Rear Calliper problems 1999 N/A 1.8

[Steve_D]

Hi guys on way to work tonight, i noticed that when i released the handbrake... then try to apply it again... its got a bit of loose travel. so i carry on driving as i have to be in work. Noticing that its slower at take off than usual, i realise that the caliper is pressing on the disk!

Its only a short drive to work though lol.

So i get to work and the brake area is really hot and Smells! it has happened before, took the wheel off and with a set of grips 'wiggled' back n forth the handbrake arm on the calliper it did the job. but now (about 4 months later) its happening again.

Any suggestions?
Anyone have a guide to stripping the calliper down?

 

[spartacus 68]

Not unusual at this time of year with road salt, damp, and general dirt. I tend to leave the car in gear when it's frosty (on the flat) to avoid stressing the handbrake cable and dreaded sticky piston syndrome!

I did this job back in the Autumn and its been fine since. I replaced the rear calliper seals too as its not unusual to get a sticky piston as well as the sloppy handbrake. The kit is inexpensive from main dealer and allows you to do both rear brakes. It includes new rubber dust sleeves, 'o' ring brake seal, etc. Soak the components in the solution the comes with the kit before assembly.

Remove road wheels, brake carrier, etc. Pump brake to extend the piston from the bore. I used a brake pipe clamp so fluid loss was minimal. Remove piston bore, clean up, etc. You'll need the wind back tool to reinstall. Insert the new 'o' ring seal and lightly lube with a little brake fluid. Insert the new dust sleeve on the piston bore and lightly lube with Lockheed red grease. Bit fiddly to install, but patience is key. Remove the brake clamp. Open the brake bleed valve and wind the caliper in. Close off nipple, etc. You'll need to bleed brakes afterwards to expel any air.

Clean the brake carrier and lube the slider bolts. Don't use copper-ease. Again, red grease is fine.

Now the handbrake itself. Release the handbrake. Think the bolt that holds it on is 10-12mm from memory. Pop it off and remove the spring. There's a little Allen key bolt that holds the mounting plate to the back of the calliper. Ensure its clean and the hex tool sits in it properly before trying to release it or you'll round it off.

Pop it off too. Thoroughly clean the back of the calliper, taking care not to damage the rubber seal. Use a decent marine grease, Duckhams yellow grease is perfect and lube the area before putting the mounting plate back on. Now put the spring back on (having wire brushed it and lightly greased it), then the final 10-12mm nut and tighten. Don't over-torque it.

While you're there check the handbrake cable itself. Not unusual for it to corrode at the end. You can lube this area slightly too. Any doubt about the condition - then replace. Similarly, if this does't work for the handbrake and its sloppy, then in needs to be disassembled inside the caliper which means removing the circlips, etc, which is more hassle than its worth. Go for an exchange unit from Audi.

Hope that helps.

More details here from an early A6 regards rear brake caliper dismantle (handbrake). I'm sure it's the same for a B5.
rear caliper rebuild guide - AudiWorld Forums

 

[Steve_D]

Well!...

Thanks for that info Spartacus, and that guide, its pretty similar to my caliper(s) and definatly one that i will be using. I'll get the new seal kits and strip all 4 calipers down Never one to shy away from a bit of DIY, in fact i do all of my own, if i dont know.. i ask or research! 'you never learn if you don't try'

Think i will also give them a lick of paint whilst im at it, after a full clean up.
I'd rather do that than take it to a garage and have them replaced... it solves the problem, but learned nothing.

Going to be doing alot of work on my car this year, so you'll see me asking alot of questions haha
Wish i had done that when i replaced the rear disks and pads early last year....

But i think i will have to address the Rear Exhaust box first as it has a 'split' on the seam.. the same side as the rear passanger caliper, which in turn will be blowing crap onto the caliper.

you mentioned the brake pipe clamp.. i thought them pipes had metal in them (i have never replaced one so unsure) and didnt want to clamp them thus damaging the pipe, so that is safe to do so?

 

[spartacus 68]

You mentioned the brake pipe clamp.. i thought them pipes had metal in them (i have never replaced one so unsure) and didnt want to clamp them thus damaging the pipe, so that is safe to do so?

I mean the flexible brake pipe that connects to the fixed copper pipe. I've never had a problem using the Draper tool, but some members on the forum don't recommend them because of concerns about the pipe collapsing. Your call though. You can use a little cling film over the brake fluid reservoir too, then reattach cap to minimise fluid when doing this job. You can check the condition of the flexible pipes as part of the brake service. Front brakes are a lot easier. No need to do the 'o' rings unless you suspect a sticky piston. You can remove pads and extend piston out and then lightly apply red grease with a blunt tip screwdriver under the dust sleeve.

 

[Steve_D]

ahh i dunna mind using the tool if it works lol

I did inspect them when i had the wheel off yesterday, i took a big set of pliers and gave movement back to the handbrake lever on the caliper, the seal there is in tact but years of abuse/ use and dirt will obviously get in there, which is obviously the problem i have.

I'd rather take them all apart and give them a thorougher job of it. just been on biggred.co.uk and rears are £26 and front £25 for a set! Thats pretty cheap in my eyes.

Whats the best grease to use on the sliders and the inners on the handbrake?
Also, easiest method to bleed the system after?

 

[spartacus 68]

I use Lockheed red grease on any brake rebuilds as its specially formulated for hydraulics, and no issues with rubber. Regards the handbrake, any decent marine grease will work, however not sure about the internals if you're looking to extract the circlips and completely dismantle.

Regards bleeding brakes, the old fashioned manual way is best. Use to get my wife to pump the pedal while I went from wheel to wheel. She soon got wise to my ploy (out in all weathers) and now refuses to do it, so I bribe my youngest daughter instead with increased pocket money!

Start with wheel furthest from brake reservoir and do each in turn, topping up the reservoir with DOT 4 fluid as you go. So that's N/S rear, O/S rear, N/S front, and finally O/S front. Make sure you have a closed end spanner on the brake nipples. They round easily.

Regards the brake kits, Audi are pretty reasonable. Biggred stuff looks good, and particularly like the polymer coating, very, very nice.

 

[Steve_D]

cool, cheers for that!

I will ring audi and see what their price is like. but to me Biggred (as they specialize in brakes) will be the same or an equivalent. just Audi will be a premium price i think haha

Im also going to buy the bleed nipples too, as i know mine are showing signs of rounding. Their still fine to use.. but im goig for the rebuild.. so its buy new lol

Im hoping to get a finish near to that "look" with some spray paint.. so long as i clean them enough it should look good lol

I'll document everything, and stick it in the DIY section when i do it... probable at the end of the month (Tax and tyres was this month)

March will consist of T-Stat replace and Brake rebuild

Thanks for all your help and info... if i get stuck when i do it... i'll have to come back on here haha

 

[aragorn]

I got a whole recon caliper fro £50 from ebay for my mums A4, no point messing around rebuilding them when they're that cheap!

 

[Steve_D]

I got a whole recon caliper fro £50 from ebay for my mums A4, no point messing around rebuilding them when they're that cheap!

i've had a butchers on ebay but couldnt find any, plus id rather have a go at it myself.. learn something new.
the only thing im worried about is when i take the caliper off the brake fluid is just gonna empty.

Spartacus mentioned to use a clamp, is their any other way?

 

[aragorn]

The problem is the handbrake shaft.

You can do the main seal easily, but the handbrake mechanism is fiddly. I tried to take one apart to see what it was like, and in the end sacked it off and gave up as it was just too awkward.

AUDI A4 1.8 PETROL REAR BRAKE CALIPER RIGHT HAND R/H 1995 2001 | eBay

When a new caliper is 50quid delivered, it really doesnt make any sense rebuilding, as you'll spend 20-30quid on seals, and another 20-30quid each side for replacement pistons.

 

[Steve_D]

i know what you are saying, i've added that to my watch list lol. i need to search harder next time haha

I've just got it in my head that i want to service them, i kinda dont let things go. Like to see the problem and try to rectify it, which isnt a bad thing

rear caliper rebuild guide - AudiWorld Forums
that thread spartacus gave me tells mehow to take it apart completely, pretty usefull too. So im gonna give it a blast, if all fails, i will get that one from ebay