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I have been experimenting the following problem with my GTV6 rear calipers, I set the vey tight book gap margins between pads and discs (parking brake off), and then set the parking brake to 4 clicks, then I take the car for a ride and it works well for the first 200-300 kms. braking flat etc.. but after it begins to brake very nose heavy.

When I return home the parking brake only works when pointng to the sky and checking the pad vs rotors gaps they are completelly out of the initial settings.

Consulting my local Alfa master mechanic, he says that rear calipers are faulty, interior springs ko? and shoud buy new ones.

BY the way on first hard braking one of the rear calipers gets collapsed making tha car braking slightly sideways :eek: , on later hard brakings does no occur.....

And finally the question, where can I source new brake calipers for my GTV6? which brands? reconditioned ones if good should be fine but as I live in Spain the cost of sending the old ones will make new ones a better option.

Thanks and sorry for the long post
 

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IAP in the US has rebuilt one's for $108 with a $90 (each - returnable) core charge. I assume Highwood in the UK would also have them.

If my car, I'd jack the rear up (placing strong stands under the rear jacking points), back off the handbrake cable, turn each wheel to see if the rotors are warped (you might be able to hold a piece of chalk against the edge of the rotor and then turn, getting a visual idea if each is warped). I'd also take a mirror and flashlight to see if the pads are wearing evenly. Then readjust each caliper by having the pads just barely touching the rotor, then back off just a wee bit. Tighten the lock nut on the outer adjusters, making sure not to change the setting. Don't go crazy on the tightening - just snug. Then readjust the handbrake so it points up at about 45 degrees rather than four clicks. I think you're tightening it so much the rear discs heat up throwing everything off.

I'm assuming the seals on the calipers aren't leaking. If they are, then get rebuilt ones - but use this procedure to adjust them. I'll add that I'm sure the inside caliper adjusting screw's seals get blown out and start leaking when the hand brake is pulled on too forcefully. Also pulling it on hard after a 'spirited' run warps the thin rotors.

Biba
 

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Discussion Starter #3
Thanks dfor the answer Biba69

Then the reason for the pad to rotors gap disarrangement in 300km is the parking brake being to tight (4 clicks) and not faulty calipers?
 

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It sounds like the rear brakes are getting out of adjustment. If your inboard pad clearances are increasing you will need to use some liquid thread lock on the adjuster.
 

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I'm assuming the seals on the calipers aren't leaking. If they are, then get rebuilt ones - but use this procedure to adjust them. I'll add that I'm sure the inside caliper adjusting screw's seals get blown out and start leaking when the hand brake is pulled on too forcefully. Also pulling it on hard after a 'spirited' run warps the thin rotors.

Biba
I'm not sure why recommendation for the rear calipers is to replace them. For such a small simple part it is too much money and hassle. It you pull them off to replace them, then all you need do is pull them apart and any decent brake specialist will match the kits. They are really simple to rebuild and leave a whole lot of money in your wallet. My kits cost Can$30.00 per side. Only problem was the very small "O" ring on the adjuster screw. I matched it up at a parts specialist.

Now if you can only figure out a way to get the parkbrake to stay adjusted without the lever pointing up through the sunroof!!!
 

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Another theory I've heard over here is that the automatic adjustment of the rear calipers can't keep up with heavy brake use (eg. track days, close-to-racing use)? Anyone heard that before?

Cheers
Magnus
 

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I agree with the parking brake too tight, the book says 7 clicks, if you have it too tight, they are getting hot, overheating fluid and wearing the pads, you will have to play with the parking adjustment and the pad clearance, maybe use the widest gap within spec and try it again, this will just give you more pedal travel, but may save rear brakes.
 

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Another theory I've heard over here is that the automatic adjustment of the rear calipers can't keep up with heavy brake use (eg. track days, close-to-racing use)? Anyone heard that before?

Cheers
Magnus
I've had 7 transaxles and never once used them on the track. But most of us on occasion use them on the street in anger, especially when I was younger. In all that time it never takes long for the park brake handle to assume normal position, ie. pointing up through the sunroof. I think it's just a poor design.
 

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I know I'm reviving an old thread, but I have the same issue. I rebuilt the calipers, installed new pads and rotors, replaced brake hoses, made a special adjustment tool etc.

Brake adjustment doesn't last long......
1620236
1620237
 

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I still have the parking brake on my race car. It helps with trailer loading etc. and is just nice to have.
Our races are short 20-30 session so we don’t get the heating issues some get i.e. Lemons racers .
I have not had to adjust the parking brake in several seasons.
 

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Yes, the parkbrake has more travel.
But the root cause is the clearance between the rotors and pads increases bit by bit shortly after adjustment.
 

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Hey SlowCreek
Yes, the parkbrake has more travel.
But the root cause is the clearance between the rotors and pads increases bit by bit shortly after adjustment.
Need more details on this. You say clearance between rotors & pads is increasing. How are you measuring this? With a feeler gauge? What are the actual measurements. Are the inboards pads the problem, or the outboards pads? or both?

What is the history of these calipers, been on the car a long time? or recently installed?

Inquiring minds want to know.
 

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These inboard brakes are a little weird.
On my Alfetta GT, used as a daily driver for 5 years, I didn’t ever have to use the pad adjuster mechanism, only the cable adjuster for cable stretch (and probably only once), the handbrake worked beautifully, holding on good slopes all the while.
Alfa used the same brakes on the front of the Alfasud, and I had to adjust those @ every six months.
Maybe it is all down to pad wear.
Trust the manual.
 

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I rebuilt them when I got the car.
I've adjusted them with feeler gauges, without feeler gauges using the old fashioned way of spinning the wheel.
I've never measured the amount of clearance come readjusting time, but I have to adjust all 4 adjusters to get them back to where they need to be.
The adjustment just doesn't "hold".
I've tried keeping them in adjustment by standing firmly on the brake pedal and cycling the parkbrake handle.
Perhaps adjusting the pad clearance again and then adjusting the parkbrake cable tighter than I have been?
 

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Hey Slowcreek

Well that is a mysterious problem. What effect does it have on brake performance? Do you have to pump the brakes to get decent stopping power?

Could it be brake pad knockback. If the bearing that hold the stub axles inside the transmission are wearing out, that could let the the brake rotor move laterally (side to side) as it rotates. That would push the pistons back into their bores. Ii'm just spitballing here.


Hope this helps
 

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Thanks for the link.
Braking performance is still good. It's better when the rears are first adjusted and the brakes front bias after that.
It stops well.
Both adjusters need adjusting on each caliper. It's not just an inner or outer adjuster.
I've adjusted using feeler gauges, drag method etc. all the same.
I'm thinking of setting them on the tight side and then adjusting the parkbrake up kinda tight....
 

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Glad you liked the link. I re-read your original post and saw that you had replaced the brake rotors. The only thing, that I can think of is too much play in the stub axle bearings. The brake rotor moving side to side would definitely push both inboard & outboard pads back in their bores.

Bye
 

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I THINK I figured it out!!
Have yet to go for a test drive.

I laid under the car and just looked around. The brake lever on the right hand caliper was not pointed out on top as far as the left one. I had to look a few times to see the difference. Only by a slight amount. I pushed that lever over with a pry bar.
Then, I loosened up the parkbrake cable a bunch even though it wasn't tight.
Made sure both levers were seated and adjusted the calipers.
Now, my parkbrake is loose in back. Maybe 1/8" slop in the cable.
3 clicks and the parkbrake holds.....
 
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