"bleading" Brakes
-
Bryan Dugdale
"bleading" Brakes
i am having problems acheiving a decent pedal on My Fulvia series 2; i rebuilt the master cylinder with new seals, which works fine with the rear brakes disconnected. With the rears plumbed in, the pedal is soft as a babys backside, and occasionally goes flat to the floor!. Checked out the obvious places for leaks, and all seem ok . More than a bit puzzled by this,as i took the master cylinder apart to check the seals were in the right places,and they were.I have used every bleeding technique known to man,so its desperation time. Does anyone have an idea where i should try next?,many thanks,Bryan
-
Bryan Dugdale
Re: "bleading" Brakes
I forgot to say that all the pipes are new,and the balance valve on the rear has been by-passed. Since posting the original messae,I've seen the "solid pedal" correspondence ,could this be a similar issue Huib? thanks,Bryan
-
P. de R. Leclercq
Re: "bleading" Brakes
Quite often th eproblem lies in bleedingt he master cylinder. Our procedure at Evo used to be mounting the master cylinder in the vice and pumping against one's finger until pressure could be felt at the outlets.
Try pumping six times or so quickly and then releasing the bleed nipples and repeat the procedure. Sometimes this will help
Paul
Try pumping six times or so quickly and then releasing the bleed nipples and repeat the procedure. Sometimes this will help
Paul
-
Bryan Dugdale
Re: "bleading" Brakes
Thanks Paul,today i tried pumping the pedal 5 or 6 times,the last stroke went strait to the floor,most worrying. As i pointed out,with the rear outlet blocked,the pedal is firm,could it be an inyternal fault in the cylinder ive missed?,Bryan
-
P. de R. Leclercq
Re: "bleading" Brakes
Well, possibly.
The Fulvia cylinder (S1s are worse) can be troublesome. One common problem is the springs: the thing will not work properly if they are replaced the wrong way round (they are different lengths). I can never remember which way they go, so when I take a cylinder apart I arrange everything in order. I should write this stuff down.
I assume that the cylinder was checked for wear and damage inside? An aluminium cylinder over 30 years old is unlikely to be perfect.
On my own car I gave up after three rebuilds and threw the thing into the dustbin. I now use a FIAT iron one that works beautifully. For S2s with servo, the Peugeot 306 cylinder is the right size and can be fitted with a bit of a struggle. Other people have used VW Golf ones amongst others.
F9or now I suggest that you remove the cylinder and try to bleed it on the bench in the vice. With your fingers over the outlets, pump until you feel pressure at one of the outlets and then with a spare tube nut and ball bearing block this one and try to get pressure at the second.
Good luck
Paul
The Fulvia cylinder (S1s are worse) can be troublesome. One common problem is the springs: the thing will not work properly if they are replaced the wrong way round (they are different lengths). I can never remember which way they go, so when I take a cylinder apart I arrange everything in order. I should write this stuff down.
I assume that the cylinder was checked for wear and damage inside? An aluminium cylinder over 30 years old is unlikely to be perfect.
On my own car I gave up after three rebuilds and threw the thing into the dustbin. I now use a FIAT iron one that works beautifully. For S2s with servo, the Peugeot 306 cylinder is the right size and can be fitted with a bit of a struggle. Other people have used VW Golf ones amongst others.
F9or now I suggest that you remove the cylinder and try to bleed it on the bench in the vice. With your fingers over the outlets, pump until you feel pressure at one of the outlets and then with a spare tube nut and ball bearing block this one and try to get pressure at the second.
Good luck
Paul
-
P. de R. Leclercq
Re: "bleading" Brakes
You are welcome.
I await developments with interest
Paul
I await developments with interest
Paul
-
Huib
Re: "bleading" Brakes
The longer spring of the two is between the plungers.
The second plunger (counting from the pedal) has either an O ring at the rear or also a cup. If it is the version with the cup, check that the cup is facing backward. All other cups are facing forward.
Your use of words is a bit confusing. In one posting you say the rear brakes are disconnected. In another you say the rear outlet is blocked. Which is it?
Note that there is no a rear outlet on the master cilinder in the sense that it is an outlet for the rear brakes only. The rear brakes are part of the so called mixed circuit. The mixed circuit is operated by the first out let on the master cilinder (counting from the pedal) and drives the rear brakes and the small cilindes on the front callipers.
The second outlet drives the larger cilinders of the front callipers.
Did you check the Fulvia Q&A? Click here if you did not.
The second plunger (counting from the pedal) has either an O ring at the rear or also a cup. If it is the version with the cup, check that the cup is facing backward. All other cups are facing forward.
Your use of words is a bit confusing. In one posting you say the rear brakes are disconnected. In another you say the rear outlet is blocked. Which is it?
Note that there is no a rear outlet on the master cilinder in the sense that it is an outlet for the rear brakes only. The rear brakes are part of the so called mixed circuit. The mixed circuit is operated by the first out let on the master cilinder (counting from the pedal) and drives the rear brakes and the small cilindes on the front callipers.
The second outlet drives the larger cilinders of the front callipers.
Did you check the Fulvia Q&A? Click here if you did not.
-
Tim Heath
Re: "bleading" Brakes
Bryan
I have had this problem and was mistified for a time - and worried too! However, I went back to old principles and left the bleed nipples open one by one until fluid came out starting at shortest line shutting off and going to next etc until get to left rear.
Then with a trusty wife of what ever do it all over again with a bleed pipe pressing on pedel opening nipple and closing when pedel goes to floor slowly lifting the pedel back to start and continue each nipple until no bubbles are seen. Do this all round and it should work.
I would add that I use silicone brake fluid which is more viscous and on one of my fulvias (all series 2) I could not get the brakes to work - just like you. I deduced the problem to the reserviour supply hole which was c .7mm. after opening to I think 1mm the whole system bled fine. Car has subsequently got great brakes and I hope will remain so when I take it round Goodwood for the second time!
Tim
I have had this problem and was mistified for a time - and worried too! However, I went back to old principles and left the bleed nipples open one by one until fluid came out starting at shortest line shutting off and going to next etc until get to left rear.
Then with a trusty wife of what ever do it all over again with a bleed pipe pressing on pedel opening nipple and closing when pedel goes to floor slowly lifting the pedel back to start and continue each nipple until no bubbles are seen. Do this all round and it should work.
I would add that I use silicone brake fluid which is more viscous and on one of my fulvias (all series 2) I could not get the brakes to work - just like you. I deduced the problem to the reserviour supply hole which was c .7mm. after opening to I think 1mm the whole system bled fine. Car has subsequently got great brakes and I hope will remain so when I take it round Goodwood for the second time!
Tim
-
Bryan Dugdale
Re: "bleading" Brakes
Paul which FIAT did you obtain your master cylinder from?.Bryan
-
P. de R. Leclercq
Re: "bleading" Brakes
Hello.
First, please note that my Fulvia s a special. No servo (of course (I don't like them).
The master cylinder (19mm bore) came from a FIAT Regata. It was necessary to make an adaptor plate owing to the orientation of the mounting holes and consequently a longer push rod. Note that my 1967 Fulvia has a Series II steering column...
Paul
First, please note that my Fulvia s a special. No servo (of course (I don't like them).
The master cylinder (19mm bore) came from a FIAT Regata. It was necessary to make an adaptor plate owing to the orientation of the mounting holes and consequently a longer push rod. Note that my 1967 Fulvia has a Series II steering column...
Paul