Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
9/14/19 12:01 p.m.

I am planning out the rear brake setup for my Fiat. The calipers I am using do not have parking/emergency brake provisions.  I do however have a few of these Airheart style Wilwood units floating around

These things seem atomically crappy. Odd slider arrangement, loose inner pad that looks like it will rattle itself into a pebble with regular use. They are an expensive version of a $15 gokart caliper without any upsides.

Has anyone used these for a parking brake like they are marketed? Am I overthinking things and they will be fine?


I have found a few pics of them installed like this

If I can make them work they would be great. That mechanism, lack of a proper slider and the loose rattling pad scare me though.

Knurled.
Knurled. MegaDork
9/14/19 12:53 p.m.

If they are an expensive kart caliper, why not use kart calipers?

 

Speaking as someone who wants to stick four piston calipers at all four corners of a car for which there is no easy drum parking brake solution.

Knurled.
Knurled. MegaDork
9/14/19 12:58 p.m.

OOh... looks like something like this could easily be spaced wider for any thickness rotor you care to stick it over.

 

It will probably work better than an 80's VW handbrake, at the very least!

Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
9/14/19 1:16 p.m.
Knurled. said:

If they are an expensive kart caliper, why not use kart calipers?

Because I already have them!  I got them for a project at work, no one like the look of them and then Wilwood came out with the mc4 series so we used those instead.  These have been on a shelf for years and would be free.

The mc4 parking calipers are wonderful and not terribly expensive but free is too tempting to resist

Gn0m4
Gn0m4 New Reader
11/7/19 12:52 p.m.
Jumper K Balls (Trent) said:
Knurled. said:

If they are an expensive kart caliper, why not use kart calipers?

Because I already have them!  I got them for a project at work, no one like the look of them and then Wilwood came out with the mc4 series so we used those instead.  These have been on a shelf for years and would be free.

The mc4 parking calipers are wonderful and not terribly expensive but free is too tempting to resist

 

How powerfull MC4 is?

I have a Miata and would like to mount Powerlites at rear but need some mechanical caliper to pass MOT (so need at least to brake like the oem) and park in the street.

I´m watching this MC4 and Mech one but i can´t find any people with those.

 

Thanks !

californiamilleghia
californiamilleghia Dork
11/7/19 1:15 p.m.

Are there OEM calipers with a mechanical  parking brake built in ?

Junkyard or Rock auto ?

Rodan
Rodan Dork
11/7/19 3:29 p.m.
Gn0m4 said:

How powerfull MC4 is?

I have a Miata and would like to mount Powerlites at rear but need some mechanical caliper to pass MOT (so need at least to brake like the oem) and park in the street.

 

Flyin' Miata sells a rear Powerlite kit with parking brake.

FM rear Powerlite kit

I have it on our NA track car, and the parking brake is very true to their description... not very powerful, but it does work.

RossD
RossD MegaDork
11/7/19 5:45 p.m.

In reply to Rodan :

Thats similar to the parking brake on the Renault 8, but it is just lever action is on only one side.

 

Gn0m4
Gn0m4 New Reader
11/8/19 12:28 p.m.

In reply to Rodan :

That was my first option. Very simple bracket fabrication (because radial mount and only one caliper per side) but it doesn´t work very well.

In fact a close friend has it and it doesn´t pass mot, even pulling the lever like there's no tomorrow. He can´t park the car in a ramp because that system doesn´t stop the car without a gear engaged.

I thought in a force multiplier (pulleys) to put between caliper and lever but all design are very tedious and I really don't know what will stop.

So, very curious about the force of those MC4 and Mech caliper.

Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
11/9/19 12:47 p.m.

I have no way of measuring the force the mc4 applies and it isn't listed in any of the Wilwood documentation.  I will say that the mechanism seems to be up there with most OEM style parking brake systems I have played with. It seems like an absolute gem of a caliper especially when comparing it to the almost equally priced spot caliper. 

Two times in my life I have been in situations of complete brake failure with no mechanical backup option. It takes a shockingly long distance to scrub off 40mph and bashing into a curb as the only option to avoid little old ladies in the fabric store parking lot was a lot more brutal than I anticipated.  I won't let that happen again.  Because of this I decided the Flyin' miata powerlite option wasn't good enough.  

So I have been trying to find a middle ground for effective, inexpensive and lightweight.  Pick any two, right?

Last time the fiat was terrorizing the streets it used Tokico calipers off of a gixxer sport bike, and you know what? They were freaking amazing.  The best brakes I have ever had on a project car and they shaved 7lbs of unsprung weight per corner.  I am going back to that setup on all 4 corners for the rebuild. 

I will admit I have started to machine my own parking calipers. There are some distinctively shaped chunks of 6061 on my mill table. If I get further with that project by the time I start machining the new rear bearing carriers I might go that way, but the mc4 seems like a better choice as far as safety goes. 

californiamilleghia
californiamilleghia Dork
11/9/19 1:18 p.m.

Do all the other cars with 4 wheel disc brakes also have a  small brake "drum" in the rear hub for an E-brake ?

Just seems like there would be a few more cars with the combination brake caliper  and  mechanical  E-brake in one unit , 

Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
11/9/19 1:36 p.m.

Oh there are! They just tend to be cast iron single piston slider calipers.  

 

I'm sure I could make say... NA Miata calipers work just fine. I however simply want 4 wheel, 4 piston calipers. Be that right or wrong.  

Knurled.
Knurled. MegaDork
11/9/19 1:43 p.m.

In reply to Jumper K Balls (Trent) :

Lucas made some rather nice aluminum integrated handbrake calipers for VW.  I am using them specifically because they are aluminum.

 

I totally understand wanting fixed calipers all around, which is where my interest in this thread comes into play.

Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
11/9/19 1:56 p.m.

I have already developed the hardware for powerlites. But for my budget I think the 1400 could be shifted elsewhere and since I already own the tokicos......

 

californiamilleghia
californiamilleghia Dork
11/9/19 2:07 p.m.
Knurled. said:

In reply to Jumper K Balls (Trent) :

Lucas made some rather nice aluminum integrated handbrake calipers for VW.  I am using them specifically because they are aluminum.......

What model VW are they on ? 

Was there ever an Ebrake  that used separate  hydraulic lines , calipers and master cylinder , much like a steering brake ..

Would that pass MOT for you ?

Jumper K Balls (Trent)
Jumper K Balls (Trent) PowerDork
11/9/19 2:29 p.m.
Knurled. said:

I totally understand wanting fixed calipers all around, which is where my interest in this thread comes into play.

The MC4 has got to be the best bet by far. Especially considering how similarly priced and how much fabrication is required for the Spot. But if one was going with the airheart style there are dozens of identical options under $50.  The loose pad and the fact that they are intended to be mounted from above the rotor is just sketchy.  Thanks speedway customer service for recommending them to me frown

Trying to make that clean, safe and reliable inside a 13" wheel is just off the table.

Knurled.
Knurled. MegaDork
11/9/19 2:42 p.m.
californiamilleghia said:
Knurled. said:

In reply to Jumper K Balls (Trent) :

Lucas made some rather nice aluminum integrated handbrake calipers for VW.  I am using them specifically because they are aluminum.......

What model VW are they on ? 

Was there ever an Ebrake  that used separate  hydraulic lines , calipers and master cylinder , much like a steering brake ..

Would that pass MOT for you ?

In order:

Calipers are from any A4 chassis Golf/Jetta/New Beetle.  There is also a variant for B5 A4 quattros (and contemporary A6 quattros) that have the cable entering at a different angle, and a variant for D2 A8s which had large vented rotors instead of little 10mm solid disks.

 

No.  They are all cable driven, except for the modern ones that are electronic.  It actually used to be in the FMVSS that cars sold here had to have a mechanically operated brake on at least one axle, but clearly this has been changed since so many cars have electric ones now.

You can plumb a master cylinder inline with the rear brake line (or lines) if you want a separate control of the same brake.  Rally cars do it this way.  I have one in the RX-7, works great. 

 

I don't know about where Mr. Balls lives, but we don't have any kind of vehicle inspection here except for emissions testing for cars newer than 25 years old.  I however trust hydraulics to hold a car still longterm about as far as I can throw them, I want a mechanical device.

Ian F
Ian F MegaDork
11/9/19 2:59 p.m.

How about a small two-piston hydraulic caliper with a small master cylinder operated by the hand lever?

Gn0m4
Gn0m4 New Reader
11/11/19 6:52 a.m.
Jumper K Balls (Trent) said:

I have no way of measuring the force the mc4 applies and it isn't listed in any of the Wilwood documentation.  I will say that the mechanism seems to be up there with most OEM style parking brake systems I have played with. It seems like an absolute gem of a caliper especially when comparing it to the almost equally priced spot caliper. 

Two times in my life I have been in situations of complete brake failure with no mechanical backup option. It takes a shockingly long distance to scrub off 40mph and bashing into a curb as the only option to avoid little old ladies in the fabric store parking lot was a lot more brutal than I anticipated.  I won't let that happen again.  Because of this I decided the Flyin' miata powerlite option wasn't good enough.  

So I have been trying to find a middle ground for effective, inexpensive and lightweight.  Pick any two, right?

Last time the fiat was terrorizing the streets it used Tokico calipers off of a gixxer sport bike, and you know what? They were freaking amazing.  The best brakes I have ever had on a project car and they shaved 7lbs of unsprung weight per corner.  I am going back to that setup on all 4 corners for the rebuild. 

I will admit I have started to machine my own parking calipers. There are some distinctively shaped chunks of 6061 on my mill table. If I get further with that project by the time I start machining the new rear bearing carriers I might go that way, but the mc4 seems like a better choice as far as safety goes. 

 

 

Thanks Man

I think i will go with Powerlites and MC4. This the best and only Wilwood option for my 12mm / 290mm rotors.

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