Technical 1969 Fiat 500L Brake

[av8r]

Hello, I am inquiring for some help. My brake pedal has no friction when I apply brakes.

I realised I left my vehicle in the garage for too long, today I refilled my brake fluid reservoir that I found empty. After replenishing it, I applied brake and brake pedal had zero friction and no brake application meaning brakes are not working and feels as that the pedal has no pumping action. I believe it is the brake master cylinder, but can locate where is it at, and also I am inquiring for any other ideas of what might be since I could be wrong on my dignosed

 

[bugsymike]

Hello, I am inquiring for some help. My brake pedal has no friction when I apply brakes.

I realised I left my vehicle in the garage for too long, today I refilled my brake fluid reservoir that I found empty. After replenishing it, I applied brake and brake pedal had zero friction and no brake application meaning brakes are not working and feels as that the pedal has no pumping action. I believe it is the brake master cylinder, but can locate where is it at, and also I am inquiring for any other ideas of what might be since I could be wrong on my dignosed

If definitely brake fluid reservoir was empty and had to be topped up quite a lot I would look for a wet patch under car or around brake drums/wheels etc. As more likely a rusted brake pipe or a leaking wheel cylinder in the brake drums.
Brake master cylinders on older cars usually leak from the back seal and down the brake pedal, resulting in the pedal rubber falling off and mess on the mat. If that is the case, get down on your knees and shine a torch up around the area above the pedals for evidence.
If a master cylinder fails and no loss of fluid it is often the pressure seals inside the brake master cylinder.

 

[av8r]

If definitely brake fluid reservoir was empty and had to be topped up quite a lot I would look for a wet patch under car or around brake drums/wheels etc. As more likely a rusted brake pipe or a leaking wheel cylinder in the brake drums.
Brake master cylinders on older cars usually leak from the back seal and down the brake pedal, resulting in the pedal rubber falling off and mess on the mat. If that is the case, get down on your knees and shine a torch up around the area above the pedals for evidence.
If a master cylinder fails and no loss of fluid it is often the pressure seals inside the brake master cylinder.

I believe I did see a spot of some sort of fluid on the carbox I keep under the card to avoid staining the garage. My issue is that I believe your recommendation is correct, but how come after filling up the reservoir the fluid level now stays the same and the pedal does not build any pressure back. Unless it is a massive leak or small, massive leak will empty the reservoir in minutes, small leak would kind of build pressure on the pedal and starts leaking again. In my case I have now full reservoir and zero pedal back pressure, and of course zero braking action

The stain I found was on the rear left between the rear left tire and the door on the outside, on the floor

 

[bugsymike]

I believe I did see a spot of some sort of fluid on the carbox I keep under the card to avoid staining the garage. My issue is that I believe your recommendation is correct, but how come after filling up the reservoir the fluid level now stays the same and the pedal does not build any pressure back. Unless it is a massive leak or small, massive leak will empty the reservoir in minutes, small leak would kind of build pressure on the pedal and starts leaking again. In my case I have now full reservoir and zero pedal back pressure, and of course zero braking action

The stain I found was on the rear left between the rear left tire and the door on the outside, on the floor

If the master cylinder has been empty for a long time the seals may have dried out and stopped being able to pump rather like an old push bike tyre pump with the piston going up and down but no resistance felt.
You could try undoing the brake pipe union at the master cylinder and try gently pumping, it may be a messy job.
In the past I have bled / primed a completely dry new master cylinder held carefully in a vice on the bench, by pouring fluid in and gently pumping it whilst holding my fingers over any outlets to act as one way valves until clean brake fluid came out and then fitted to vehicle doing the final bleeding at the master cylinder before tightening the brake pipes to the point the pedal has been hard with no air in system and without going under car at all.
However as your vehicle has been standing for a length of time a full inspection of the brake system is advised as it would be quite possible the wheel cylinders seals have started to fail also.
It would be a good idea to give the entire brake metal pipes and rubber hoses a good inspection.
As they say "If a car will not start it is a nuisance, if a car will not stop it can be fatal!

Re the stain, that is an odd place for a brake fluid leak unless a brake pipe runs along there or in the sill it's self as some cars I have found.

 

[Goldnrust]

The stain I found was on the rear left between the rear left tire and the door on the outside, on the floor

I would have a good look at the rear left brake lines then. The hard line runs from the brake forward along the inside edge of the wishbone, towards the front mounting point of the wishbones. There’s then a short flexi line, and a hardline running across the back of the floor and into the central tunnel.

If you have a leak towards the back of the car, you will have air in the lines. Once you have identified the leak and fixed it, you will need to bleed the full brake system to get the air out before the pedal will do anything.

As @bugsymike rightly points out, braking system issues are not to be taken lightly. If you are in any doubt, make sure to get help from someone who is more experienced, or take the car somewhere to have the problem looked at. It’s just not worth taking the risk.

 

[av8r]

Where is the master cylinder located at?

 

[Goldnrust]

If you look under the front of the car, on the drivers side just forward of the spring there's a bulkhead on to which the steering components and brake master cylinder are mounted. It should be fairly easy to spot.

 

[Ferdinand01]

Hello, I am inquiring for some help. My brake pedal has no friction when I apply brakes.

I realised I left my vehicle in the garage for too long, today I refilled my brake fluid reservoir that I found empty. After replenishing it, I applied brake and brake pedal had zero friction and no brake application meaning brakes are not working and feels as that the pedal has no pumping action. I believe it is the brake master cylinder, but can locate where is it at, and also I am inquiring for any other ideas of what might be since I could be wrong on my dignosed

Here is use full link

Haynes workshop manual for the FIAT 500

it is to the Haynes workshop manual