Advice on fitting rear handbrake calipers

[S2central.net]

I am copying (and elaborating) some text that accompanied refurbed rear calipers I got this week. In all my years I have not found a formal description for this task. I remember reading somewhere before that you cannot use the handbrake until the caliper is fitted, bled and that any gaps to the pads have been overcome - but this explains why that is important as if you get it out of sequence then the internal handbrake mechanism may need reset.

Warning -

Do NOT operate handbrake lever before fitting to the vehicle. The unit has been preset at the factory. If you operated the handbrake lever, then reset it as follows. The handbrake cable should be fitted last.

To reset the handbrake mechanism before fitting the caliper, the piston should be rotated IN (clockwise). When the piston is fully IN - then the piston should be turned OUT by 0.5 to 1 turn. The handbrake mechanism is now reset.


Adjustment & Fitting -

Adjust the pad gap on the caliper by rotating the piston OUT until there is no more than 1mm clearance between brake pads and disc.

Rotation of the piston should be done with the correct 'piston winder' tool. Fresh calipers can be rotated with care using long nosed pliers.

If the piston is rotated OUT too far for pad fitment then it needs to be rotated IN by at least half a turn to ensure the internal mechanism has reset.

Fit the caliper and brake pads and ignore the handbrake cable for now.

Bleed the caliper.

Finally fit the handbrake cable and adjust to remove any slack. Ensure the gap between lever and end-stop does not exceed 1mm.


Top Tip -

I found that I had to relax the handbrake cable tension by a considerable amount in order to fit the cable into the new caliper. Then I reapplied the tension while checking the clearance was good. This job is made VERY easy if you have a 10mm deep socket on 1/4 inch 'wobble bar' extensions so you can get to the tensioner in the tunnel without having to fight with the exhaust and heat shield.

[S2central.net]

Whilst on the subject of rear calipers..... I can confirm that the REAR RIGHT from Audi V8 fits to REAR LEFT on S2 (and vice versa) with vented disc conversion. This is because the caliper position is trailing on the V8 and leading on the S2... Means that the bleed nipple ends up on top.

Remember Audi V8 caliper is same as RR quattro and the AAN engined S4/S6 - it is a steel caliper with identical hydraulic fitting and handbrake setup.

I got mine from an eBay parts trader for £116 each including postage. I get refund of £30 on return of old calipers. Not a bad price and the calipers look to be very nicely refinished. Not as sexy as brand new but very cost effective.

The other TOP TIP - gunj a healthy amount of stiff water pump grease around the handbrake mechanism in the area where the gap otherwise attracts moisture and dirt.

[chris]

caliper

thanks, just about to fit new pads on my s4 nice remider

[PeterS]

Never had an issue - handbrake off when installing/removing the calipers, provides enough slack in the brake cable. removed the spring and the 10mm bolt from the handbrake mechanism on the caliper. Attach the caliper brake hose. insert brake cable into caliper handbrake lever using needlenosed pliers, careful not to tear the rubber boot. Bolt Caliper to wheel hub. reinstall 10mm bolt to retain spring, reinstall spring on caliper handbrake mechanism. Open caliper brake bleeder, attach hose to bleeder to drain brake fluid into container. use piston retraction tool to drive piston into the caliper, push out fluid. Close bleeder. Insert new pads onto caliper carrier and install Caliper. Ensure caliper guide pins are lubricated and move freely (High temperature water proof brake grease is fine). Afterwards, pull up handbrake repeatedly until you feel resistance (pads are touching rotor) start car and step on brake pedal.

(Have never touched the handbrake adjuster even after replacing brake cables)

[andy10v]

I second the slackening off the adjuster, long extension and its seconds to adjust up ad down, makes life easy and quick to hook the lines up. You don't have to remove caliper spring etc.

I didn't have a deep socket, but a box key in a socket works.



Peter do you not bleed the brakes when you replace a caliper then?

[S2central.net]

@Peter - the guide specifically says NOT to use the handbrake to take up the slack... maybe its just some FUD - only repeating what is recommended by caliper rebuilders.

[PeterS]

Paul:
I'm not disagreeing with you, just stating what has always worked for me.

I live in New England region of the USA, and between the snow and salted roads, under chassis corrosion makes maintenance an ongoing challenge.
I avoid tightening the handbrake rod adjustment bolt for the simple reasons that its difficult to access, and usually rusted to the threaded rod ;-).

As to why I open the bleeder when installing new pads - it makes it easier to turn the pistons back into the caliper, and also flushes any contaminants out of the caliper, vs back into the lines. Pre-filling a new caliper with brake fluid makes it easier to bleed. Flushing the brake fluid every two years is highly recommended. I use a Motive power bleeder - some folks fill the bottle with brake fluid, pressurize it by pumping the handle and then bleeding the brakes, I top off the reservoir and bleed until the reservoir is almost empty, disconnect the bleeder, refill the reservoir...it's cleaner than having to clean the power bleeder bottle and lines after completing the process

Bleeding order is from the furthest from the reservoir to the closest (which will vary from RHD to LHD vehicles)
If you are only replacing a caliper, you can get by just by bleeding that line.

[Phil Payne]

Some of this may be applicable:

http://www.isham-research.co.uk/quattro/caliper.html

(It hangs off http://www.isham-research.co.uk/quat...ro_brakes.html

[UrS4boy]

C4 UrS Rear Caliper R&R DIY

I guess you never saw this Rear Brake Caliper R&R DIY that I wrote some time ago:

http://forums.quattroworld.com/s4s6/msgs/16639.phtml

From the C4 UrS chassis and system map (click on the labels):
http://members.shaw.ca/speedtek/UrS%...sis%20Map.html

[Greg_S]

Will keep an eye on this thread, just about to send mine off to be refurbed

[UrS4boy]

C4 UrS Emergency Brake Cable Info

I should have added info about the e-brake cable to my previous post. This is C4 UrS-related but some of it should cross over to the B3/B4 chassis:

http://forums.quattroworld.com/s4s6/msgs/24448.phtml

[Val]

Beware that #17 part isn't there at all.

[Phil Payne]

News to me that you can buy guide pins separately - I've always thought they only came with new carriers. A shame there are no part numbers - just "Appropriate service kits are available".

Also any attempt to release the flexible hose from the body first on a rusty ur-quattro will take you straight into a world of hurt - don't tackle that unless you're replacing the fixed brake lines. Just crack the flexible line joint at the caliper and rotate the caliper off.

[re2500]

This whole guide and the lucas instructions posted above are great. Ive just stripped cleaned and rebuilt my coupe calipers and theyre as good as new!! In the past when i have had a problem with the handbrake mechanism getting sticky and rubbish ive always exchanged them for recon units. Ive saved loads by doing this myself this time. Luckily my seals and everything were completely fine everything just needed de-gunking, de-rusting, greasing up and rebuilding, now good as new!!

If a caliper requires new seals etc. then biggred supply seal kits for these calipers (on their website and on ebay) the kit is about £27 for seals for both calipers. biggred also list the Ford sierra/granada handbrake spring on ebay at about £7 each (which is NLA at Ford dealers) this is a direct replacement and supposedly slightly stronger. Guide pins are also available.

[5cylinderman]

You can wind the pistons all the way home on these calipers when changing pads etc. The trick is to driver the car for a day or two afterwards WITHOUT pulling the hndbrake lever. The caliper will slowly adjust itself with the action from using the brakes.

Another trick is to use the handbrake quadrant return springs from the VW Sharan/Ford Galaxy/Seat something or other. They are stronger that the older VAG ones.