Rear Brake stuck on?

[StuartFZR400 0]

For the last week I've been getting a squeeking sound (louder when I wound down the passenger window) after a good 15mins of driving, but doesnt do it when the car is cold. After figuring out that its not likely the engine/alternator/rad-pump, I checked the wheels.

 

Jacked the car up and spun the front wheel - all good. Yet when I went to spin the rear it was very stiff and wouldnt spin more than 10deg once I let go.

 

Is this normal or would you say the rear brake is sticking on?

 

(the pads seem to be fine).

 

As you've guessed, Im thinking the rear pads are too close to the disc and getting too hot and thus squeeking.

[Supercharged 2]

It will be the caliper - very common problem on mk2/3 based cars...

[dinkus 10]

Sounds like it could be the old chesnut of a Corrado 'feature' - the ceased rear calliper :(

 

They usually cease off, but could just as well cease on. It sounds like the pads are brushing the disk just enough to generate heat and expand, so they only start squeaking proper after you've been driving for a bit and heated them up.

[StuartFZR400 0]

Thats what I thought Dom. So a "ceased" on caliper - I presume will be a b*gger to get off? Any handy hints on How To ?

:

 

I presume it could be a few things gone wrong; be it rusty parts/pins or worse. I guess if its the piston rusted then its time to buy a new one. (I've only had it on an old dirt bike cos it was rusty; once rust removed all was good)

 

 

:

Seems I will be taking the callipers off this weekend, as I've got an MOT next Tuesday. From what people have written before it maybe just a case of rust etc. After a good search on here (lots of different problems, but thanks for hint on "seized caliper"), I found lots of helpful hints - so will start with the cheapest:

The rear brakes also have the hand brake mechanism which through a cam type setup internally push the piston out when you pull up on the handbrake. As you have seen, when you move the lever on the end of the calliper the piston comes out and stayes out. That is normal as there is no disc and pads to stop the piston coming out. When people talk of seizing callipers it is the piston not being allowed to move back a little by the mechanical mechanism which causes the pads to be kept against the disc. Internal corrosion can also have the same effect by jamming the piston. Hope all that is not too full of bull!! Good luck.....

 

Failing this, is the Mk4 upgrade for VR6 only?

[dinkus 10]

Mk4 rear callipers will fit all Corrados :)

[Supercharged 2]

Yep - and the mk4 setuop and hoses should hopefully be cheap at Inters...

[StuartFZR400 0]

Now theres an idea. Any idea of cost - so I know Im not getting ripped off?

[Supercharged 2]

PM replied to but basically £50 a caliper (new) and £21 for pair or hoses at a show but that was 2 years ago...

[StuartFZR400 0]

Meanwhile Im taking the current ones off to see if they are just in need of a clean up. I checked my Lindsey book (so poor) and its fairly vague. I get the idea all you need to do is:

 

Can anyone confirm?

1. Take the brake-cable off (how? is it screwed on)

2. Remove the two holding bolts on the caliper top part and lift off, showing the gubbins of the pads etc. Remove entire caliper.

3. Take pads off caliper (cant see any spring clips in book)

4. clean up pins, pads

5. look at piston, see if it has a rubber sheath over it. See if piston is rusty and thus broken seal. If not...

6. put back together*

 

* do you have to screw the piston back in? And if so, does it require a special tool?

[dinkus 10]

You definitely need to screw the piston on the rear brakes back in, so you'll need a brake windback tool (Halfords and GSF sell them for about £15).

 

No idea on the rest of it tho - I've never really played with the rear brakes myself.

[Toad 0]

The bolts on mine were super tight, it may be worth giving them/the caliper carrier a wack with a hammer to help loosen them up.

I just used pliers (possibly circlip pliers or some long nosed beasts) to wind my pistons back in if i remember rightly. It is a bit fiddly tho.

[dinkus 10]

PlusGas or failing that, WD40 is your friend - douse the bolts (not the pads or disk!) in it and leave it a few hours before you start...

[StuartFZR400 0]

cheers guys, WD40 + brakes = bad idea , lol. I know.

 

Thanks Toad, shock can often break rust on a bolt, even hitting it to tighten firstly can really help. Will use Locktite to do them back up too - as The Book says to buy locking bolts. Copper slip on the shaft of the pins & bolts will prevent future rust.

 

Glad to hear that the piston might wind back in with other methods. Obviously avoiding boooogering the outer shaft.

 

Im still not super clued up on the piston. I take it that the piston should go back slightly of its own accord, to allow a cap between pad and disk in normal use. If I wind the piston back in, will it push back out when I put the brake on - will it need pumping?

[StuartFZR400 0]

Right, thanks guys. I got to the bottom of the problem... I hope. Took me all sunday, hence I couldnt come to Inters both days. The caliper sliding pin had rusted in because the tiny rubber boot was split. Still unsure if piston is working ok, so wait and see. Wish I had the correct turning tool for that, but there were non at Inters either.

 

For anyone who needs pics of the rear discs:

 

, .

 

Not sure I know enough to make a Wiki, however I went as follows:

You require: 15mm open spanner, 13mm socket, Copper Grease, Locktite (or locking bolts to replace old), screwdriver, *correct Piston Return Tool. Ensure the car ignition is off before doing this.

 

1. Having jacked the rear of the car up and taken the wheel off you can see all you need. Ensuring the car is in reverse gear and the front wheels are chocked, you can take off the handbrake cable by removing the holding clip (pic B) and lifting the nipple out of the arm - the cable+clip maybe rusty so WD40 it and give a good tug.

 

2. Crack the two bolts (pic A) that hold the Caliper in place with the 13mm socket, whilst ensuring the inner bolts (pic C) do not turn with your 15mm spanner. Take these two bolts out. Lift caliper off (maybe rusted on so jiggle). Remove pads (again maybe rusted in).

 

Pending what you are doing will change what you're doing next. I noticed my pin (pic C) that slides through a rubber boot (pic D) was not moving and not allowing the caliper to move thus keeping my brake on. The two pins should move in and out easily.

 

3. I removed the pin with great difficulty because of the rust. The boot should be pulled back first. I filed it down + emery, including inside the hole and greased up.

 

If you're replacing pads, it seems you need the *caliper return tool.

 

4. Putting new pads on is easy. However (not so easy) Discs should be replaced if worn - this is a bigger job and I didnt go that far. However, note that the piston needs to be pushed back by using your *return tool. You need the holding spings off your old pads and put onto the new (maybe lightly grease too).

 

Putting everything back in reverse there are a few pointers:

a. grease where ever you can but not the face of the pads or disc. You can do the rear of the pad and sides. Ensure the pads slide easily upto the disc.

b. ensure the (A) bolts have locking thread or similar.

[PhillT 0]

:thumbleft: nice write up there, going to replace all the friction parts + braided hoses before mine's on the road, this will help me on the rear brakes

[StuartFZR400 0]

Phoned VW = £11 for the rubber boot (D) off VAG - ouch !!

 

Glad that was of help Phill , just ask if you need more help; at least pic 2 shows the piston and the indentations where the *special tool goes. But as said, I never took off the housing/disc and nor did I replace the caliper. I think that work involves depressuring the ABS system and bleeding it. Handbrake cable should be easy enough, although there is a pin that needs lining up once a new one is placed in.