Alfa Romeo Owners Club of Australia Forum

Technical => 932 Series (156, GTV, Spider, 147, GT, and 166) => Topic started by: Cool Jesus on December 02, 2013, 09:34:02 AM

Title: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 02, 2013, 09:34:02 AM
Hey troops, just posting this up to see if someone can clue me in on the functions of these rear handbrake caliper set ups.
I'm currently refurbishing a complete set of brake calipers for the 147, but I also recal seeing the same set up in my spider. The rear brake caliper has a winding mechanism for the handbrake to come on. Having pulled apart the 147 calipers it's just activated on a worm screw inside the caliper which uses the handbrake cable rather than fluid pressure. The workshop manual for the spider only refers to it when new pads are being fitted. In that you wind it back in to allow the new pads to be fitted (being thicker). I'm assuming its a self adjusting set up.
My question is, is my assumption correct, the only time it needs to be wound, is when new pads are to be fitted. Only to then pump the peddle and handbrake to have it adjust itself?
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 02, 2013, 09:07:10 PM
You need a caliper wind back tool kit, i purchased a cheap caliper wind back 'cube' for about $20 and it didn't work, as the various 'pins' on the 'cube' didn't quite match the *LUCAS* caliper piston, ended up buying a professional kit with all the different pin combinations that i needed, they are cheap enough on ebay, mine worked a treat.
As the pads wear, the pistons winds in and leaves a gap of about ,1mm, just like in a Alfasud..........except it works.
*LUCAS*, i cannot beleive something made by Lucas actually works this good!, the Lucas motto is "Get home before dark".
The handbrakes must have by law a solid mechanism, the fronts don't have adjusters, they work by the fluid taking up any slack due to wear.
The adjustment on the cable is to take up any stretch in the cables, but you always back them off, when putting in new brake pads, then you adjust the cables, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 02, 2013, 10:02:36 PM
BWAH hah, Lucas, at least someone has a worse wrap than Alfa.
Thanks col, have been eyeing off those brake kits.
I'm still confused though. I'm ok with the hand brake cable, no issue there. Just, is the rear piston wound back into the calliper to only facilitate the renewal of the pads? Once installed does the calliper then adjusts itself by operating the foot pedal? Of course pumping it up before driving off anywhere.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 02, 2013, 10:24:55 PM
You have to wind back the piston, to allow the thicker pads to go back in, then the adjusters keep the disc to pad clearance adjusted, i purchased the kit off ebay that had a reference to Fiat /Alfa Romeo, but i would go to a Auto parts placed, with the pin centres measured off your pistons to get the correct ones, i got the correct ones through sheer luck.
LUCAS stuff isn't too bad.....did you know Lucas invented the worlds first intermitten wiper?, beat that Magnetti Marrelli!, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 03, 2013, 12:15:00 AM
Excellent, makes sense now. Didn't realise pad choice was so particular, I'll have to pay close attention to it then. Might even toy with having these rear callipers retro fitted to the Alfetta. The self adjustment is very appealing compared to the old requirement of constant adjustment with the older version. I wonder how offensive this would be to the purist Alfisti if I upgraded the rear brakes?
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 03, 2013, 04:14:58 PM
Throwing away those rubbish German ATE calipers that don't work, for some British Lucas calipers that do, makes good sense to me, wish i had the Lucas calipers when i was spannering the Sud, wouldn't have rolled down the hill 3 times, LUCAS was the inventor of the worlds self dimming headlight, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 04, 2013, 08:08:24 PM
For my LUCAS rear caliper, the 2 pins are 6 mm diameter on 32 mm centres, this is a LUCAS caliper on a 156 JTS, a Spider may be different, LUCAS diversified in the 70's and started manufacturing other products such as brake parts and consumer goods, they had a line of domestic goods including vacumn cleaners and it was the only LUCAS product that didn't suck, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 05, 2013, 07:51:58 AM
Well, I've done a quick mock up with the spare 147 Lucas caliper on a bare Alfetta transaxle and it looks like it will work with a mounting bracket! I'm definitely placing it on my todo list for the Alfetta build, hell I may even be able to mount them a little furthe towards the lower rear for even better maintenance access. Unless I just haven't come across it yet on the web, I'm surprised that anybody hasn't yet attempted a better set up for the rear brakes on the Alfetta. Although there's just been a post written about a better set up for a track Alfetta, still access is an issue though.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 05, 2013, 08:35:40 PM
The ATE is a two piston type, i cannot remember if the LUCAS is a two piston or floating caliper, the floating caliper would be a bit more spongy with longer travel on the pedal, but the pad area i think is bigger, you would have to rig up a two cable handbrake system on the LUCAS, as opposed to the one cable system on the ATE, may be best to run the handbrake assembly off the 147 and shorten the cables, thats if you still want to run a handbrake.
Little known fact about the British, is that they drink warm beer because they have LUCAS refrigerators, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 05, 2013, 10:05:16 PM
That's what I was thinking with the handbrake setup, have the bits for it lying around. Should be relatively easy to do, particularly as nothing is moving around due to the transaxle. A spongy pedal, hmmm. Is that a floating calliper characteristic (yes the Lucas is a one piston floater)?
Will changing the brake booster help? I also have the booster for the 147. I'll obviously need to do my homework on this brake setup, especially as it's for a road registered vehicle carrying family  actually would this need engineering certificates?
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 06, 2013, 08:36:06 PM
With floating calipers, they are 'loose', and that pulls the brake pad off the disc, when you push the brake pedal the caliper pushes the pad against the disc, and between the caliper being loose and tensioned up, you are using a bit of brake travel, buts its nothing to worry about, the main thing is that the LUCAS caliper will have a better handbrake than the ATE, in my opinion anyway.
Changing the brake booster won't help, it will only increase or decrease the effort by the driver when braking, dependig on booster size.
You would need engineering certificates,......but how many roadworthy people would know the LUCAS caliper has been substituted for an ATE, they pull the handbake on and the LUCAS handbrake locks, unless you tell em about the LUCAS conversion.
LUCAS tried to sell engine computers to Rover, but failed the quality standards, when they couldn't get them to leak enough oil, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Cool Jesus on December 07, 2013, 09:10:41 PM
I hear ya col, never had an issue with RWCs. I'm just mindful of insurance and heaven forbid, should the Alfetta come acroppa, they'll deny any claim if they notice the change without proper papers or notice. Anyhow, I'll look at it more closely when overact this facet of the restoration.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: colcol on December 07, 2013, 09:25:46 PM
We had this problem with a Alfasud, the crappy ATE calipers never had a working handbrake, because the adjusters wouldn't adjust the lash to the correct amount, so we put a hydraulic handbrake that worked a treat for 26 years, the only problem was that it was illegal, because the ADR's say that the handbrake must be of a mechanic actuation, not hydraulic as it could leak and cause the car to roll away, which it did with the ATE, if those good LUCAS calipers off 147's were around in 1985, they would have been fitted to the Sud.
The only downside to the LUCAS calipers is that you need a piston windback tool to put new brake pads in the LUCAS caliper, a small price to pay for a handbrake, LUCAS made the worlds 3 position headlight switch, DIM, FLICKER and OFF, Colin.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 04:10:45 PM
Old post but I'm in the process of changing rear pads on my 147.
Invested in a decent position wind back kit but I can't get the piston wound back more than about one turn.
Could the position be seized?
Do I need to detach the handbrake cable?
Do I need to loosen the brake bleed screw to release pressure as I wind back?

Any other tips?


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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: bazzbazz on March 17, 2019, 06:35:40 PM
No need to remove hand brake cables, just make sure the hand brake is fully released.

No need to undo bleed nipple, BUT, you do need to remove the Brake Fluid Reservoir cap and a small amount of fluid. Removing the fluid prevents the reservoir from overflowing as you wind the piston back in, and removing the cap prevents pressure from building up, which could be whats causing your problem.

Other than that, your ARE rotating them clockwise . . . . .aren't you?   ???

;)

Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 07:00:42 PM
I think your question has given me the answer!
So the piston must need to be wound in, not just pushed in?
So I must need to select the right plate from the brake calliper kit that has lugs that match the face of the piston?
I was trying with a flat plate and that was getting me nowhere.
And both callipers are RH? The kit I bought has a RH and LH tool.

Thanks for the advice!



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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 07:18:54 PM
(https://uploads.tapatalk-cdn.com/20190317/95615c8991ffe38e8c156013b0c31301.jpg)(https://uploads.tapatalk-cdn.com/20190317/2e6dbe376e8816258baac169e44179ab.jpg)(https://uploads.tapatalk-cdn.com/20190317/b720e274aa90b53329cc64916d84ee7f.jpg)


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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: giulia_veloce on March 17, 2019, 07:42:10 PM
Off and On topic

Above it was mentioned that the Alfa Sud  inboard front Brake adjusters and Alfetta Rear Inboard brake adjusters dont self adjust .
I had this problem in the mid 80s and found a solution.
If the calipers are in good usable working condition,there is a cure.
Did it to all my customers cars that mentioned the problem.
All were extremely happy with the result.
Only time they needed adjusting was when the brake pads were changed.
And yes,,adjusted when new pads fitted,,but never in between
The ONLY unhappy people were the ones who did not believe me and said there is no cure and could not be done.

I used to laugh at the time,,that some Alfa owners paid $1000 for a reconditioned pair of calipers that was guaranteed to self adjust.They did not.

So,,to my good friend Cool Jesus,,,you can do it the easy way and use your original inboard rear calipers on your Alfetta,,or change and re-engineer the handbrake system with the 147 system you mentioned.


Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: giulia_veloce on March 17, 2019, 07:57:38 PM
Hi Campbeli

The way I do it

Slacken handbrake cable from handbrake lever so the handbrake cables can be removed from calipers.
Remove caliper,,but NOT hydraulic hose.
Unscrew fluid cap at reservoir and remove some fluid,,as winding in the caliper piston will raise the reservoir fluid level.
I mount the caliper the the suspension strut via a nut and bolt i keep in the kit.
The reason for this is so i have an extra hand to wind the caliper piston in and adjust the tool while winding the piston in clockwise.
Hopefully you will find the hole tab in the strut to secure the caliper via 1 caliper mount.
PM me if you dont understand and will explain ot over the phone.
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 07:58:28 PM
Is that how you fixed the hand brake in my sud in the mid the late 80's ?




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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: giulia_veloce on March 17, 2019, 08:02:00 PM
well Campbeli

maybe I did yours
did it work as it should ?
After I did the cure ?
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 08:02:55 PM
100%


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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 08:08:29 PM
Good advice, thanks QV! I'll have another crack at it. Might need to call for some 105 parts soon anyway.


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Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: giulia_veloce on March 17, 2019, 08:11:14 PM
campbeli,,i sent you a PM to explain it better= 147 piston retraction easier method
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: bazzbazz on March 17, 2019, 09:02:25 PM
https://www.alfaworkshop.co.uk/alfa_rear_brake.shtml (https://www.alfaworkshop.co.uk/alfa_rear_brake.shtml)
Title: Re: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 17, 2019, 09:11:24 PM
Thanks
Also looked at https://youtu.be/WbzEOIlkOgQ
Pads and discs in less the 10 min! So easy?


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Title: Rear brake caliper wind up mechanism/handbrake
Post by: Campbeli on March 24, 2019, 11:28:22 AM
Making good progress (I think), thanks to all the good advice.
New pads are in and slid pins re-greased.
The RHS top pin was stuck, which explains the uneven pad wear.

Can anyone tell me why the top pin has a thicker section than the bottom pin and does not move in and out as easily? The thicker pin was the one that had seized.

New pads are rubbing on the disc  (not due to handbrake) so I guess that will resolve itself during the bedding in period.
(https://uploads.tapatalk-cdn.com/20190324/9feca4a239ecbbaa3329bcfb803accab.jpg)


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