Technical  Binding rear brake (perhaps)

Currently reading:
Technical  Binding rear brake (perhaps)

romniox789

Member
Joined
May 3, 2026
Messages
51
Points
67
Location
UK
When my 500F car is cold all wheels are free and I can roll it just fine. But, after a 5 mile drive, the rear left wheel feels like its binding (I put it up on a jack and confirmed that's the wheel that is sticking'. It smells very hot too of course...

Before I disassemble the hub, any tips on what I should be looking for? Seems weird it only does it after a drive - maybe something sticking...?

All thoughts welcome!

Cheers
 
It sound like a brake hydraulic cylinder is sticking from your description.
With the brake drum off, take two flat screwdrivers and use them gently against the brake shoes to rock them left and right, you should see the brake pistons in the cylinder move easily forward and back, it sometimes helps to ease the rubber dust covers back to see the operation.
What often happens is one piston sticks a bit so although the brake appears to work when released it doesn't full retract with the action of the brake shoe return springs.
You can also do this with someone pressing and releasing the brake pedal gently, but note, if the push to hard a brake piston will pop out and lose brake fluid all over you brake shoes.
If doing it that way it is a good idea to keep the two screwdrivers in place to control movement as often only one piston will move at first.
Remember you only want a small amount of movement or piston will pop out.:(
 
Super helpful thank you. I messed up with the piston over-extending on an old polo many moons ago :)

Qq, if it’s sticking is there any fix or is it new cylinder time?
 
Super helpful thank you. I messed up with the piston over-extending on an old polo many moons ago :)

Qq, if it’s sticking is there any fix or is it new cylinder time?
If in doubt then for safety fit a new cylinder.
However if only mildly dragging and you are very careful I have eased the dust covers back, then often if only one piston sticking slightly it can be possible by jamming the good one closed/in gently have you assistant very carefully push the sticking piston out as far as you dare ;) and then clean any slight corrosion off with an old toothbrush or similar using a bit of clean brake fluid, then refit dust cover, push the piston back in and using the two screwdriver trick rock the two pistons and shoes forward and back until it feels easier, clean up and refit the dust cover.
Note if you push the piston out too far and brake fluid comes out then best option is a new brake cylinder and I am only talking about a mild sticking.
Once done then the brake shoes should pull the pistons back in with every press of the pedal and with drum fitted you should see if lucky or not.;)
As the piston is not exposing the pressure seal then no need for bleeding etc. But only if very careful.
Also if any sign of brake fluid when easing dust covers back even before trying to free off, don't hesitate, fit a good quality new brake cylinder.
 
OK, off to Halfords for some brake cleaner and then I shall investigate! I just saw the price of brake cylinders; agree - replacement would be a good idea.
 
Brake pedal seems to do nothing, even the handbrake seems to do nothing.

In the attached video, you can see me beginning by applying the handbrake and the mechanism moving inside and then releasing the handbrake, and then applying the foot brake multiple times and nothing seems to happen…

When I use two screwdrivers I can move the top of the brake pads left and right and the cylinder move moves respectively in and out depending on which side I’ve moved it to.

Any ideas?
 

Attachments

  • IMG_4369.mov
    17.7 MB
It’s like the pads are pushed out at the top by the brake cylinder, butif I try and ease it back on one side of the brake cylinder it just pushes the pad out via the piston on the other side. There is a notable difference that the pad are further out at the top by the brake cylinder than they are at the bottom.
 
It’s like the pads are pushed out at the top by the brake cylinder, butif I try and ease it back on one side of the brake cylinder it just pushes the pad out via the piston on the other side. There is a notable difference that the pad are further out at the top by the brake cylinder than they are at the bottom.
The handbrake lever is not actuating the brake shoes at all.
It all looks a little out of line as though it is all high up on the back plate, is the handbrake linkage assembled correctly in the shoes compared with the other side.
Are the brake shoes correct for that side of the car as normally the leading shoe has more of a space on the material from the wheel cylinder piston , if you know what I mean.
I see the shoes and cylinder all look quite recent.
With those type of self adjusters if they are not good quality what happens is they back off when the return springs are stronger than the self adjuster pad springs.
I don't know how far you have been able to road test , but can you see wear marks where the shoes are contacting the brake drum, it all looks a bit off centre to me.
Can you take a photo of the other side as well please, something is not correct on the assembly.
At least the brake cylinder is not seizing, but you say nothing is happening when you press the foot brake, do you mean the pedal is hard or soft and to the floor? I can see it is not reacting.
If you fitted the shoes etc. did you compare them with the originals?
 
I have only had the car a month, I was told that a year ago some recommissioning work was done, which included brakes (but the car hadn’t been driven after that work). So somebody has been in here doing stuff…

Yes, I noticed the handbrake isn’t doing anything either – it’s quite odd.

At the moment, pedal travel is not great, but not horrific, and the car does seem to stop ok. But I noticed that it smelt very hot a few times when I’ve parked it and although I can still push the car, I can hear and feel it stopping as if the handbrake is up a notch or two - which to me says binding brake…

The drum was hard to get off because it has been done up ridiculously tight , although it didn’t take the pads off the mounting points when it came off eventually. In prodding and poking, I know I’ve moved them, but I thought I had re-centralised them. I will take the other side off tomorrow but access is a bit of a pain. I will need to reassemble this side first and move the car.

It is entirely possible that what you see in here is not right. There are at least two other things on the car that I consider not right (like fuel hose going straight through the chassis without a grommet). I have no reference point though, as this is my first 500.

Have a look at the photos, I find the pad wear very odd. There is a strange amount off the top on both sides. But the actual outside of the brake pads seems to have fairly light wear. I must’ve driven it at least 100 miles now. The hub feels fine inside though, no grooves. I wonder if this brake is actually doing anything…
 

Attachments

  • IMG_4370.jpeg
    IMG_4370.jpeg
    2.1 MB · Views: 18
  • IMG_4372.jpeg
    IMG_4372.jpeg
    1.7 MB · Views: 9
  • IMG_4373.jpeg
    IMG_4373.jpeg
    2.1 MB · Views: 15
  • IMG_4374.jpeg
    IMG_4374.jpeg
    2 MB · Views: 7
  • IMG_4375.jpeg
    IMG_4375.jpeg
    2 MB · Views: 8
  • IMG_4376.jpeg
    IMG_4376.jpeg
    2 MB · Views: 12
I have only had the car a month, I was told that a year ago some recommissioning work was done, which included brakes (but the car hadn’t been driven after that work). So somebody has been in here doing stuff…

Yes, I noticed the handbrake isn’t doing anything either – it’s quite odd.

At the moment, pedal travel is not great, but not horrific, and the car does seem to stop ok. But I noticed that it smelt very hot a few times when I’ve parked it and although I can still push the car, I can hear and feel it stopping as if the handbrake is up a notch or two - which to me says binding brake…

The drum was hard to get off because it has been done up ridiculously tight , although it didn’t take the pads off the mounting points when it came off eventually. In prodding and poking, I know I’ve moved them, but I thought I had re-centralised them. I will take the other side off tomorrow but access is a bit of a pain. I will need to reassemble this side first and move the car.

It is entirely possible that what you see in here is not right. There are at least two other things on the car that I consider not right (like fuel hose going straight through the chassis without a grommet). I have no reference point though, as this is my first 500.

Have a look at the photos, I find the pad wear very odd. There is a strange amount off the top on both sides. But the actual outside of the brake pads seems to have fairly light wear. I must’ve driven it at least 100 miles now. The hub feels fine inside though, no grooves. I wonder if this brake is actually doing anything…
So it looks like two strange things at least.
Why is there no hydraulic action on that brake cylinder and obviously check that operation when you can access the other side.
Also the hand brake action, I suspect the handbrake lever inside the braked rum where it goes between the two brake shoes is either not located correctly or something broken.
I am not sure regarding the quality of the rear shoes as well. There is also the odd wear marks as though the shoes are not sitting in line with the drum correctly, it can be difficult not being beside the car, just looking at pics.
See if the other side brake cylinder is working, it is almost like a brake pipe or something is damaged not letting brake fluid into that wheel cylinder on the binding side.
When you go about reassembling make sure the handbrake adjustment is back right off before you start, as you have to get it perfect in the brake drum before any external adjustment.
On your self adjusting mechanism when everything is correct the shoe self adjusters sit on pins that should locate them, the theory is when you press the foot brake and work the handbrake those self adjuster friction pads allow the shoes to move closer to the brake drum but not drag. What I have found often happens is if cheap quality brake shoes have been fitted the brake return springs over rule the friction pad adjuster so the shoes move back and you have a slack brake pedal and also a poor handbrake, what sometime happens is people try to correct it by over adjusting the handbrake making matters worse.
There are ways around it by weakening the top return spring, but ideally a good quality set of shoes should self adjust correctly.
When ever I work on that type of adjuster I ease the shoes outwards with a screwdriver to just about get the drums on, then when drums fitted give the drum a gentle tap with a copper mallet this squares the shoes up so they are close to the drum but not dragging so as good as possible and then adjust the handbrake cable side.
From what you have found and also said about the fuel pipe through the chassis etc. it sounds like you will be busy putting it right so you feel happy to drive it safely.
There are several on Forum who have a greater more specific knowledge of your model like @the hobbler who can advise. My knowledge is more general after over 50 years working as a general motor engineer on all makes, not Fiat specifically.:)
 
That is super helpful, thank you. I am gradually working my way around the car trying to make sure that is mechanically sound. It took a while to get it running right, mostly because it had sat for quite a while. Paintwork and general metal work is good, far better than I was expecting, so brakes were next on the list. I’m not surprised to find something isn’t quite right - I’m coming to the conclusion that if the car is 54 years old, every part will have been messed about with at least once, perhaps by someone under more time pressure than me!
 
Last edited:
So with a pair of grips, I was able to compress the pistons back into the cylinder, taking it out of the extended position. However, applying the brake pedal does not make the piston move back out. Very odd. Tomorrow I will see what the other side is like.
 
So with a pair of grips, I was able to compress the pistons back into the cylinder, taking it out of the extended position. However, applying the brake pedal does not make the piston move back out. Very odd. Tomorrow I will see what the other side is like.
If you slacken the brake bleeder and some one gentle/slowly presses the brake pedal down see if air/brake fluid comes out, if fluid starts to come out retighten the brake bleeder and stop the assistant pressing the brake pedal.
Ideally fluid should have come out and brake cylinder pistons start to move.
However I suspect your problems are not that easily fixed.
If no fluid comes out and brake pedal still feels as before then I suspect something is blocking the brake pipe, either a very damaged pipe or hose blockage, that or some idiot has left a brake pipe clamp still on a flexible hose underneath. Occasionally a flexible hose will get blocked internally, but not that common.
It all sounds very strange, what did the brakes, foot and hand feel like on the road?
If you need to go under the car make sure it is safely supported on axle stands, never trust a car jack!
When you tried my suggestion at the beginning using two screwdrivers to rock the shoes left and right I would have expected that to have pushed the brake cylinder pistons back and forth at the same time telling us the cylinder wasn't seized, so I am surprised you needed a pair of grips, unless the self adjusters were stopping you get enough movement.
If brake cylinder is in good order I can usually push the pistons in with my fingers.
Don't forget even when you have solved the reason for the hydraulic brake cylinder issue not working, there is still the handbrake assembly side in the brake drum not activating the brake shoes.
I think you are being kind saying "every part will have been messed about with at least once, perhaps by someone under more time pressure than me!" Personally I would say a very inexperienced DIY has been tampering with the car and that is me being kind!
If this is a sign of the work on the rest of the car then a very careful thorough inspection is called for before using the car regularly on the road!:(
 
Well, I just looked at the front wheel on that side before turning it round to look at the back - see pictures. The cylinder pistons move in and out just as I would expect. Interestingly, the brake pads are much more firmly fitted in this case a the pins that they sit on - the whole assembly seems very firm. I think in taking the hub off I knocked the brake pads off the pins at the back, but I had used a rubber mallet to encourage them back into place so I’m not 100% convinced that there isn’t some sort of overall fitment problem on the back, because they seemed aligned. It’s very strange that I had to use the grips to get the Pistons to retract, it was not a small amount of effort to do it either. Yet, when I use the two screwdrivers I could move the brake pads left and right and see the pistons moving in and out correspondingly on either side in tandem.

On the road, the brakes felt ok, which, I was given an invoice for work done before I bought where brake cylinders brake pads and brake hoses were replaced – and the car had done virtually no miles since then. Under very firm braking there was movement to the right hand side of the road, but the roads are so bad round here and so cambered it was difficult to properly judge that.

Now for the alarming bit… when I took the front brakes apart, the locking nut that secures the drum case on, and seats the bearings was not Torqued up - at all. I thought I was going to be up for a battle, but although it looks like somebody went at it fairly hard to flatten the side of the nut off, it required barely any force to undo. I’m assuming that given that is the only bolt holding the entire thing together, it should be torqued up hard?

Even more curiously, I found a YouTube video talking about that nut, which suggested is a reverse thread. Well not in my case…! To undo the hub nut required an anticlockwise rotation, which is the same rotation that the wheel travels in. On a scale of one to 10 I’m trying to stop my alarm from being at level 10, and I’ve walked away to get a cup of tea and post this message…
 

Attachments

  • IMG_4388.jpeg
    IMG_4388.jpeg
    1.1 MB · Views: 7
  • IMG_4389.mov
    39.1 MB
  • IMG_4383.jpeg
    IMG_4383.jpeg
    189.3 KB · Views: 6
  • IMG_4384.jpeg
    IMG_4384.jpeg
    188.7 KB · Views: 7
Brake pedal seems to do nothing, even the handbrake seems to do nothing.

In the attached video, you can see me beginning by applying the handbrake and the mechanism moving inside and then releasing the handbrake, and then applying the foot brake multiple times and nothing seems to happen…

When I use two screwdrivers I can move the top of the brake pads left and right and the cylinder move moves respectively in and out depending on which side I’ve moved it to.

Any ideas?

The handbrake "strut" between the shoes appears broken ie it looks like the moving lever has come adrift from it's pivot point on strut

Re mention strange shoe wear on drum not working at - friction material chamfered at end to stop shoe grabbing drum when applied =normal if in your shoes case bit carelessly carried out.
 
Last edited:
I know nothing of wheel bearing type on 500 but if taper rollers with no central tube the nut is not fully tightened.
The hub nuts you have are ruined and you need new nuts that can be correctly staked.

Do you have the correct manual? If not you need one.

@the hobbler Please help
 
I have only had the car a month, I was told that a year ago some recommissioning work was done, which included brakes (but the car hadn’t been driven after that work). So somebody has been in here doing stuff…

Yes, I noticed the handbrake isn’t doing anything either – it’s quite odd.

At the moment, pedal travel is not great, but not horrific, and the car does seem to stop ok. But I noticed that it smelt very hot a few times when I’ve parked it and although I can still push the car, I can hear and feel it stopping as if the handbrake is up a notch or two - which to me says binding brake…

The drum was hard to get off because it has been done up ridiculously tight , although it didn’t take the pads off the mounting points when it came off eventually. In prodding and poking, I know I’ve moved them, but I thought I had re-centralised them. I will take the other side off tomorrow but access is a bit of a pain. I will need to reassemble this side first and move the car.

It is entirely possible that what you see in here is not right. There are at least two other things on the car that I consider not right (like fuel hose going straight through the chassis without a grommet). I have no reference point though, as this is my first 500.

Have a look at the photos, I find the pad wear very odd. There is a strange amount off the top on both sides. But the actual outside of the brake pads seems to have fairly light wear. I must’ve driven it at least 100 miles now. The hub feels fine inside though, no grooves. I wonder if this brake is actually doing anything…
Something is wrong with this brake, from your video I think you are missing the pin that connects the two levers, the spring that brings the handbrake lever to its initial position is also missing. The brake cylinder that controls the brake shoes seems blocked, its pistons should go back slightly when pressed by hand. If the brake shoes have worn out because they were not properly seated in the drum and if the brake cylinder is blocked, I would replace all these parts with new ones... bad brakes can put your life in danger,,, especially in this Fiat that does not even have 0.10 Euro NCAP safety stars. 😁
 

Attachments

  • Screenshot_20260628_123441_Chrome.jpg
    Screenshot_20260628_123441_Chrome.jpg
    1.2 MB · Views: 20
  • leva-freno-a-mano-sx.jpg
    leva-freno-a-mano-sx.jpg
    198 KB · Views: 15
  • Screenshot_20260628_123604_Chrome.jpg
    Screenshot_20260628_123604_Chrome.jpg
    1.2 MB · Views: 18
Something is wrong with this brake, from your video I think you are missing the pin that connects the two levers, the spring that brings the handbrake lever to its initial position is also missing. The brake cylinder that controls the brake shoes seems blocked, its pistons should go back slightly when pressed by hand. If the brake shoes have worn out because they were not properly seated in the drum and if the brake cylinder is blocked, I would replace all these parts with new ones... bad brakes can put your life in danger,,, especially in this Fiat that does not even have 0.10 Euro NCAP safety stars. 😁
I don't think it helps you because of Brexit but I bought brake drums and shoes from passione500.it and I'm happy. I see they also have the Complete Brake Shoe Plate at a civilized price - including VAT for Europe I see the price is 59 euros.

https://passione500.it/fiat-500/fia...tro-fiat-500-n-da-n-per-ricambi-058003-d-f-l/
 
Back
Top