Fulvia S1 brake pedal rod adjustment

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lancia7550
Posts: 33
Joined: 10 Nov 2012, 22:26

Fulvia S1 brake pedal rod adjustment

Unread post by lancia7550 »

Hi, the brake pedal on my S1 1.3S Coupe (front servo'd) has always been low, even though brake performance is good. When I recommissioned the car after a 20 year slumber about 14 year ago I had some issues with sticking brakes and a mechanic vary familiar with Fulvias reduced the rod lenght as part of the trouble shooting. It turned out to be the return spring in the master cylinder that got too weak to release once brakes were applied and after replacing the issue went away.

So my question is how do you measure the gap between the tip of the brake rod and the master cylinder piston. I read somewhere that this should be 1mm, is that correct?

I am replacing the rubber brake hoses and would like to get the pedal free play and height right at the same time when bleeding.
Huib
Site Admin
Posts: 1554
Joined: 17 Dec 2008, 10:12

Re: Fulvia S1 brake pedal rod adjustment

Unread post by Huib »

Hello Albert,

Right. The clearance between fully retracted plunger and pin should be around 1 mm, measured between pin and plunger. The accuracy is not very important. If you can feel some clearance when moving the pedal by hand, than it is ok.

Do you have an original Lancia 19 mm master brake cylinder?

The pedal has to be high!!!! This is important. It is a Duplex system which has to work if one of the circuits is empty. You need all the pedal travel you can get to make sure the car will brake with either the rear or the front section out of order. I think everybody should check the brakes of his S1 Fulvia with one and the other of the circuits empty.

If you need help in getting the pedal up, please ask.
lancia7550
Posts: 33
Joined: 10 Nov 2012, 22:26

Re: Fulvia S1 brake pedal rod adjustment

Unread post by lancia7550 »

Thank you for the reply Huib.

Yes, I have the original 19mm cylinder. I have ordered a new one as I have taken mine apart and was not too happy with the condition of the bore.

Once installed and bled I will check that I get the pedal as high as possible while maintaining a small clearance between the rod and piston.
lancia7550
Posts: 33
Joined: 10 Nov 2012, 22:26

Re: Fulvia S1 brake pedal rod adjustment

Unread post by lancia7550 »

Hi,

I have fitted a new master cylinder now and noticed that there is no adjustment possible on the brake rod, only on the stop between the pedal and pedal box, so I will check the play there.

Currently I am missing a return spring on the brake pedal. Is this the same as the clutch return spring so I can use that as a sample?

Thanks
Huib
Site Admin
Posts: 1554
Joined: 17 Dec 2008, 10:12

Re: Fulvia S1 brake pedal rod adjustment

Unread post by Huib »

Correct. Both springs are identical.

Another point while you are at it.

The plastic bushes for the pedals are not as stable as modern plastic. The plastic has absorbed moisture over the years and has expanded. On a hot day they will expand more and the pedal shafts will no longer return.

2 bushes for clutch
2 for brake
1 for throttle

Best replace them and polish the shafts.
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