Technical 500 Brakes

[panda1408]

Hi all,

My dad has recently bought a 1973 500L, it has had a full restoration and is in imaculate condition. However we are having some trouble with the brakes, they dont work very well at all!

The main problem is that the pedal goes right down to the floor, there is resistance but there is very little braking effect, which means the handbrake is usually required to stop.

The previous owner changed the front brake shoes just before we bought the car, he also said he sprayed WD40 into them, the car hadn't been driven at all after he did this, so we thought the brakes may get better after it had been driven abit, however they haven't. We took the drums off today and cleaned them and we also dried out any moisture on the shoes and drums with a blow lamp but they are still as bad.

Could it possibly be the master cylinder on its way out?

Are the brakes on the 500 usually quite good? They must definitely be better than ours are!

Thanks for your help
Freddy

 

[DjPatD]

hows it goin? this is a interesting problem? i have had the same issue but it simply turned out to be the coil that the break pedal depresses as it is pressed. it could also be something as simple as the return spring? my breaks work fine for a car that has had its original breaks not replaced. if not then i would def. replace the mast. cylinder, as i had to in another one of my cars due to the same issue.

good luck - cheers from brooklyn ny

 

[Panda Van]

Hi panda 1408 !

Are all the wheel cylinders working correctly, this may be worth checking that they are pushing out the brake shoes sufficiently and also check theyre not leaking.

The brake drums have very low wear tolerance, if theres any sign of wear or grooves inside the drums, they may also be worth replacing.

Also how low are the break shoes and how long have they been fitted?

All things worth checking, brake parts are relitavely cheap for them and some times worth changing as a matter of course, ecpecially if its been stood a long time. As for your master cylinder, just make sure theres no sign of leakege, itll be obvious if it is as brake fluid tends to strip paint

Hope this helps ?

 

[panda1408]

Thanks for you help guys.

Panda Van: We have checked everything and it all seems fine, there are no leaks from the master cylinder or wheel cylinders, the front brake shoes are brand new and have done about 20 miles. The rear shoes have plently left on them, we dont know how old they are, although they wont have done many miles at all. All the pipes look fairly new and there are no leaks anywhere, also all the return springs are fine.

DjPatD: What exactly do you mean by the coil that the brake pedal depresses?

We are really puzzled about what could be wrong, it feels as if only the rear brakes are working, but we have tested the front and they do stop the wheels when it is jacked up.

Thanks again for you help
Freddy

 

[Panda Van]

What happens if you pump the pedal ? Is it worth bleeding the system ?

 

[panda1408]

It makes no difference if you pump the pedal, you get a solid pedal 3/4 of the way down.

 

[panda1408]

An update to this:

After bleeding the brakes and it making no difference at all we decided it had to be the master cylinder. We have taken it off and think we have found the problem, the inner seal is competely the wrong type, it is way too big and is just a normal round seal rather than the type with an extra lip like the outer seal is. It can't be sealing very much at all. Hopefully once we have changed that everthing should be ok. Does anybody know if the seals are easy to get hold of? The actual cylinder is fine so there is no need to replace it.

What we can't understand is how the car passed an MOT in July, there are basically no brakes at all which it would obviously fail on, also the drivers side front wheel bearing is shot so that would of probably failed aswell.

Freddy.

 

[Panda Van]

Glad to hear youve found the problem, probably the best bet is chet at Ricambi to find seals, and if she hasnt any shell know someone who does.
http://ricambifiat500.com/category/spare-parts/

 

[panda1408]

Thanks Panda Van, we know about Ricambi but we couldn't see any seals on there, anyway my dad has spoken to a place called past parts in Suffolk which someone he knows gave him the details of. It turns out the seals are actually correct. They had a master cylinder in stock so we will hopefully be recieving and fitting that tomorrow. It should hopefully solve the problem, if it doesn't who knows what is wrong!

 

[Panda Van]

Good luck - hope that solves it !

 

[panda1408]

Turns out it wasn't the master cylinder . It was actually one of the return springs. One was replaced when the new shoes were fitted and it was smaller than the original one. It meant that it didn't let the shoes move out far enough. We've taken it off and now we have brakes!!

 

[DjPatD]

sorry for the late response, i havent been on in a while. i knew that i was that return spring. i had the same problem. anyways im having another problem with my brakes as well, im losing alot of breaking fluid on the front right tire, and now they brakes dont work at all, i have to use the handbrake?. could this possible be the master cylinder?

 

[Panda Van]

It sounds more likely its the wheel cylinder DJpatD..................

 

[panda1408]

sorry for the late response, i havent been on in a while. i knew that i was that return spring. i had the same problem. anyways im having another problem with my brakes as well, im losing alot of breaking fluid on the front right tire, and now they brakes dont work at all, i have to use the handbrake?. could this possible be the master cylinder?

:bang:We weren't quite sure what you were refering to in you first post, and as all the springs looked fine we never thought that they might be the wrong ones. Could have saved alot of messing about if we had checked them - very annoying. Oh well at least we now have a new master cylinder and fresh fluid so these shouldn't need any attention for a while hopefully.

The most annoying bit is we have managed to ruin the bonnet while testing the brakes. My dad didn't shut it properly and it flew open whilst driving along, so it now has a nice dent in it

DJPatD your problem definately sounds like the wheel cylinder to me aswell.

 

[Panda Van]

oooooooooh panda1408, it seems youre having a run of bad luck with the bambino at least youre brakes are sorted tho'