[zid]

Help, I need advice....

Just got my car back after having the rear brake caliper on the drivers side serviced. It seemed to pushing the pads on slightly, not enough to slow the car, but enough to hear a metallic grinding (barely audible) whilst driving. This resulted in the wheel getting pretty hot after my high speed jaunts.
My mechanic, who is reliable says the caliper is OK, the pads are OK and I don't feel anything come back through the pedal (warped disc ??).
What could it be???
I've lost 3 centre caps from my Kahns so far 'cos the're melting and at £5 + VAT a piece, this is got to be cured.

Hope someone can tell me what to do/check.

Thanks

Marlon

 

[Chris]

Sounds like sticky brakes all right.
After a 'jaunt' try jacking a wheel up and taking off the handbrake. Spin the wheel by hand and see if it is free. You will soon see if the brake is dragging on the disk.

As it sounds like the brake is sticking then either the caliper piston is not screwed back completely or the handbrake is too tight. You can always loosen the handbrake a little (nut under the handbrake lever) if it is full on after less than 3 clicks and check again. You could also check that the handbrake cable return springs in the caliper are not stuck or fouling on anything. If the piston is not fully screwed back then take the car back to the mechanic and get him to do it again. Failing all of that - take the car back anyway! It wasn`t broken before the service!

Final thought is are you using Alfa or pattern parts as the tolerances may be just out a little on brand new pattern.

 

[zid]

Hi chris
Thanks for the reply. I've done my mechanic an injustice, the caliper was "dodgy" before he worked on it (he was having an attempt at sorting it). He has improved it as the scraping noise is much less after his work. The handbrake etc is all OK. The pads, don't know the make, but the brake was OK when I bought the car. How do you tighten the piston ??? Is it just a case of screwing it in ???
There is a score on this disc aswell, although they were replaced November last year (got the receipt from the last owner)

Marlon

 

[jimybob]

the best way to adjust the rear brakes is as follows..undo the two bolts that hold the caliper on,disconect the h/brake cable and slacken off the adjuster(very important)then you must push and screw at the same time(light pressure should do it)the piston until its all the way back,clean up all the pads and the carrier until the pads are an easy fit (ie loose) put it back together pump out the piston THEN reconnect the h/brake cable adjust it until 4 clicks locks the wheel that should be it..if the problem comes back the caliper will need striping cleaning and new seals.

 

[Chris]

See also www.alf155.co.uk under the tech info section. Details here of how to change your rear brakes with hints and tips from someone who did it (ME )

 

[zid]

Did the rear calipers today. I pushed the piston far out by pumping the handrake lever. One piston was nice and shiny, the other had bits of light rust. I polished the rusty piston with a fine emery board (hope my wife doesn't do her nails soon) so not to scratch the surface. Then greased it up with a high temp white brake grease (95 pence from a motor factor). Slid it all back together and it worked fine . So after my rear caliper success, I decided to do the fronts aswell. They are now smooth and shiny aswell. I then bled the brakes and replaced the fluid with Castrol synthetic Dot 4. What a difference after the work !!!! The car pulls up really, almost too quickly. It's great.

One thing I have to ask....the front discs were not bolted to the hub, just held in place by the wheel nuts. It looked as though the original bolts/alignment studs had been cut down to allow fitment of after market alloys.

Everything is fine and moves smoothly, but I found this a little strange.

Marlon

 

[wrinx]

Ha! Guess what, my V6 failed its MOT today on the rear brake efficiency No prizes for guessing why, good old rear calipers siezed I reckon, any other ideas???

Discs not bolted to the hub??????? Jimybob??

wrinx

 

[zid]

Hi wrinx
Sorry to hear about the MOT.
Before spending lots of dosh on rear calipers, have a go at them like I did. I'v always been scared of calipers, but as long as you don't pop the piston right out, you could have both rears done in about 2 hours. This is the first time I've attempted "proper" brake work and it isn't too bad.
Try bleeding the brakes before you do any work. You never know. Did my wifes car about 6 months ago, her brakes seemed to be fine, but when I bled them, loads of air came out the lines. This had not shown up as a spongy pedal or anything. Needless to say, her car is now a bit safer to drive.

Marlon

 

[richard a]

i have just had the rear calipers replaced on my 155, the bleed nipples on both had been snapped off (one before i had the car , and i snapped the other)
one important thing to look at is the condition of the slides that the caliper 'floats' on. if the rubbers have perished then allsorts of crap can get into the slide and it will seize.
The only way i could get the 'pin' out was to remove the caliper, then unbolt the carrier and place it in a vice , then i heated the area around the 'pin' with a blow lamp. After about 5 mins the 'pin' came lose and i could remove it.I then cleaned out the hole and pin with sandpaper , relubed it, put on a new rubber.
Once on the car the brakes were ssooooooooo much better and the feel of the pedal was firmer.
As a result I stripped all four calipers in the same way, all four had at least one 'pin' seized or very stiff .
I have also fitted steel braded hoses while the brakes were stripped, £52 for a 6 hose set.

 

[marlon]

It feels good when you try something and it works !!!
The rubbers on my calipers are needing replaced. Better do that before they seize again.

Marlon

 

[Chris]

Is there nothing to be done with a caliper with a broken/seized bleed nipple ( I have to be careful with my language here otherwise wrinx will add some pervy comment )?

I have a seized nipple on the front o/s and dont want to go for a whole caliper if I can help it.

Any ideas on how to get the little sod out?

 

[jimybob]

it is possible to drill out the old one but its not easy and rarely works you can drill out to the next size up and then re-tap it but when your paying a garage £38 hour it soon costs just as much as a recon caliper.

 

[wrinx]

Chris

Pervy comments? Me? Sure I don't know what you mean wink

Best go check me nipples...........

wrinx

 

[richard a]

both nipples on the rear calipers were snapped on my 155 . I tried to remove them myself with no success so i got 2 new calipers from Brakes Int. I ordered them at 4.30pm, they were with me at 12 the following day.£59 each, fronts are £44 each.
Great service , and very helpfull on the phone.

Brakes International
tel : 01706 666999

 

[marlon]

Alfa want about £180 each for the rears !!!
Everyone should take a note of the above number !!!
Cheers Richard

Marlon

 

[Chris]

Wow! Thats a good price. I can afford to buy new now, Alfa price was crippling...

However, after reading the horror story that is brake bleeding in the manual I`m a bit nervous. The manual goes into great length about bleeding the abs system after it has got air into it (as it surley will if I remove a caliper) with lots of warnings IN CAPITALS NO LESS and with daft bleeding regimes (including detailing a car with two right front wheels!!??). This is all very worrying. I am now considering getting a blowtorch to the nipple to see it that will persuade it.

 

[wrinx]

More advice from the experienced amongst you required!

I dismantled my rear brakes today, the handbrake on the nearside has stopped working completely, I can turn the wheel with the handbrake on.

One of the sliders was a bit rusty but reasonable, cleaned rsut off and relubed it.

Whilst it was all of I pressed the brake pedal (engine off) but the piston didnt move a bit.

Presume I've got a seized piston.

Any comments?

wrinx

 

[jimybob]

if the piston doesnt move when you pull the hand brake then it is seized.take it all to bits pull out the piston and clean it and the inside of the piston housing with wet'n'dry till it gleams that should do it.

 

[wrinx]

thanks for confirming that Jimybob, guess 'll have to do it all again tomorrow.

wrinx

 

[wrinx]

Pulled the caliper off again and pumped the piston out about 20mm, it was lovely and shiny. Regreased it and moved it in and out a few times just to make sure. Put it back together and it still doesn't work. There is no braking to the wheel either but it does move

Any other tips or is it new caliper time

wrinx