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Discussion Starter #1
My old rear calipers are giving me 'gip. :D Not content with being completely rebuilt, with new sliding pins, hoses, pads etc. they completely refuse to grip the discs.

MOT man is taking a very dim view of them, yet the discs are showing that the pads are sweeping the whole disc face.. just presumably not with enough force. The reading was 18% or something. Sounds poxy but the brakes actually feel okay, if that makes sense. Handbrake is good too.

I set the brake bias valve to "max" rearwards and it helped a bit but I don't know what else there is to try. The cylinder moves in and out quite freely, though I didn't take that out of the caliper body itself.

Anyone got any tips, before I start looking at a new balance valve and/or, God forbid, new calipers....? :eek: :eek:


Ralf S.
 
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Does the Bias spring on 155's not reside underneath on 155's and get all gunged up and corroded (seem to remember someone saying it's a good idea to replace this at some point)

John
 

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Discussion Starter #3
The beast has a heavy duty spring on it and I set the adjuster to "max".


Ralf S.
 
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Is the piston moving freely? When was the fluid last changed? Re-bleed the system.

wrinx
 

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Alfa Romeo 156 JTD 8v Veloce (2005)
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I know this one... been through it all myself over the last month or so. I was advised at the last MOT that the pipes into and out of the regulator valve were getting a bit rough so replaced them all. I found that the valve 'airlocked' so took several attempts at bleeding. Basically I used a second person to stamp several times on the brake pedal, then hold it down to bleed the calipers forcing the air out of the valve. Did that a few times, drive around a bit then do it again and certainly noticed a difference.
On the brake testing machine the rear brakes were giving enough force but the drivers side was not good enough on the handbrake. A new cable did the job on that side as it had gathered damp inside and became sticky - it got in where the cable sits on the caliper. Made sure I lubricated the cable well and it now seems fine, also smeared grease to prevent damp getting in again.
Hope this helps!
 

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Discussion Starter #6
wrinx said:
Is the piston moving freely? When was the fluid last changed? Re-bleed the system.

wrinx

Looks good to me. Wound it in with me winding tool and they were pretty "loose". Fluid is all-new Dorothy 5.1 and the system is as air-free as it's ever been, judging by the firmness of the pedal.

I'll speak to the mechanic and see what he says. If there's any tinkering that can be done with the regulating valve that will at least eliminate the calpers as the problem.

If it's the calipers then I'll have to own up, sell the missus and buy some. I found www.speedways.co.uk offer re-manufactured calipers at half the price of genooine.

Ralf S.
 
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