Technical difficulty bleeding rear brakes

[renault]

Hi all
I am bleeding the brakes on my giardiniera after replacing the seals in the M/cyl. and i am doing this by pressurisung the reservoir. The font brakes bled perfectly - but I cannot get anything to come out of the rear slaves. Any ideas from anyone please?

 

[Vitesse]

Did you bleed the brake wheel cylinders in the correct order. As it is a single circuit system for both front and rear, you need to bleed the rear wheel cylinder furthest from the master cylinder first, then the other rear wheel, then the front furthest away and then the nearest front wheel.

Does the level in the master cylinder go down at all when you are attempting to bleed the rears? If it does and nothing comes out of the wheel cylinder, then it suggests you have a leak somewhere?

How are you pressurising the reservoir? Is it one of these single person kits? Pumping the foot pedal should clear any air out of the brake lines if any has got in. If you are doing it alone, my next step would be to try the two man manual method and go back to basics.

Tony

 

[Twitwalk]

Hi,
I'm guessing this comment is WAY too late for you but this may be of interest. I (my 500F) had the exact same symptoms you describe. Turned out (just today!) that the flexible rear brake lines were blocked. New hoses and the fluid p****s through.
Now to work out why I can't get a solid pedal and why only one brake will lock in an emergency stop. I'm thinking oversize drums with standard shoes.
Regards
Viv

 

[Vitesse]

Viv it could be because one of your brake wheel cylinders has a slight leak it would explain both problems you have. I would take the drum off the wheel that isn't locking and have a look.

Tony

 

[Twitwalk]

Hi Tony,
unfortunately, all wheel cylinders, master cylinder and rear flexible hoses are 'brand spanking'! (Oh, and I put new lining in the front) I'm not sure where to go from here.
Regards
Viv

 

[Hugh Jarce]

Hi Viv

It sounds like only one place to go now and that is check all the lines, looking for kinks, flat spots or just plain damage to the tubes, process of elimination. Even if they are brand new lines, could be a dodgy flare at the end of a line into a junction or cylinder?

Good luck
Hugh Jarce

 

[Twitwalk]

Hi Hugh,
I put in new flexible hoses on the front and that seems to have cured the locking front wheel. It pulls up fairly straight in the dry. Now the only issue (and there has to be one!) is a dragging rear brake. I've backed the handbrake right off but it's still stiff to turn. I have to confess the shoes on that wheel are part worn ones from the front but I understood the self adjusters should re-position and provide the right clearance.
Regards
Viv

 

[Hugh Jarce]

Hi Viv

I have dug up this Technical Tip document; (Author is a chap called Brian Rylance), he was a master at Fiat 500 Technical information and fixes. Have a look through this and see it it helps, it's quite detailed and may point you in the right direction?

Cheers
Hugh Jarce

 

[tjmra]

and are there more articles from Brian........

Joe R

 

[Hugh Jarce]

Hi Joe

I am certain there are, that was one I happened across when I renewed all the brakes during my restoration. I don't think he's with us any longer bless him.

Cheers
Hugh Jarce

 

[fiat500]

That's a really good guide Gary.
I think that you would have to re-use brake shoes on a different axle but at the same side of the car they were originally or they may rub. Purists would scorn re-using anyway. Try driving backwards then giving a good foot on the pedal. That will assure best centering.

 

[Hugh Jarce]

From my opinion, if I was doing anything on the brakes it would be to renew all round and follow the procedure for centralising and setting up the self adjusters, which is as you describe, decent turn of reverse and slam on the brakes. Old cars restored and old brakes retained, not going there.

Cheers
Hugh Jarce

 

[Twitwalk]

Hugh,
wow! Thanks for that, interesting stuff. (yes, I should get out more).
Couple of points that occurred to me as I read it.
1. The wheel cylinders on my 500 are different front to back (Brian says 3/4" front & rear).
2. I didn't know that the pins on the backplate that go in the self-adjusters would wear!!! Well, wear enough to be an issue. My pins were dull and manky and seemed to have a build up of grime on them.
Anyway, my brakes are acceptable now. I took off the dragging brake shoes pushed the self adjusters back to 'as new' position, re-installed them and applied the brake to centre them. This time it's worked.
Thanks for your input.
Regards
Viv
ps I'm posting another query about drive shaft and drive shaft joint wear.