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[gritsop]

Hi

I will prepare a complete article for the website of www.alfa-restoration.co.uk and you will all see photos etc.

I really dont know about the two versions of bias valves. Once the rear disks have bedded in I will know for sure.

Vented brakes on the front can fit to 13 inch rims. 14 inch rims are required for the rear.

You are right about the piston diameters. Moving more brake fluid is creating this feel. My friends 33 with rear disks and no ABS has the same pedal feel even with steel hoses all around so I will conclude that this is normal.
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Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[Sergio]

Hi,

Have you changed the bias valve yet?
If not... How have the brakes been working?

I need a bias valve for my 33 16v... it's got ABS, and from what I've been told the one indicated for the ABS brakes is unavailable... out of stock and production... So I'm looking for a solution to fix my rear brakes...
It would be really great if the Non abs Version of the bias vale worked on the ABS system...

Any ideas?

All the Best

Sérgio
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Driving a 33 1.7 16v QV & Lancia Musa

[gritsop]

I havent replaced the bias valve as it is out of production.

My garage had it adjusted to a less tight setup and the brakes perform very well compared to the previous setting of the bias valve. The rear used to feel like it is locking and the 33 appeared to be skidding. After the adjustment the rear brakes as it should with no tendency to skid.

To my opinion if your garage knows how to adjust a bias valve then you have no problem either ABS or not. Just keep in mind that the weight needed to adjust the valve is 5.2 kg ... add to that the fact that the spring is now tired after 20+ years so make it ~ 6 kg.

Since the rear disks have greater efficiency compared to drums then the bias valve needs to operate with less tightening than the drums setup

Overall the brakes are just fine. The pedal is a little spongier than on the drums setup but I got used to it after the first couple of kms.
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[Sergio]

Hi,

Thanks for the reply

Now I have to get a new bias valve (normal non-ABS) te replace mine that isn't letting the fluid get past on the rear left wheel... Lots of pressure getting in none out... the other side is fine.

I wonder if I put more weight on the adjuster, that will open more and let the wheel brake like the right wheel?

Does anyone have a schematic of the bias valve or an idea of how to dissasemble one? I still have an old valve that I could try and repair...

Best regards,

Sérgio
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Driving a 33 1.7 16v QV & Lancia Musa

[gritsop]

The only way to cure the problem is by getting a new valve.

The problem is attributed to the fact that the internal seals of the bias valve cant be obtained. Otherwise we could take it apart and replace the internal seals... In addition the bias valve appears to be adjusted from factory regarding the tension it gets. Therefore the only way is to replace it.
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[Sergio]

Thanks for the reply.

All the Best

Sérgio
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Driving a 33 1.7 16v QV & Lancia Musa

[gritsop]

Hi All

Well ... The brakes have now bedded in but I made a nice observation one the rear wheels. Left side showed the well-known black dust from the pads in contrast to the right side which showed almost no dust at all.

On the dry the 33 would brake straight to my surprise as it was clear that the car brakes on the 3 wheels. However on the wet the 33 is pulling to the left.

A quick bleeding on the rear wheels showed no air bubbles ... a visual check on the bias valve showed some moisture on the boot - lifting up the boot and a river of brake fluid spilling on the floor. "Luckily" for me the brake system doesnt have any problem which is correlated with the ABS conversion and a replacement of the bias valve will cure the problem

I know ABS specific bias valves are out of production but after intense searching i managed to find in stock 3 valves under the Bendix brand which are cross-referenced to the 60564894 ABS bias valve.

If any of you guys are interested in an ABS specific valve let me know.

http://www.oscaro.com/regulateur-de-freinage-bendix-312055b-522052-73-p

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_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[Sergio]

Hi,


Have you seen any difference between them?

I've just bought a "normal" one from Alfa Sud Parts... And after reading your post, I'm afraid I did the wrong thing... Still waiting for it to arrive through the post...

Do you think there will be a problem with an Original Alfa "Normal" valve?

All the Best


Sérgio
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Driving a 33 1.7 16v QV & Lancia Musa

[gritsop]

Hi

Since the 33 is not driven regularly, I am waiting for the right side wheel to bed in correctly. Today I made a test on the wet and the 33 brakes in a straight line, so the new bias valve has solved the incorrect braking.

I still need to wait and while and then do an adjustment.

To cut a long way short, Alfa had a specific reason to fit different bias valve compared to the nornal one. I most probably think it is the spring preload inside the valve.
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop