Hydraulic Handbrakes

[rustybin]

Does anybody have experience of getting a car through SVA with only a hydraulic handbrake, in particular, one that acts on the same callipers as the service brake? The SVA regs seem a bit unclear.

[traction]

If they look at it in the same way scrutineers do for rallying, they expect it to be plumbed in as a separate system i.e. there isn't one point of failure that means all braking is lost.

Your best bet is to phone your local SVA station to check anyway.

Ta.

[egomeister]

As far as I know, it is a requirement for a car to have a mechanical handbrake in the uk - although this doesn't mean a hydraulic one can't be fitted aswell.

[Mapper]

Hi all
Hydraulic handbrakes are a definate no-no in sva, "the handbrake has to be maintained in the on position by purely mechanical means". Hope this helps
Mapper

[Purple AK]

For SVA and MOT a handbrake is deemed to be a secondary braking system for use in the event of a failure of the footbrake. As such it must be totally separate system, with the exception of the shoes/pads that it operates! So definately a No No
Cheers

>> Edited by Purple AK on Tuesday 29th June 20:19

[Avocet]

I think you can probably have a cable AND a hydraulic system so long as the cable system is doing the work at the time of the SVA test. After that, the cables might go slack...

[Funderbunk]

Interestingly, on the 115 series Alfa spiders, the handbrake is a completely independent system - the only shared component is the rear brake rotor/drum combo. Once when asked if it had rear discs or drums, I rather enjoyed answering, "both".

[Mikey G]

It strikes me strange that we have to have 'mechanical means' to hold the car in a stopped position yet we have to rely on hydraulic means to stop the thing at 70mph

[rustybin]

There definitely seems to be a concensus here. I am not entirely surprised. My hope was to be able to use the front suspension of an Alfa 33 at the back of the car (and the front) but this does not have a handbrake (thus the question)any bright ideas as to how to overcome this much appreciated.

[grahambell]

Aparently some Land Rover models (Range or Disco I think) have a handbrake that works with a small disc fitted to the propshaft. Maybe you could adapt a couple of the mechanisms from that to fit the rear discs.

[rustybin]

Found some landy stuff on the Interweb. Apparently other than the freelander they all have a transmission hanbrake. Unfrotunately it is a drum type unit with the back plate, shoes etc mounted on the back of the gearbox and a dirty great drum on the propshaft. I think it may be impractical to convert this for my needs. Hs got me thinking though so thanks for the reply.

[Dave^]

if you are thinking of using a transmission handbreak, DON'T (imo anyway). if you do need it for stopping, it with either, not work very well, or, will knacker up you running gear if you use it to stop from anything about 1mph.....

[williamball]

Wilwood do a small mechanical caliper www.wilwood.com/products/calipers/msc/ OK you'd need to make up brackets and there'd be 2 calipers on the disk (the original for the service brake, and the mechanical one for the handbrake), but a reasonable option maybe.

WB

[grahambell]

Of course the other option is to have a look at cars with rear disc brakes to try and find some calipers with fitted handbrake mechanism that will fit your Alfa discs. Later Alfas perhaps?

A good look round local scrappies armed with a tape rule might bear fruit.

[Purple AK]

rustybin said:

There definitely seems to be a concensus here. I am not entirely surprised. My hope was to be able to use the front suspension of an Alfa 33 at the back of the car (and the front) but this does not have a handbrake (thus the question)any bright ideas as to how to overcome this much appreciated.

The predecessor to the 33 the Sud, had a mechanical handbrake working on the front inboard discs, notoriously crap after more than 10 aplications but may be an answer to your problem.
Cheers

[davefiddes]

williamball said:

Wilwood do a small mechanical caliper

That's how Ultima's do their handbrakes. The caliper is a Brembo unit (that AP resell with their brake kit).

Funderbunk said:

Interestingly, on the 115 series Alfa spiders, the handbrake is a completely independent system - the only shared component is the rear brake rotor/drum combo. Once when asked if it had rear discs or drums, I rather enjoyed answering, "both".

Volvo 850s are like this too. If you can stand the weight and complexity the additional drum brake should make a better handbrake.

[Avocet]

I have an Alfa 164 which has a rear disc setup with the handbrake working the rear calliper pistons. It's a very common setup. I think some Sierras / Granadas had them too. Its quite a small calliper - single piston sliding type. The handbrake lever just ratchets up a pushrod inside the piston so that it it mechancially pressed against the disc. The footbrake still actuates it hydraulically.

I accept the argument that a hydraulic brake can stop the vehicle from 70MPH but it rarely has to hold it stationary on a hill for a week or two!

[kenmorton]

2.0l Mondeo has rear vented disks with mechanical handbrake mech built into the caliper. Should be loads of them in the scrapies, just need suitable bracket fabricated.

[rustybin]

Loads of great responses and ideas to follow up. Thanks guys. I'll let you know how I get on.