goodall
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| posted on 17/5/07 at 01:32 PM |
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Handbrake
i have one handbrake caliper and i was thinking could i fit a disk to the fron tof my diff and use this as the handbrake rather than having to find
another caliper. would this be sva compliant ?
i would be able to use a very small disk as the diff ratio would amplify the braking of it. i would still be using standard calipers at each wheel for
normal braking and a hydrolic handbrake
[Edited on 17/5/07 by goodall]
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flak monkey
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| posted on 17/5/07 at 01:34 PM |
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Hydraulic handbrake is a no-no. SVA and MOT fail i am afraid.
Sera
http://www.motosera.com
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goodall
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| posted on 17/5/07 at 01:38 PM |
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but there would be a rear caliper (the kind that has a cable operation input) used on the input to the diff, it would be non hydraulic...
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blakep82
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| posted on 17/5/07 at 01:45 PM |
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this kind of thing could be used i guess
http://www.rallydesign.co.uk/catalog/product_info.php?products_id=8312
cable operated.
if you search the internet for 'prop shaft handbrake' theres a few people who do these in america. I was planning on doing it this way too
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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Hammerhead
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| posted on 17/5/07 at 01:45 PM |
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i've got a couple of spare calipers...what type do you need?
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02GF74
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| posted on 17/5/07 at 02:08 PM |
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this is a sound idea. there is a conversion made by X-eng (beware of orange painted copy) for land rover using cable operate caliper.
see http://www.x-eng.co.uk/X-Brake.asp?MID=31
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RichieC
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| posted on 17/5/07 at 02:21 PM |
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quote:
Originally posted by flak monkey
Hydraulic handbrake is a no-no. SVA and MOT fail i am afraid.
Just to clarify, thats a purely hydraulic handbrake, nowt to stop you using one which has a cable backup.
Rich
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goodall
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| posted on 17/5/07 at 03:29 PM |
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ok i havent really said this all that clearly maybe there would be two separate braking systems.
1. the handbrake would operate on the input shaft of the diff to a small disc and there would be the caliper of a audi 100 rear axle used to do this
braking to hold the car in place when its parkd
2. there would also be a the pedal braking which is a normal system with a caliper at each hub, these calipers would however would also be connected
hydraulically so that if say i wantd to do a handbrake turn i would have to lock the wheels up through the diff "as that would cause a huge
stress on the diff)
when i said i had one handbrake caliper i meant it was mechanical type of one
hammerhead are those the type of caliper witht he cable input (ie handbrake type ones) if so id be very interested if they are for a reasonable
price
simply my question is, can you have brakes that work on the diff input shaft that are mechanically actuated that will full fill the required
handbrakeing to pass the sva.
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DorsetStrider
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| posted on 17/5/07 at 04:56 PM |
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Correct me if I'm wrong but my interpretation of the SVA manual is slightly different.
It says that there must be two entirely seperate braking systems... but it doesn't say they can't BOTH be hydrolik...... or am I being a
dunce and missing something here?
Who the f**K tightened this up!
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flak monkey
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| posted on 17/5/07 at 05:01 PM |
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Thanks Mark, wasnt just me going insane then 
http://www.motuk.co.uk/manual_310.htm
quote:
Hydraulic parking brakes as a sole means of operation are not acceptable on vehicles first used on or after 1 January 1968. However, they may be used
to assist the application or release of a mechanical brake.
Operating on the input shaft also wouldnt stop the wheels turning. Granted they couldnt both turn forward, but they will turn in opposite directions.
Sera
http://www.motosera.com
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Bob C
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| posted on 17/5/07 at 06:00 PM |
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Seems clear enough to me (probably because I worked along the same lines)
On the rear wheels I have 2 hydraulic only calipers (wilwood single floaters - REALLY light weight)
On the propshaft I have a wilwood "mechanical spot caliper" connected to my handbrake lever.
The combination met all criteria and passed all SVA tests.
Old landrovers had "transmission " handbrakes - famously rubbish!
I must say the one on my car works incredibly well as a parking brake - I've never tried to use it at speed, there are a number of worries with
this including a rubber doughnut and an ATB diff between the brake disk and the wheels......
cheers
Bob
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mark chandler
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| posted on 17/5/07 at 07:18 PM |
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Landrover prop brakes work very well when correctly adjusted, to the degree that dragging them on before halting had a nasty habit of breaking prop
shafts.
The down side to them is that both wheels have to be on the ground for them to work, so on a slippery surface when one wheel breaks traction the car
moves.
[Edited on 17/5/07 by mark chandler]
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goodall
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| posted on 17/5/07 at 10:14 PM |
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ah so it will be sva compliant, thanks. so wont need to buy any calipers then 
yea i wouldent want to pull the prop brake at too high of speed as it could strip the diff gears for all that if you had no other brakes it would be
the time to try! 
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britishtrident
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| posted on 18/5/07 at 06:47 AM |
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Although they are useful in true off road vehicles Transmision brakes are really nasty things -- major manufacturers abandoned them for road use in
the 1920s, avoid at all costs.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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NS Dev
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| posted on 18/5/07 at 12:05 PM |
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quote:
Originally posted by goodall
i would be able to use a very small disk as the diff ratio would amplify the braking of it.
[Edited on 17/5/07 by goodall]
errr will it??????????????????
Think about it!!!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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flak monkey
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| posted on 18/5/07 at 12:22 PM |
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Effectively you have the wheels trying to drive the input shaft of the diff, so large crown wheel trying to turn small input pinion, so the ratio is
geared up. So torque to the ouput pinion is reduced from the torque at the wheels.
Its working the opposite way to normal isn't it? Normally you have the small pinion driving the crown wheel which increases the torque at the
wheels.
Not correct? Miss something? This may of course just be the insane ramblings of a liquified brain due to too much revision.
[Edited on 18/5/07 by flak monkey]
Sera
http://www.motosera.com
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Bob C
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| posted on 18/5/07 at 12:26 PM |
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Yeah Nat, if the diff is 4:1 then the prop will do 4 turns for 1 of the wheels. So the rotating speed of the wheels is 1/4 the prop and the torque at
the wheels is 4x that at the prop.
So even if tou reckon there's just 1 brake instead of 2 you're still x2 in braking torque; - but you get that back because you're
squeezing just 1 caliper instead of 2 (each of which normally gets 1/2 the pull of the handbrake)
ttfn
Bob
PS when I were a lad.... we had a series2 landie then a series3. The handbrakes were pants
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