. If the remachined hub doesn't meet the requirements, then I will investigate new machined hubs which can.

It's a long slow process...

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Out of interest, have you done any metallurgy on them? 'cos I can tell you they're definitely hardened.

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It looks like it has been a few years since this topic has been addressed here. Does anyone know if the C303 disc brake conversion has made progress. I've just picked up a 1977 C303 and would like to  convert to disc brakes

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