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Pete Boy

Volvo c303 disc brakes?

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Are they suzuki sj discs and passat calipers?????

Good luck stopping! especially if your running decent sized tyres

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Have you driven a drum braked c303? ;)

Yes would have preferred a larger/vented disc, but finding a solution at all is not easy.

Its going to be better than the drums.

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I haven't driven a drum braked 303, but I'd wager in good order they are capable of a greater braking effort than is possible with those discs and calipers.

Even if you can generate enough clamping effort with those discs to give a decent braking force, the heat buildup will be massive leading to rapid brake fade and probably warping the discs.

I would just be making my own conversion to use tlc80 stuff up front and something else 6 stud and suitable on the back with rangerover calipers, at least then the gvw's of the donor and the recipient are close.

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Hmm, I suspect you are right. Although i think the stopping power may be ok, the heat build-up could be a problem. I had enough of that on my 110 to covert to vented.

So that kind of brings me back to Mcs Juniors friend and his solution. Landrover discs & calipers.

NewPortals015_zps5402b2b7.jpg

NewPortals005_zps100207ae.jpg

Or something DIY with TIG'd hubs e.g

P4250021_zps982a41c0.jpg

Which brings me to another question - how much tinkering with the hubs/brakes can one do and remain road legal?

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Out of curiosity does anybody have any brake test information for a properly set up drum brake compared to a disc brake conversion?

Or even something like the 109V8 against the early 110 V8 for example?
Discs have pro's but also cons. In really abrasive environments like opencast coal a drum brake will last literally ten times the time a disc will.

A drum brake like that fitted to the Volvo axle as standard will resist heat a lot longer compared to that tiny disc in the Polish conversion. Heat build up is not a myth. I'm sure that brake could be put together with 4 pot callipers and made to work nicely for a while but it's tiny and all the heat soak will be into your portal housing and bearings which make enough heat as it is.

If you look at the brakes fitted to small commercial vehicles with a 3.5 ton GVW you will also see they are significantly more substantial than the conversions posted thus far. The C304 or 306 have a 4.5 ton GVW and the drums work fine on them. I'd have thought on a Land Rover that's less than half the weight of that would experience little problems?

Has anybody looked at the master cylinder and boosters on a Volvo? How do they compare to a Land Rover?

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Yup good advice guys, i was looking at the wood & could not see the trees..

What do we think of the road legality of the LR based conversion above?

On a C30x The master cylinder is similar to the LR version, except dual independent circuits. There are 2 boosters one for each circuit, IIRC they are identical to LR ones.

FYI (diagram is for a 306, on the 303 the red/blue circuits go to one rear wheel each.

TGB13_Brakes_principle_zpsa65ce9bd.jpg

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Double the number of servos, and from memory the manual says it engages all the difflocks if you anchor on hard :blink: not sure if that's a safety feature or what.

I doubt very much any of the disc conversions would count as road legal. The ones that machine down std hubs make me a bit nervous, the one that welds a load of stuff back on makes me VERY nervous.

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and from memory the manual says it engages all the difflocks if you anchor on hard :blink: not sure if that's a safety feature or what.

It does indeed. I agree seems more like a blow-the-difflock feature to me.

But we must have folks here driving around on modifications like this? Wheres our resident MOT testers?

If i'm being devils advocate (not the yellow sticky one) the Portaltek system is not original, who's to say that is legal?

It's clear that the LR based conversion above is the stoppiest and the best constructed. Yes hubs are machined down, but with a gazillon bolts.

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MOT testers don't determine vehicle legality I'm afraid.

At the end of the day if a modification to your vehicle causes an accident questions will be asked and if you follow recent cases you will find they will throw the book at you, brake or anything else.

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Hitting the brakes hard only activates the front drive selector, not the difflocks. It stops the back wheels locking up due to the weight transfer due to the high c of g in the Volvos. Also very handy if you run a 6x6 as a chassis cab.

In all fairness, a Land Rover putting the same pressure to the wheel cylinders as a Volvo would lock the wheels very easily in any circumstance. Worst case I heard of was someone used Land Rover wheel cylinders in his Mog axles and wondered why it wouldn't stop.

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C30x don't have a centre diff, they are rear wheel drive and a conventional dog clutch arrangement operated by a vacuum. The Vacuum is controlled by a solenoid. 4x4 (6x6) selection is by a push button switch on the dash. Heavy braking also activates it by the same means. They require a vacuum to disengage the drive to the front axle and an electrical signal so a failure in either will result in the front axle engaging. Switching off the ignition for example will engage the front axle.

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Ok, well you know what i meant - I'll rephrase it 'the centre 4wd lock'

Anyway putting this back on topic, its about disc conversions.

I've been putting a lot of thought into whats sensible/legal if i want to drive the disc converted vehicle on the road.

If the MOT testers are not required to judge that, then one has to consider ones own safety and potential consequences in the event that an accident occurred.

Now I suppose that if a standard manufacturers part fails and causes an accident, It would go one of two ways - Did the part fail (take action against the manufacturer) or was the part fitted incorrectly (take action against the fitter).

Now if someone makes a non-standard modification, it would be sensible to make some sound engineering documentation to back it up.

But just what is enough?

One can calculate that the stopping force of the solution is the same or better than original and suitable for the GVW. That secondary effects such as heat have been accounted for, And that the solution is strong enough for the use.

I would really appreciate some input by the real engineers here, who could give some advice.

(I'm sure that this isnt the first time this subject has come up)

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You can get your finished an Individual Vehicle Approval, which would make it legal. Several firms offer sva and Iva engineers statements.

With regard to braking systems, if you have a passenger vehicle it will be required to pass M1 type approval, if I remember correctly commercial vehicles have a less stringent N1 test

http://www.vca.gov.uk/vca//vehicletype/individual-vehicle-approval.asp

To my knowledge this facility exists only for new vehicles. If your vehicle is made partly or wholely of used parts then I would imagine an sva test is your only route to legality.

Most of the M1 brake tests can be replicated without specialist equipment so you would be able to get a good idea of whether your braking system is adequate prior to the test. Perhaps someone with first hand experience of the sva could shed some light on the braking component of the test

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Type approval means it going on 'Q' plates? and i suppose special insurance rates?

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Now I suppose that if a standard manufacturers part fails and causes an accident, It would go one of two ways - Did the part fail (take action against the manufacturer) or was the part fitted incorrectly (take action against the fitter).

Now if someone makes a non-standard modification, it would be sensible to make some sound engineering documentation to back it up.

But just what is enough?

One can calculate that the stopping force of the solution is the same or better than original and suitable for the GVW. That secondary effects such as heat have been accounted for, And that the solution is strong enough for the use.

I would really appreciate some input by the real engineers here, who could give some advice.

(I'm sure that this isnt the first time this subject has come up)

I don't think either of the manufacturers parts would "fail" in an accident,

I think that if the lack of braking effort was the primary cause of the accident, then you would be the one the action would be taken against because you have selected the undersized inadequate components, this would be your responsibly regardless of who manufactured or fitted them.

I'm sure there is a complex mathematical equation to work out and compare braking efforts,

But I simply size components by the gvw of the donor and recipient as well as pad size and piston size.

As an example the standard front brakes on my GQ patrol were poor at best. they were single pot sliding calipers @ 68mm diameter with 142x52mm pads clamping 295x20mm discs.

The disadvantages of this setup are that the single piston cannot equally distribute the clamping effort to the pads, and the discs aren't as big a diameter as there is space in the wheel for and they are not thick enough to dissipate heat well to resist fade.

I chose to upgrade to nissan 200sx 4 pot calipers 4x40mm pistons with 120x70mm pads, clamping early tlc80 311x32mm discs.

so i now have calipers able to equally distribute clamping effort to slightly shorter but taller pads gripping a much larger thicker disc that increases effort and resists heat buildup and fade

The result is i have much more effective brakes, i can lock my wheels at nearly any speed now and i have not experienced any brake fade, but i do have a mismatch on master cylinder size because of the much greater area of the 4 pot calipers this mainly seems to be affecting brake pedal feel, but little else.

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Type approval means it going on 'Q' plates? and i suppose special insurance rates?

It may do, so your options are

Don't get the vehicle approved, risk it on the road, and hold insurance for no purpose (as it will be useless in a claim)

Or

Get the vehicle approved, fit a q plate if they dictate you need one, pay lots more for your insurance but actually be covered and legal in the event if a claim

OT: dirtydiesel, do the 200sx (s14) calipers bolt straight on to the patrol hubs? Lots of Nissan stuff is common like that - I fitted a full Z32 300zx setup to my old 200sx s13, the front calipers are similar to the ones you are using but are all aluminium. And likewise I retained the OE master cyl, the pedal travel was increased but it didn't bother me

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OT: dirtydiesel, do the 200sx (s14) calipers bolt straight on to the patrol hubs? Lots of Nissan stuff is common like that - I fitted a full Z32 300zx setup to my old 200sx s13, the front calipers are similar to the ones you are using but are all aluminium. And likewise I retained the OE master cyl, the pedal travel was increased but it didn't bother me

You know me all my conversions "bolt on" :ph34r:

DSC_0579_zps0b692e6d.jpg

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I used to hang around with some guy who regularly said that to every problem there is a welding solution.

I did look but I can't find the quote

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IVA isn't type approval, its Individual Vehicle Approval. Type approval is a whole different ball game manufacturers go through to get a 'type' of vehicle approved ready for mass production.

If you asked for an IVA for a brake conversion I'm not sure VOSA/DVLA would know what to do about it.

Basically it is on your head.

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In no way did I mean to imply that type approval and Iva are one and the same. I merely mention the M1 and N1 type approval tests as useful benchmarks for safe braking systems. Apologies if that was not clear in my above post.

The vosa facilities which are able to perform Iva and sva are being reduced, the staff at the remaining locations seem to be more competent and better trained. The reduction in testing stations for Iva has led, in part, to us seeking type approval from vca rather than Iva every vehicle we build. Other firms like Optare are continuing with Iva

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All they do on the SVA (now IVA), is to check on a 4 poster bridge if all 4 calipers work if you press the brakepedal. Then they take it on a flat bit of track and stand on the brake pedal. If the front wheels lock up before the rears, its a pass. No other tests or calculations are required. Whether you would want to subject your car to an IVA test after changing the brake setup, is up to everyone to decide, but I suspect it is the only way to be legal. I dont think an IVA test automaticaly means a Q plate. From what I gather, this is only if your car is a bitsa, made up out of used parts.

I think (someone might correct me) if you subject your existing car to an IVA in order to approve the brakes, your reg should stay the same.

Daan

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I spoke to VOSA at length about my stage one with no relevant original parts at all left on it. They could test it no problem but they were unable to tell me anything about the registration number as that was for the DVLA to decide. I was concerned partly about sorning a vehicle every year that had morphed into something else. By getting issued a new registration number then what happens to the old one as there's no vehicle getting scrapped and no place on the new V5's to scrap it anyway. VOSA also said in their experience it would 'probably' keep it's original number.

This was all at a visit to VOSA so when it ever comes to the bit I've no record of my previous communications with them and I'll start from scratch. My mistake but I'd suggest do all your communication by e-mail and have a record then.

I'd be confident you're not going to make anything unfit for purpose but as it's for a Volvo you might actually approach them and get something in writing directly. Recently a German lad got a letter from Volvo to satisfy the German TUV that his 4.2 Toyota conversion was safe.

https://www.youtube.com/watch?v=ZmmJkgRLqvQ&feature=player_embedded

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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?

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Out of curiosity does anybody have any brake test information for a properly set up drum brake compared to a disc brake conversion?

Or even something like the 109V8 against the early 110 V8 for example?

Discs have pro's but also cons. In really abrasive environments like opencast coal a drum brake will last literally ten times the time a disc will.

A drum brake like that fitted to the Volvo axle as standard will resist heat a lot longer compared to that tiny disc in the Polish conversion. Heat build up is not a myth. I'm sure that brake could be put together with 4 pot callipers and made to work nicely for a while but it's tiny and all the heat soak will be into your portal housing and bearings which make enough heat as it is.

If you look at the brakes fitted to small commercial vehicles with a 3.5 ton GVW you will also see they are significantly more substantial than the conversions posted thus far. The C304 or 306 have a 4.5 ton GVW and the drums work fine on them. I'd have thought on a Land Rover that's less than half the weight of that would experience little problems?

Has anybody looked at the master cylinder and boosters on a Volvo? How do they compare to a Land Rover?

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

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