Alfa Romeo Owners Club of Australia Forum

Technical => 105/115 Series (105 Coupe/Spider/Berlina) => Topic started by: berlinaman on May 15, 2010, 08:48:21 PM

Title: 1750 berlina (twin servo) brakes feel less than great
Post by: berlinaman on May 15, 2010, 08:48:21 PM
Hi all.

Anyone had experience with tired brakes. Mine feel a bit notchy and stick on a little after releasing the peddle when coming to a stop and have at times remained slightly stuck on untill a firm jab of the peddle. The peddle also feels lose,like it is moving the clutch peddle a bit, even though Bruno (at Maranelo Motors) assures me it is OK. He cannot feel the sticking (of course it never happens when at the shop) and has overhauled the rear calipers which did nothing to improve the feel.

Could it be the servo's or the master cylinder or is there some other item to look at. What are the costs to replace/rebuild these items and can I expect the brakes to feel like new again as that is what I would like.

Any advice would be much appreciated.

cheers

Tony
Title: Re: 1750 berlina (twin servo) brakes feel less than great
Post by: cjheath on May 15, 2010, 11:39:07 PM
Quote from: berlinaman on May 15, 2010, 08:48:21 PM
Mine feel a bit notchy and stick on a little after releasing the peddle

I reckon you have problems with the master cylinder; it needs new seals. That's my guess anyhow.

Quote from: berlinaman on May 15, 2010, 08:48:21 PM
The peddle also feels lose,like it is moving the clutch peddle a bit, even though Bruno (at Maranelo Motors) assures me it is OK.

They all do that, it's due to the pivot moving arrangement. I've thought about trying to fix it, but Bruno is right, it's not a problem.
Title: Re: 1750 berlina (twin servo) brakes feel less than great
Post by: 1750GTV on May 16, 2010, 08:54:51 PM
The rear proportioning valve can cause similar problems if it plays up. These can be repaired, but it is probably easier to just replace it with a newer type. If you replace it, you'll have to reroute some of the brake piping. Probably best left to a hydraulic shop unless you have the right gear.

As to the loose pedal feeling, components of the pedal box in the floor mounted pedal system wear over time. The clevis pins (2160.17599 in the photo) and the holes where the pins go through both wear. The clevis pins can be easily remade and can be fitted without removing the pedal box. Wear in the pedal ends themselves is more difficult to fix as the holes wear into an ellipse and the pedal box would have to be removed and disassembled so the holes could be redrilled. Oversized clevis pins would then have to be fitted.

Most people just tolerate a bit of movement in the pedals.

Chris
Title: Re: 1750 berlina (twin servo) brakes feel less than great
Post by: berlinaman on May 17, 2010, 05:47:34 PM
Thanks guys, that's really usefull info. I think I will start by having the master cylinder reconditioned and look at the peddle linkages. Failing any improvement then I'll address the other bits.
cheers
Tony
Title: Re: 1750 berlina (twin servo) brakes feel less than great
Post by: blacklotus99 on May 22, 2010, 07:02:52 PM

If you are having the issue of when coming to a stop the brakes bind when stopped and then release, its the boosters.  Have the exact same problem on my car.  Probably a leaking diaphragm in one or both of the boosters.  That is not a M/C issue.

You can have them rebuilt but its pricey, about $3-400 a booster I think, your mech should be able to tell you.  Can also get them on exchange.  Depending on what you are using the car for it may be worth considering a booster delete, you dont really need them.  Check the threads on alfabb for info.

Sounds like pedal linkages need fixing too.  Check the pedal box carefully and get it rebuilt if necessary, safety issue there.