anyone tried vw passat/audi a6 calipers on the rear of their pre 85 cars?

[82s3]

I read this post several times a while back, thought about it and decided to have a go, because my handbrake has always been a bit naff.

In case it did'nt work, I've initially bought just a nearside Audi A6 caliper (brand new & only £20 on eBay) which I've found you need to fit on the offside in order place the bleed nipple uppermost. There's a bit of a knack to getting the calliper in place because there isn't much space - the rear chassis loop that runs under the gearbox gets in the way. This loop also runs very close to the bleed nipple, so bleeding the rear brakes may be easier said than done.

Anyway I got the calliper in and then fiddled a new set of A6 brake pads into place and bolted it up, no problem and it slides without fouling the carrier.

The bracket on the calliper that retains the handbrake cable outer ferrule needs to opened up a little so that it will slide in. Once this has been done, the cable fits and works as normal. I opened it up with a conical grind stone in a drill.

Routing the nearside handbrake cable is up the side of the engine bay, past the coolant header tank and the down to the caliper. No problem.

Last job is the brake line. This is a different fitting at the calliper end - it needs a banjo. I'll call PNM tomorrow to see if they'll sell me a set.

Bob

[giorgio67]

Hello Bob, did you buy the right hoses from PNM in the end?

How much are the set?

Thanks

G.

[82s3]

Hi Giorgio.

No, I haven't had to buy new hoses because my rear hoses are stainless braided items with reusable banjos.

I have therefore simply bought some replacement banjos (eBay) and fitted them to the existing hoses.

Things to note are,

1) The Audi calipers take an M12 x 1.00 thread banjo bolt.

2) You therefore need to buy a couple of M12 banjo's. Best to buy items that come with the compression fitting and olive as this saves buying parts piecemeal.

3) The Audi calipers are a direct replacement for the original Girling units - no modification necessary. Note though that the left hand Audi caliper is fitted to the Esprit's right hand side and vice versa.

4) The right side handbrake cable runs up the side of the engine bay and then and then down past the cooling system's expansion tank, to the caliper.

5) The left hand side handbrake cable run up over the top of the bell housing and then down to the calliper. It runs a bit close to the exhaust and so it's best to wrap it with some heat resistant sheathing.

The calipers cost - £45; brand new units from eBay.

Brake pads - £20.

Brake hose banjos and banjo bolts - £50.

Total cost £115 which is about a 1/3rd of the cost of PMN's "kit".

I think that covers everything save to saw that the handbrake operation is far better than Girling units.

Bob

 

 

 

 

 

 

 

 

[ekwan]

2 hours ago, 82s3 said:

Hi Giorgio.

No, I haven't had to buy new hoses because my rear hoses are stainless braided items with reusable banjos.

I have therefore simply bought some replacement banjos (eBay) and fitted them to the existing hoses.

Things to note are,

1) The Audi calipers take an M12 x 1.00 thread banjo bolt.

2) You therefore need to buy a couple of M12 banjo's. Best to buy items that come with the compression fitting and olive as this saves buying parts piecemeal.

3) The Audi calipers are a direct replacement for the original Girling units - no modification necessary. Note though that the left hand Audi caliper is fitted to the Esprit's right hand side and vice versa.

4) The right side handbrake cable runs up the side of the engine bay and then and then down past the cooling system's expansion tank, to the caliper.

5) The left hand side handbrake cable run up over the top of the bell housing and then down to the calliper. It runs a bit close to the exhaust and so it's best to wrap it with some heat resistant sheathing.

The calipers cost - £45; brand new units from eBay.

Brake pads - £20.

Brake hose banjos and banjo bolts - £50.

Total cost £115 which is about a 1/3rd of the cost of PMN's "kit".

I think that covers everything save to saw that the handbrake operation is far better than Girling units.

Bob

 

 

 

 

 

 

 

 

Can I ask which Audi/VW model do the calipers come from?

[82s3]

Audi A6

Bob

[naasaa]

These are ones to go for. 
they have 41 mm pistons. 

[LotuStuart]

On 12/01/2020 at 18:08, 82s3 said:

This loop also runs very close to the bleed nipple, so bleeding the rear brakes may be easier said than done.

I have no idea if this suggestion might help-but perhaps you could bleed the calipers before they are bolted in to place- that might be simpler?

[82s3]

Actually bleeding the calipers wasn't the problem that I thought it would.

Bob

[Andyww]

What we need is a part equivalent caliper from a car with electric handbrake, if ever available.

I have been looking at the system in my Renault. All of the handbrake, cables, linkages etc are thrown in the bin and the brake is operated by a small 12v motor on the back of each caliper which winds a screw in or out to push the inner pad forwards or not. Dead simple. No adjustment, no seizing.

In normal cars they have an electronic controller which probably monitors current and turns off the motor when it reached a torque limit but I am sure it could work just as well with a pushbutton for each direction.

[drdoom]

Quite in agreement with Andy, I hope to equip my S2 with electric parking brake ( EPB ). These things are becoming ubiquitous and do function well, as I found when running about France and Belgium in a hired Renault back in '14. These are fine times for those who wish to update mechanisms, with clever widgets of all sizes now easily obtained. The American firm Wilwood has already presented EPB calipers and several kits for their use, while PNM did appear to be moving on an Esprit fitment. I believe there are aftermarket and OEM calipers with EPB function now showing up on EBay.  No question the OEM operating lever placement is infernal on Esprit. 

[82s3]

How about just keeping things simple with traditional handbrake cables. Less to wrong!

Bob

[Andyww]

On 24/03/2020 at 19:54, 82s3 said:

How about just keeping things simple with traditional handbrake cables. Less to wrong!

Bob

My point is that the electric systems are simpler. Apart from the linkages and cables which can seize up, the ratchet mechanism in the calipers is prone to fail and wont work at all unless the cables are free and adjusted for the correct amount of play. The appeal of the electric system for car manufacturers is clear, far easier to build and no adjustment needed. Even backing off the system to retract the pads for replacement is easier.

[Mark Wainwright]

On 16/02/2020 at 07:20, naasaa said:

These are ones to go for. 
they have 41 mm pistons. 

Wondering, did anyone try these larger piston diameter calipers?  I haven’t got around to this job just yet, but curious if the larger diameter versions fit the same as the Passat ones for when I do get around to it. :)  Cheers!

[PhilW]

Im a bit lost here.  All B6 Passats had electronic handbrakes so how can these calipers work?  What am I missing?

[Andyww]

3 hours ago, PhilW said:

Im a bit lost here.  All B6 Passats had electronic handbrakes so how can these calipers work?  What am I missing?

Sounds great if they will fit. Wire up to Wilwood EPB controller, remove entire handbrake mechanism and ceremoniously throw in the bin, buy new sill carpet and cover the hole.

[Mark Wainwright]

Hi @PhilW the caliper that people have tested on here successfully is the passat 3B / 3BG and audi A6 caliper with manual handbrake.  people are speculating about using the electronic handbrake version too though..  but i dont think anyone has given it a go yet.  would be kinda neat if it worked!  whether the caliper itself fits or not and the electronics side (is it just a switch? or switches and sensors to confirm clamping pressure/ when to stop the handbrake motor?) are open questions at the minute I think. 
cheers,

Mark

[drdoom]

I'd very much like to lose the handbrake lever, as all here will appreciate. Looking at 2 methods that might be possible: leaving the cables and calipers as is, using a linear actuator to draw the cables tight; alternatively, utilizing calipers with internal electrical drive, as discussed above. I surmise the push button operation in use with the integrated calipers found in most modern cars works with controller circuitry which uses amperage level for determining clamping load. This would deliver foolproof reliability ( never more clearly in need 😉 ) if correctly engineered, but might be doable via momentary switch if in the hands of an intelligent human. The momentary switch might do for the linear actuator as well. Happy to hear from anyone who's made progress on this.

Cheers 

[Andyww]

Thats correct about how it works. The mechanism on the caliper is just a simple motor which winds a threaded plunger against the piston. The controller initiates the motion and trips out when a certain current loading is reached. The same when de-activating but winds out the other way by applying the voltage reversed, for a specified time period. The caliper mechanism is far simpler than a manual ratchet or other such system.

One of the reasons electric handbrakes have a bad name is the underhand way in which the car makers use it to lock people into using a main dealer for servicing. For example when changing the rear pads on a Renault I used to own, the official way is to take it to a dealer who connects to the ODBC and uses a special code which tells the controller to fully reverse the motor and wind out the plunger allowing the piston to then be pushed back. But the unofficial way which takes 2 minutes is remove 2 screws holding the motor to the caliper and manually turn the shaft fully until it stops, then refit motor.

It would be possible to do the controlling by 2 buttons but it would rely on the driver not holding the button pressed for too long after the brake is applied otherwise the motor could burn out. So it would be best to use a proper controller now they are available aftermarket. 

So the only limitation on whether this would work on an Esprit is whether the calipers would physically fit. They are wider owing to the motor.

[PhilW]

Personally I would keep my handbrake lever.  Not a particular fan of electronic handbrakes to be honest and just wouldn't want to install that in an Esprit.  I would definitely consider replacing the calipers as I mine do seem to provide me with problems, so a more modern unit from a major manufacturer could be the solution.  I think I will try and get hold of a set and have a look at what can be achieved relatively easily.

[GTK]

Nice to see this thread back, it's such an interesting read. I'm not a fan of electric parking brakes either, but realise that might just be old grump setting in. For me adding modern tech defeats the purpose of a classic. Maybe I'll recant later, but in the first instance I'd like to experience the Esprit as it was. 

I'm sorely tempted by the VW brakes, for the weight saving. That aspect makes the electric parking brake potential really interesting too. Not sure what extra components are needed, but the Esprit's twin parking brake cables are heavy, as is the lever. Plus not having to do the extra work to reinforce the body around where the lever mounts... 🤷🏻‍♂️

@910Esprit Steve, sorry for never acknowledging your request for brake dimensions. I either missed that or got sidetracked by my project. I'll be blasting all of my suspension/braking components in the coming weeks so if you [or anyone] still wants any measurements let me know. 

[910Esprit]

@GTK  Haha -  I'm waiting for you to get sidetracked by the Lotus again! 

Don't worry about brake dimensions (on my behalf).   I too have been sidetracked by other stuff!

 

[GTK]

 Just piecing together final mods on a blast cabinet and the project will kick off again for a final push. the chassis work really took it out of me.

[snowrx]

@ GTK Once you start blasting in a cabinet, it's only a matter of time before you're outside blasting the big bits with sand going everywhere! You can blast the black right out and clean up later.

I need to look into these brakes for the post 85 car, for when my rear calipers finally go...

[Mark Wainwright]

On 16/02/2020 at 07:20, naasaa said:

These are ones to go for. 
they have 41 mm pistons. 

Resurrecting this thread   

I`m just getting round to buying the parts for this now ( I`m back from NZ, hence the many years gap!!  )   Just an observation about tehse 41mm calipers.   it looks like the bleed nipple is on the other side of the caliper to the 38mm ones.   ie. 38mm ones have it on the same side as the handbrake bracket, 41mm ones have it on the opposite side at an angle.   
It looks like (having gone over this thread again), that this would mean you would have to either fit them with the handbrake cable attaching from underneath (probably not ideal?  not sure without trying),   or the bleed nipple at the bottom to keep the handbrake cable attached at the top (not ideal due to bleeding) .

would love to know if anyone has tested these out?   I might stick to tried and tested 38mm piston ones if not. 

cheers,

Mark

 

[Mark Wainwright]

also wondering, those who have fitted this. can you use the standard brake hoses, or do you need to fit a banjo and custom hoses as @82s3 Bob already had fitted to his esprit? 

cheers,
Mark