Xantia rear brakes Please read its a strange one............

BrianA · Unread post by **BrianA** » 08 Jun 2007, 17:24

Well it is to me.
I recently changed the rear brakes on my temptation 2.
Other than having to replace the retaining pins and push the pistons back in in order to fit the new pads everything went along smoothly......
Until I put the wheels back on.
The hub moves freely by hand without the wheel on,the wheel moves freely with the wheel on and the wheel nuts in but not tight,
but as soon as I start tightening the wheel nuts the wheel locks up and I can actually lift the rear end of the car by turning the wheel.
As soon as the wheel nuts are loosened the wheel becomes free again.

I'm lost please tell me I'm thick and that its an obvious fix.
Bri

Xaccers · Unread post by **Xaccers** » 08 Jun 2007, 17:27

Look over the top of the caliper down onto the disc and pads, is the caliper lined up properly?
Mine had loads of corrosion between the caliper and the car, pushing it out of alignment which caused constantly squeeling brakes.

Stewart(oily) · Unread post by **Stewart(oily)** » 08 Jun 2007, 17:29

Corrosion between the caliper and the arm? this can grow to a few millimetres thick and stop the pads from going in or make em jam.
Stewart

BrianA · Unread post by **BrianA** » 08 Jun 2007, 17:33

Thanks for the reply Xac and Stewart(oily) I read your post on that in another thread and I will have a look.
Would this locking problem only happen with new pads as it didn't happen with the old ones?
Also why does it only lock up when the wheel is put on as the hub is as free to move as it should be without it on.
Cheers,Bri.

Stewart(oily) · Unread post by **Stewart(oily)** » 08 Jun 2007, 18:35

The old pads probably wore on the pi** and the new ones are square, also the disc is not really held solidly onto the hub, until you tighten the wheelbolts.
Stewart

Xaccers · Unread post by **Xaccers** » 08 Jun 2007, 19:20

My old rear pads had warn away at about a 30 degree angle (they weren't sitting properly so the outer edge wasn't wearing making them look brand new!) which also wore the disc down at an angle.

BrianA · Unread post by **BrianA** » 08 Jun 2007, 19:43

Cheers you two,I'm at work at the moment but when I think back I'm pretty sure that my rear pads were worn a bit strange.
Is it just a case of rooting the rust out with a thin piece of metal,smacking it with an imperial size hammer and chisel or a wire brush.
I hope I don't have to split the damn calipers!!!!!

Thanks again.
Bri.

Stewart(oily) · Unread post by **Stewart(oily)** » 08 Jun 2007, 19:54

remove the throughbolts (carefully) and be amazed at the strange stuff that drops out, if your careful a paint scraper or similar will remove deposits without much further dismantling, plenty of grease on the bolts and the mating faces when reassembling, its worth removing the disc and cleaning the rear face/hub too.
Stewart

marsalek · Unread post by **marsalek** » 08 Jun 2007, 20:18

Guys, you can also change the calipers, I mean left vs. right. Thay way you get clean plane that sits on the arm.

Karel

AndersDK · Unread post by **AndersDK** » 08 Jun 2007, 20:34

marsalek wrote:Guys, you can also change the calipers, I mean left vs. right. Thay way you get clean plane that sits on the arm.

Karel

Thats absolutely correct.
Provided the bleed screws will move. They can be a pain to move.

I'd say a large file should be used to even out the surfaces down to solid material. There is no problem if you lose some material offsetting the complete caliper on the arm, as this can easily be corrected by a shim (even 2 shims) made of galvanised sheeting. Even the sheeting from a cut up Coca cola can will do nicely

The object is to get the caliper a square and parallel fit to the arm.

Please note that the small disc retaining screws MUST not be tighten up. Their only purpose is to retain the discs in place until the wheels are bolted on.
If torqued the retaining screws may even cause wobbling discs during drive.

weety · Unread post by **weety** » 08 Jun 2007, 21:45

Stewart(oily) wrote:remove the throughbolts (carefully) and be amazed at the strange stuff that drops out, if your careful a paint scraper or similar will remove deposits without much further dismantling, plenty of grease on the bolts and the mating faces when reassembling, its worth removing the disc and cleaning the rear face/hub too.
Stewart

be very careful doing this.....they run right through the calliper andout the other side.....first time i didnt realise how long they were and just tried to undo them using a breaker bar

two sheared bolts, a sudden realisation i was in a lot of trouble and hours with a power drill were the reward for my ignorance

BrianA · Unread post by **BrianA** » 09 Jun 2007, 14:16

Cheers you lot.
The brake pads looked like a wedge and the caliper was so skewed it was unbelievable.
After an hour of scraping white oxide stuff off the metal face I put it all back togethewr and the wheel now moves more freely.
However,when I put it all back together I noticed that although the mating faces are clean and flat the disk is still hellishly close to the caliper.
Is this normal or should the disk be dead centre of the caliper?
I think it should get through the MOT this time once I've done the other side.
Oh yeah are the sides of the caliper sort of bevelled so that when viewed from an angle it looks like there is a lump of oxide there?
If you don't understand what I mean I'll try harder.

Bri[/img]

Unread post by **CitroJim** » 10 Jun 2007, 13:04

Bri,

The disc should sit bang in the middle of the caliper slot. I've just been doing mine as my rear pads were low and a bit wedge-like. I find the hardness and amount of corrosion on the caliper face is so hard that it looks like parent metal rather then oxide.

You have got to scrape down until the surface is flat and level again on both the trailing arm and caliper. The caliper MUST be removed completely do do a proper job of it.

Check too your discs. I found mine are warped quite badly

Mine was fitted with estate pads in error

(not by me!) and I wonder if these have helped warp the disc.

BrianA · Unread post by **BrianA** » 10 Jun 2007, 13:43

@citrojim,you're absolutely right!!!!
The funny thing is is that while you were making your post I was just finishing off re-doing both sides.
The deposit should be called caliper plaque it was 3-4 mil thick and it was more like a hammer and chisel job than a paint/wallpaper scraper one.
Anyway both disks are dead centre now and both wheels are free.
One of the disks is ever so slightly warped but I'll take the risk with the mot tester and replace in the future.
Now I got a parking light headlamp bulb to replace and stop the ever so tiny height corrector leak on the flared pipes as the mot tester claimed that my brakes were faulty because I had a leak on my brake compensator!!!!!!
Hope you got yours sorted mate.
Bri

fastandfurryous · Unread post by **fastandfurryous** » 10 Jun 2007, 13:47

BrianA wrote:the mot tester claimed that my brakes were faulty because I had a leak on my brake compensator!!!!!!

Oh dear. Did he try to test the handbrake with the rear wheels in the rollers too?

I'd be inclined to find another MOT centre... one that actually understands what they're doing might be good!