# 85 scirocco brake upgrade to 87 16v 10.1's & rear disc



## VWsEatRice (Jan 13, 2004)

Got the front calipers,rotors,and pads.Will the calipers bolt right up or do I need a different steering knuckle?








Also about the rear, I got the whole rear axle so I know that will fit but the proportioning valve , is there only 1? If so which wheel does it go
to ? It all came off a 87 scirocco 16v.
1 more question, master cylinder, 22mm I know but what other models mc will work?








Thanks for any help http://****************.com/smile/emthup.gif


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## Racer_X (Jul 14, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*


_Quote, originally posted by *VWsEatRice* »_Got the front calipers,rotors,and pads.Will the calipers bolt right up or do I need a different steering knuckle?









The caliper carriers for the 10.1" fronts (from a 16V Scirocco) will bolt right up to your suspension. You need the carriers for the Girling 54 calipers, though. The Kelsey-Hayes carriers for the calipers with the 9.4" rotors won't work.

_Quote, originally posted by *VWsEatRice* »_Also about the rear, I got the whole rear axle so I know that will fit but the proportioning valve , is there only 1? If so which wheel does it go
to ? It all came off a 87 scirocco 16v.

There are two proportioning valves on a 16V Scirocco. Both are screwed into the master cylinder ports. One is inline with the left rear brake, one is inline with the right rear brake. 

_Quote, originally posted by *VWsEatRice* »_1 more question, master cylinder, 22mm I know but what other models mc will work?








Thanks for any help http://****************.com/smile/emthup.gif









*If you currently have the 4 port master cylinder with the ports angled up slightly, and the brakelight switch on the pedal cluster inside* then any 22mm master cylinder will work. The Corrado and A3 Golf/Jetta unit is generally cheaper than the 16V $cirocco one. If you have the older 6 port master cylinder with the brake light switches screwed into the extra ports, you'll need a booster from a late 1985 or later Scirocco or Cabriolet. The change was about mid way in the 1985 model year. If yours has the donut spare, you should have the newer booster and master cylinder.


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## VWsEatRice (Jan 13, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (Racer_X)*

thanks for the advice








any ideas where to get another proportioning valve?








I 'll try the dealer in the morning.


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## VWsEatRice (Jan 13, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*

Went to dealer, he calls it a brake pressure regulator(pressure sensitive) part #b 533 612 151 A
I have 1 already but no part # on it, his diagram showed it installed directly to m/c the one I got was a foot or so downline.
I just want to be sure it is right part b4 i lay down $87
Also does it matter where inline I install it?
thanx in advance 4 any help


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## VWsEatRice (Jan 13, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*

Also if you have any more cost effective ideas let me know!
Thanx


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## Racer_X (Jul 14, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*


_Quote, originally posted by *VWsEatRice* »_Went to dealer, he calls it a brake pressure regulator(pressure sensitive) part #b 533 612 151 A
I have 1 already but no part # on it, his diagram showed it installed directly to m/c the one I got was a foot or so downline.
I just want to be sure it is right part b4 i lay down $87
Also does it matter where inline I install it?
thanx in advance 4 any help









Is the one you have made of two separate pieces? One piece is shorter, about 17mm hex section, and the other piece is a longer 17mm hex section with a short round section on the end? If that's what you have, then that isn't a proportioning valve at all. That's a residual pressure valve. You don't want any of those in your rear brake lines for the disc brakes. If that's there (and it's working right) then it will cause the caliper to drag.
You either need 2 of the 16V Scirocco valves to put into the master cylinder inline with the rear brakes, or you need to mount one of the load sensing pressure regulator's from an A2 car. The load sensing one is cheaper overall, and more adjustable, but it involves fabricating some bracketry to install it. I've never looked to see if the Scirocco floorpan has the mounting tabs for a load sensing regulator. The A1 Rabbits and Jettas seem to all have the mounting tabs, and I have fabricated brackets to hold the A2 GTI load sensing regulator on those cars. The A2 regulator is VW part number 191 612 151C for rear disc brakes (191 612 151 is for drum brakes). Aftermarket places have the regulator for less money than you were quoted for just one $cirocco 16V prop valve.


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## VWsEatRice (Jan 13, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (Racer_X)*

thanx 4 the info








ill look into the a2 setup http://****************.com/smile/emthup.gif


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## VWsEatRice (Jan 13, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*

any ideas on a good source for the aftermarket load sensing pressure regulator?







I had an instant message from [email protected] for 2 prop. valves for $50 shipped. When I IM ed him back w/address and phone # request he doesn't respond.


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## Racer_X (Jul 14, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*

Check Adirondack (http://germanautoparts.com) and Potterman (http://parts4vws.com). Get the one for a 1985-1992 GTI with rear discs.
Or grab one from a parts yard. You'll need the spring, too, and that might be harder to get from a new parts source.


_Modified by Racer_X at 1:04 PM 6-15-2004_


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## OhioBenz (Dec 6, 2001)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*

i got my last set on e-bay for $20
but I'm going to look into th A2 bias unit connection on my GTI so I an adjust my bias!!


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## mk1rocco16v (May 31, 2004)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (OhioBenz)*

Mike, remember the rear axle I gave you with the brakes is bent. You have to take the brakes off it and transplant them to your axle. they are the same though, so no worries.


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## GTIspirit (Dec 13, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (VWsEatRice)*


_Quote, originally posted by *VWsEatRice* »_any ideas on a good source for the aftermarket load sensing pressure regulator?







I had an instant message from [email protected] for 2 prop. valves for $50 shipped. When I IM ed him back w/address and phone # request he doesn't respond.

















Courtesy of _Carmadillo_, this VW load sensing brake pressure regulator should be more cost effective than two separate prop vavles. You just have to figure out how to mount it, which is why I haven't installed mine yet because I want it cockpit adjustable. I'm thinking if mounting it on the exhaust hump right behind the handbrake so I just reach back and twist a dial to adjust it.


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## Racer_X (Jul 14, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (GTIspirit)*

Those are the load sensing brake pressure regulators from the later cars. The *disc brake specific* versions of those can be used with rear discs, even on the A1 cars. Some fabrication is needed to install them. 
They work better installed as intended and connected to the rear suspension. If you understand how they work, you can make them do just about anything and compensate for almost any brake/suspension modifications. If you understand how they work, you can also make a driver adjustable setup for them. Setting them up that way is more difficult than you might think. You have to fully understand the operation of those regulators in order to make them work as a driver adjustable part. 
It's also very easy to install them as "driver adjustable" valves and make them completely non-functional. (Hint, there's an additional part that's critical to the operation of the regulator that isn't in your picture.)
Personally, I prefer to use them in their normal load sensing operation (mounted to the front of the suspension) on the A1 cars that I've put rear discs on. 
I've also used them on various race cars I've set up over the years. On those, I've had the best results with them installed and attached to the suspension with brackets that are modified to compensate for the lower and stiffer race suspension and to provide greater adjustability for conditions. That way you really only need to make adjustments during practice/qualifying to match the balance of the car and the relative grip of the track surface. The car makes its own adjustments for fuel load (I like running longer "endurance" races with my car). I have also set them up as driver adjustable units and they work well that way, but that's not as convenient/easy as the suspension mounted setup. The ultimate would be a suspension mounted setup that had some driver adjustability features as well.


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## GTIspirit (Dec 13, 2002)

*Re: 85 scirocco brake upgrade to 87 16v 10.1's & rear disc (Racer_X)*


_Quote, originally posted by *Racer_X* »_Those are the load sensing brake pressure regulators from the later cars. The *disc brake specific* versions of those can be used with rear discs, even on the A1 cars. Some fabrication is needed to install them. 
It's also very easy to install them as "driver adjustable" valves and make them completely non-functional. (Hint, there's an additional part that's critical to the operation of the regulator that isn't in your picture.)


Well, I believe it was my former 1984 Jetta diesel that had one of these in the drum version, but my 1984 Rabbit GTI doesn't have this, and my 1987 Golf GTI does. Searching on these vehicles will get you the drum or disk version.
Not sure what piece you mean by the hint, of course you can't just bolt it down and plumb the lines. That would be some pretty funky brake bias with that lever flapping in the breeze.







Mine, yet to be installed, is rigged with a balljoint on the lever then a threaded rod that will pull the lever in and out, which is where the adjustment comes from, right? Or am I completely off base here and missing something?


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## mk1rocco16v (May 31, 2004)

I don't think Mike needs those things. What he was talking about are the little cylinder things on the brake lines near the master cylinder that requlate the difference in line length to assure that each brake gets equal pressure.


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## GTIspirit (Dec 13, 2002)

*Re: (mk1rocco16v)*


_Quote, originally posted by *mk1rocco16v* »_I don't think Mike needs those things. What he was talking about are the little cylinder things on the brake lines near the master cylinder that requlate the difference in line length to assure that each brake gets equal pressure.

You mean difference in line length front to rear, or rear left to rear right?


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