kingr
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| posted on 31/1/03 at 12:18 PM |
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Hydraulic Handbrake
Given that the hand brake arms on the rear brake calipers arms that I have got have seized, and fixing them looks to be a bit of a nightmare, and
buying replacements is expensive, is it possible/SVA legal to use a hydraulic handbrake instead? I see they've got a hydraulic handbrake conversion
in the latest rally design catalogue which would be pretty cool.
Kingr
[Edited on 31/1/03 by kingr]
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johnston
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| posted on 31/1/03 at 12:30 PM |
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No it wont even get you an mot You must have a secondary braking system which is totally independant
if you burst a pipe with a hydralic hanbraking system you lose your hand brake as well as foot pedal
thats why people are starting to have trouble with rally cars they've paid 80k for
silly buggers
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JohnFol
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| posted on 31/1/03 at 03:06 PM |
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Johnston, just to confirm, it's not the fact it's hydraulic, it's the fact it shares the same pipework / reservoir or pistons.
For example if I had a brake cylinder attached to my hand brake leaver, as long as it had independant reservoir, pipework and actuator (caliper /
whatever) it would be allowed.
Is this right?
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johnston
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| posted on 31/1/03 at 03:18 PM |
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yeah sorry my mistake i was just thinkin if you were just runnin a conventional set up
i e drums or 1 caliper per wheel
BUT!!!! you could run hydraulic to bac and use citreon calipers on front for h/brake (bx i think)
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Fifer
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| posted on 31/1/03 at 03:39 PM |
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Thought it had to be a mechanical device ?
You can get duel system with hydraulic and cable combinations to do those lock ups at 80mph (for the 80K Rally Car, silly, lucky, buggers)
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Liam
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| posted on 31/1/03 at 07:35 PM |
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quote:
Originally posted by Fifer
Thought it had to be a mechanical device ?
If those are the official rules, then I suspect, like a lot of silly SVA/MOT rules it will be down to your tester's interpretation. I would argue a
hydraulic system is a mechanical device - cos it's not an electrical device.
Liam
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jollygreengiant
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| posted on 31/1/03 at 07:38 PM |
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The trouble is that with the hand brake levers being seized the the pistons will stick and that will give you other problems. Go to your local factors
and announce your self as a trader or mechanic, visiting, and ask for lots of trade discount (really haggle it) and I think that you will find that
echange recon calipers aint that dear for piece of mind. As for Citreon calipers with hand brake on the front (BX, Xantia and likes of) you can't
because you would need to run them on a seperate hydraulic system to the rear brakes, unless you used the rear as well from the same Citreon, because
the seals in the calipers are not compatible with normal DOT4 type brake fluid, it makes them fall apart in very short order.
Enjoy.
[Edited on 31/1/03 by jollygreengiant]
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stephen_gusterson
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| posted on 31/1/03 at 08:52 PM |
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i am reasonably sure sva manual says it must be mechanical.
an xj-s has a single disk brake mounted inboard of the rear axle as a handbrake. but its cable operated....
atb
steve
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philgregson
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| posted on 31/1/03 at 09:48 PM |
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My understanding is that the primary handbrake my not be hydraulic to pass an MOT. A hydraulic handbrake must be suplimented by a cable handbrake.
People used to dangle non functional cables and allsorts under rally cars to try and fool examiners - it used to work in the old days but they tend to
look harder these days.
People also knew examiners that would let them through with a hydraulic hand brake (and probably still do) but officially it must be a 'mechanical'
not hydraulic linkage - the theory being that the system could develop a leak whilst it is parked and your car disapear down a hill.
Personally I would sooner my handbrake failed whilst I was elsewhere than my main braking system went whilst I was driving - twin circuit I guess.
Phil.
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Rorty
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| posted on 1/2/03 at 12:27 AM |
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What about laser cutting/machining a small disc, which could be bolted onto the diff input flange, then use a go kart cable operated caliper. Super
light, and would meet MOT/SVA requirements.
Light weight hydraulic calipers could then be used at the wheels.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Viper
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| posted on 1/2/03 at 07:56 PM |
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quote:
Originally posted by Rorty
What about laser cutting/machining a small disc, which could be bolted onto the diff input flange, then use a go kart cable operated caliper. Super
light, and would meet MOT/SVA requirements.
Light weight hydraulic calipers could then be used at the wheels.
i believe landrovers used to use a handbrake on the propshaft...
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johnston
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| posted on 1/2/03 at 08:04 PM |
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quote:
the theory being that the system could develop a leak whilst it is parked and your car disapear down a hill.
i think the actuall technical term for the hand brake is an emergancy brake not a parking brake
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stephen_gusterson
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| posted on 1/2/03 at 10:24 PM |
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quote:
Originally posted by johnston
quote:
the theory being that the system could develop a leak whilst it is parked and your car disapear down a hill.
i think the actuall technical term for the hand brake is an emergancy brake not a parking brake
i think thats what the yanks call em - ever tried using one as an emergency device? better off stiking yer foot out the door - or using considerably
as an anchor 
atb
steve
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jollygreengiant
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| posted on 1/2/03 at 11:56 PM |
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quote:
Originally posted by Viper
i believe landrovers used to use a handbrake on the propshaft...
Yep & its called a transmision brake. Apply it at over 30mph in a land rover/range rover/discovery, and you could soon find yourself pole-vaulting
over your prop-shaft.
Enjoy.
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johnston
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| posted on 3/2/03 at 11:41 AM |
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had a few lessons in a mk2 at the rally school i mechanic at at wkends it gets called a turning aid there
 lots of fun especially in the snow this morn
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Wadders
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| posted on 4/2/03 at 06:52 PM |
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My understanding is that the primary handbrake my not be hydraulic to pass an MOT. A hydraulic handbrake must be suplimented by a cable handbrake.
How does the handbrake work on the latest 7 series beemers, they only have a switch on the dash, i guess they must be hydraulic, or does it somehow
lock up the transmission. i'm keen to get to the bottom of this debate cos iv'e just spent ages fitting a pair of small independent hydraulic
calipers to my car, thinking it would be ok for SVA/MOT.
Cheers
Al
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