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Decent handbrake caliper for solid discs
itsawindupuk - 10/2/16 at 10:31 AM

Hiya guys. Anyone know of any good handbrake calipers for solid discs? I've looked at the wilwood ones and they mostly use vented. Could I use a spacer? Or are there other options? I'm happy to use a spot caliper but heard the wilwood one sucks but can't find any others with reviews. It's for my MGB which has 4 pot wilwoods on front and I'm doing a disc conversion at the rear.
Thanks


loggyboy - 10/2/16 at 10:42 AM

Why not just convert to an OE caliper with handbrake built in? Sierra & Golf are popular choices.


nick205 - 10/2/16 at 10:45 AM

VW Golf rear calipers seem popular and should be widely available.

I've just sold my Passat B6, which had an electric parking brake via a dash button - levers seem very out dated to me now


Neville Jones - 10/2/16 at 10:59 AM

Golf, Passat, Seat, Skoda, all VAG group.

If you want to get all technical and balance up the braking effort before using a balance bar, then these come in a few different piston sizes, to give differing force.

They are a bit lighter than the Sierras as well, being ali.

Cheers,
Nev.


itsawindupuk - 10/2/16 at 10:59 AM

Cheers for the replies guys. I thought about those and will probably end up with that kind of option but being a tart I kind of wanted something to aesthetically compliment the fronts lol. The electronic brake sounds interesting, I'm building a new wiring loom for the car so that could be integrated.


mcerd1 - 10/2/16 at 11:19 AM

HiSpec do a handbrake caliper as a direct replacement for sierra ones - but they aren't cheap (and I've not always heard good things about the customer service either...)


nick205 - 10/2/16 at 12:58 PM

I believe the Passat's EPB (Electronic Parking Brake) uses an electric motor to pull a cable to operate the brake - you can hear it when activating the brake.

Interestingly, the first Passat I had (57 plate) had this plus a button by the gear stick to activate "Auto-Hold" for hill starts. The second Passat I had (57 plate) didn't have this, but if you activated the EPB for hill hold it let you drive away and released the EPB by itself. Both approaches worked fine and the extra space in between the front seats due to the lack of lever was very welcome.

On my MK Indy I utilised the Sierra rear drum brakes with a cable operated hand brake. Since it was used infrequently and parked on flat ground I used to leave the hand brake off and chock the rear wheels. This saved the drums jamming on, which can be a PITA to release.


nick205 - 10/2/16 at 04:29 PM

Knowing VAG's like for cost saving and component sharing I suspect you can get the same rear calipers on a number of VAG vehicles. The one I've seen used are alloy and look OK too.


Sam_68 - 10/2/16 at 06:46 PM

quote:
Originally posted by nick205
I believe the Passat's EPB (Electronic Parking Brake) uses an electric motor to pull a cable to operate the brake - you can hear it when activating the brake.


HiSpec showed a caliper with a motor mounted on the caliper itself, to provide an electronic handbrake, at this year's Autopsports show. Still quite a light assembly, even with the motor (it's a sliding caliper, so just one piston and one set of pads serving for both hand and footbrake). They're just in the process of costing it for production, they said, but IIRC a figure of around £185 per caliper was anticipated.


Dingz - 10/2/16 at 07:28 PM

Use MGF ones, keep it in the family as it were.
I think I have an old set somewhere?


obfripper - 10/2/16 at 09:25 PM

The passat caliper has an integrated motor, it's not much heavier than an ordinary caliper, other models also have a cast iron version that is heavier.
The aluminium passat version does have one caveat, they slowly corrode, the pressure of which eventually cracks the plastic motor housing letting water into the motor/electrical connector followed by failure, this probably wouldn't be an issue with a kit kept in the dry.

It wouldn't be too hard to use in a kit application with some ic's, relays and auto resetting polyfuses, using basic operation knowledge.
Under normal operation, the control unit operates the motor in the apply direction to a preset current(iirc 20a per caliper) then cuts off, and in the release direction for a preset time period (iirc 2 seconds).
When released the piston remains in the same position, the internal mechanism is backed away from the piston, not affecting pedal travel/feel.
To change pads the motor is operated in the release direction until it reaches a stop, then the piston is pushed in as you would with a front caliper.
After pad replacement the motor is operated in the apply direction to the cut off point, then released to seat the pads and take out any free play.
There are other functions the oem control unit is capable of(such as pad wear warning) that would not need to be replicated.
It's unlikely that the oem control unit could be used with a kit, as it relys on can bus data from multiple ecu's to operate which would be a nightmare to try and simulate.

A safety system so the brake could not be accidentally released is essential, ie foot brake application required to activate release switch, or 2 separate switches operated together to release, mirroring the function of oem systems.
A handbrake 'on' lamp would be tricky to implement as it will need to store the status of the caliper while powered off, it would not be an mot issue though.

Most requirements for the mot would be covered by the caliper design itself, the epb malfunction lamp function would be a null point as you won't have one (there is no rfr for epb lamp missing), and the brake effort would be tested as normal in brake rollers.
I can see a decelerometer test being impossible as the caliper will apply to a lock (this is only an issue if you have a plate lsd), oem systems don't apply the handbrake mechanism while moving, they apply the service brake via the abs unit instead so also cannot be decelerometer tested.
I'm not sure if there will be any updated mot testing procedure as the electronic handbrakes are becoming the norm on a lot of cars, at present only a mechanical handbrake is tested in regards to accidental release, it may change to include this for electronic systems.
I don't know how the iva deals with home brewed epb systems, also the iva regs may give some idea of what changes might happen with the mot.

Dave


itsawindupuk - 10/2/16 at 10:31 PM

quote:
Originally posted by Dingz
Use MGF ones, keep it in the family as it were.
I think I have an old set somewhere?



Dingz, I did think about the F ones and looking at them online looks like they have a "pull" rather than turn for the handbrake mechanism which is how the current drums work. Could be interested in your old ones

Adam


itsawindupuk - 10/2/16 at 10:32 PM

quote:
Originally posted by obfripper
The passat caliper has an integrated motor, it's not much heavier than an ordinary caliper, other models also have a cast iron version that is heavier.
The aluminium passat version does have one caveat, they slowly corrode, the pressure of which eventually cracks the plastic motor housing letting water into the motor/electrical connector followed by failure, this probably wouldn't be an issue with a kit kept in the dry.

It wouldn't be too hard to use in a kit application with some ic's, relays and auto resetting polyfuses, using basic operation knowledge.
Under normal operation, the control unit operates the motor in the apply direction to a preset current(iirc 20a per caliper) then cuts off, and in the release direction for a preset time period (iirc 2 seconds).
When released the piston remains in the same position, the internal mechanism is backed away from the piston, not affecting pedal travel/feel.
To change pads the motor is operated in the release direction until it reaches a stop, then the piston is pushed in as you would with a front caliper.
After pad replacement the motor is operated in the apply direction to the cut off point, then released to seat the pads and take out any free play.
There are other functions the oem control unit is capable of(such as pad wear warning) that would not need to be replicated.
It's unlikely that the oem control unit could be used with a kit, as it relys on can bus data from multiple ecu's to operate which would be a nightmare to try and simulate.

A safety system so the brake could not be accidentally released is essential, ie foot brake application required to activate release switch, or 2 separate switches operated together to release, mirroring the function of oem systems.
A handbrake 'on' lamp would be tricky to implement as it will need to store the status of the caliper while powered off, it would not be an mot issue though.

Most requirements for the mot would be covered by the caliper design itself, the epb malfunction lamp function would be a null point as you won't have one (there is no rfr for epb lamp missing), and the brake effort would be tested as normal in brake rollers.
I can see a decelerometer test being impossible as the caliper will apply to a lock (this is only an issue if you have a plate lsd), oem systems don't apply the handbrake mechanism while moving, they apply the service brake via the abs unit instead so also cannot be decelerometer tested.
I'm not sure if there will be any updated mot testing procedure as the electronic handbrakes are becoming the norm on a lot of cars, at present only a mechanical handbrake is tested in regards to accidental release, it may change to include this for electronic systems.
I don't know how the iva deals with home brewed epb systems, also the iva regs may give some idea of what changes might happen with the mot.

Dave


I think there would be a market for something that could use the epc callipers. After a little research I think id struggle with the wiring if it wasn't a simple case of on and off.


big-vee-twin - 11/2/16 at 08:37 AM

I have 4pot Wilwood up front colour black and powder coated (high temp) black Sierra hand brake calipers on the rear - was the simplest solution after considering others. Look OK works fine.


mcerd1 - 11/2/16 at 10:28 AM

I used these guys to recondition a few sets of calipers and paid the little bit extra to get them in a long lasting coloured finish (black for the tintop) - the guys are really helpful and pretty quick too
And they supply the parts if you want to rebuild them yourself.

http://www.biggred.co.uk/

The finish is never going to be as good as fancy alloy calipers, but its not bad - and on the tintop they still cleaned up pretty well after 3 years of abuse (I never wash my tintops either...)

[Edited on 11/2/2016 by mcerd1]


b14wrc - 11/2/16 at 12:30 PM

Hi,

It might be of little interest, but ive just bought some Omega V6 rear calipers for my locost. These are twin pots with 40mm diameter pistons.

Im planning on making a central expansion plate, to allow for a 22mm wide disc and fabricating my own hand brake system in the caliper - i saw one willwood do on a four pot....

As usual im experimenting but i reckon it will compliment my front brake set up of Brembo 4 pots and 305mm discs....

I will post photos at the weekend if its of interest. Electronic hand brakes dont do it for me im afraid, thats why i just bought a GT86, wanted a new car but somthing that didnt have too much assistance - like my old Lotus Elise. Seen many of these on ebay while i was researching what i wanted.

Rob


nick205 - 11/2/16 at 03:37 PM

quote:
Originally posted by obfripper
The passat caliper has an integrated motor, it's not much heavier than an ordinary caliper, other models also have a cast iron version that is heavier.
The aluminium passat version does have one caveat, they slowly corrode, the pressure of which eventually cracks the plastic motor housing letting water into the motor/electrical connector followed by failure, this probably wouldn't be an issue with a kit kept in the dry.



Hmmm, I didn't know that about the motor in the caliper, makes sense.

In operation on the Passat you have to have the foot brake on to activate the EPB. It will however release itself without the foot brake being on for hill starts etc.