Technical Brakes again...

[xf1ref]

Pads are loose, calipers were cleaned with steel wire brush.
Sliders are sliding like in the video. Pistons are without rust, new square rings and are sliding easy.

I have no clue why brakes are overheating. I drove the car with a lot of engine brake and no change, same overheating.

The last thing I'm thinking is to change the brake pump.

 

[A3jeroen]

Sometimes the rubber lines deteriorate on the inside allowing the fluid to push the pistons out, but not back in.
Been there, done that.

gr J

 

[koalar]

Have you bleed them recently?

Both sides the same?

 

[xf1ref]

Both rubber lines are new, new brake fluid, new o-ring on both calipers and at the end bleed all the wheels.
Both front sides are overheating the same. The rear drums are just warm.

 

[koalar]

Both sides getting hot

It's had new

Pads
Piston seals
Brake lines
Discs
Brake fluid
piston gasket

Also

Bleed
Calipers cleaned
Sliders checked
Pistons are not corroded
everything is cleaned and copper greased

And the rears are fine but the font wheel nuts get hot to touch


You can't check easy just by spinning the wheel as its alway some drag in the gearbox

I'd start by taking the pads and slid pins out and cleaning all the grease off and taking it for a test drive and seeing if it improves, I can"t stress enough the pads should be rattle loose in the carrier if there not there's no way for them to push back as the disc heats and expands

Binding brakes are dangerous if the fluid overheats and boils you loose your brakes, hot wheel nuts can't be far off, I take it you don't live in the Carpathian Mountains or similar

 

[vexorg]

Binding brakes are dangerous if the fluid overheats and boils you loose your brakes, hot wheel nuts can't be far off, I take it you don't live in the Carpathian Mountains or similar

I've always found you'll cook the pads before the fluid or nuts/bolts fail.

Jack the wheels up, spin them and stomp on the break and check if there's any drag from the brakes on the wheel, should spin free again.

Refurb calipers would be my next port of call, all new an warrantied.

 

[Yolanda]

Find a slight gradient. With the handbrake off will the car roll, if it does I'd be looking at the wheel bearings. I know it's unusual for both to be at fault at the same time, but have they been over tightened when the work was done.

 

[koalar]

Was there a problem before the disc and pads were changed?

Does is smell bad?

@Yolanda makes an excellent point, are we sure it the brakes rubbing,

Regardles of what you read on here or the Internet, even in neutral the front wheels never spin freely unlike the rears

The drive shaft is still connected to the differential which sits in gear oil, the wheel stop within about a second of spinning it, does not help if you lift both front wheel just the opposite wheel will turn the other direction

 

[jrkitching]

I can"t stress enough the pads should be rattle loose in the carrier

That. There are varying opinions as to whether (or not) they should be lubricated, and with what, but all the regulars on here agree they need to be perfectly free to move.

The contact surfaces on the carriers also need to be perfectly smooth and free of corrosion; easy enough with a rotary wire brush in a drill, but you need the carriers off the car to do it properly.

My money is on the pads sticking in the carrier. Sometimes with aftermarket pads it might be necessary to take a file to them; it's not that uncommon to find a blob of excess paint in exactly the wrong place.

It's unusual to find a caliper sticking on its slide pin, and even more unusual to find a sticking caliper piston, but both can happen.

Wheel bearings can and do run hot just before they fail, but 1) it's unlikely both would do this at the same time and 2) once they do start to run hot, it usually isn't more than a few miles before they fail outright. So in this case I doubt that's the cause of your problems.

Whatever, this is a priority job which needs fixing asap.

 

[koalar]

That. There are varying opinions as to whether (or not) they should be lubricated, and with what, but all the regulars on here agree they need to be perfectly free to move.

Yep there's no right or wrong answer here, even manufactures, can't agree, probably depends where you live, and type of driving you do, copper grease isn't ideal for the pistons and slides though, but no big deal.

The contact surfaces on the carriers also need to be perfectly smooth and free of corrosion; easy enough with a rotary wire brush in a drill, but you need the carriers off the car to do it properly.

My money is on the pads sticking in the carrier. Sometimes with aftermarket pads it might be necessary to take a file to them; it's not that uncommon to find a blob of excess paint in exactly the wrong place.

It is very common, but it can be tricky to diagnose as when the discs cool down as you jack it up they tend to free up again

Whatever, this is a priority job which needs fixing asap.

Correct

 

[xf1ref]

Jack the wheels up, spin them and stomp on the break and check if there's any drag from the brakes on the wheel, should spin free again.

I did, with the engine running and in the 4th gear to spin the wheels for some minutes. The discs were cold.

Find a slight gradient. With the handbrake off will the car roll, if it does I'd be looking at the wheel bearings

I tried also this in traffic and letting the car to roll at slow speed and is rolling, not like my other car but is rolling. Good point with the bearings.

Was there a problem before the disc and pads were changed?

Does is smell bad?

I observed this at the beginning of the summer when I changed the rear brake shoes. It doesn't smell at all, no smoke or something else.

It's like the car brake only with the front and even so is not a heavy car. My other car has almost 1.9 tons and always the alloy wheels are just warm.
I will return with some pictures/short videos to showcase how the front wheels are turning with/without pads.

Whatever, this is a priority job which needs fixing asap.

It was a priority all the summer but after changing almost everything at the front brakes I started to wonder maybe is in my head and the brakes are fine. I don't know anyone else with a Panda to compare.

 

[The Panda Nut]

Copper grease best restricted to the back of pads as a sticky layer to absorb vibration and reduce brake squeal. It gets thick quite quickly and dries out causing as many issues as it causes if used anywhere else. Get some brake grease such as Bosch type for all lubrication duties. Im pretty sure any issues with the caliper dust cover around the piston will lead to sticking pistons before long as once water and road dirt gets underneath the dust seal throughany holes, sticking brakes more or less to be expected. My experience has been this will lead to replacement calipers being required and if they have stuck once you need to be ready to change the calipers. Fortunately these are not expensive for the Panda and they start from about £45 each. It will restore the brakes. I have spent many an hour working calipers back and forth to try and overcome seizure. I have an oval section bar the allows the piston to reach the end of its travel but no more, so I take the caliper off and place this in the middle of the caliper jaw and then pump the pedal to get the pistomn out. Rotating this bar acts as a cam and pushes the piston back even when very stiff. Repeating this many times working the pistons fully in and fully out does tend to free things for a while but its not a proper fix and its time consuming. I would just change the calipers and be done with it. I agree with the other advice and would do as many do on here and dismantle and clean things with a wire brush at least once a year to make sure everything stays free as it should. Always be very careful not to damage the seals when doing any maintenance, for all the reasons above.

 

[koalar]

The wheels neither front or rear got warm let alone hot on my old panda with steel wheels, even on long journeys

I have never checked this car with alloys

The amount of braking front to rear depends how hard you push the pedal

At light loads is close to 50/50

As you press the pedal harder more is transfered to the front

Cars with abs trainsfer less so

I can't be bothered to get a ruler and calculator out but by eye it looks to be 60/40 ish front to rear under heavy braking

If the brakes are binding you should smell it is as soon as you get out of the car

Try removing the wheel centres and take it for a drive does the centre nut get hot, be careful don't burn yourself

Of course it all depend how you drive the car

 

[xf1ref]

I just bought an infrared thermometer to come with some measurements also.

My experience has been this will lead to replacement calipers being required and if they have stuck once you need to be ready to change the calipers. Fortunately these are not expensive for the Panda and they start from about £45 each.

I changed the piston seal at both calipers and there is no rust on piston or cylinder. That's why I did not changed the whole caliper. On both calipers the pistons are sliding easy and they are not stuck. After braking I can turn the wheel with the my hand.

Now regarding the front bearings, I checked and on panda and there are two rows ball bearings with two inner rings for which doesn't matter how much the driveshaft nut is tighten.

 

[Yolanda]

You can still over tighten that type of bearing, that's why they have torque value.

 

[Yolanda]

A thought's just occurred to me ,could it be an intermittent fault with the master cylinder sticking.

 

[koalar]

No smell
No noise
No feedback

Equals no idea



We need to know how the cars being driven,

We need to know where it's being driven, flat hilly so on

No smell probably rules out brakes

You can just reach the disc laying on the ground. You do have to be quick so as not to burn yourself if it is rubbing

Without knowing which part is getting the hottest, we will remain in the the dark

 

[vexorg]

If the bearings were that bad you should be able to hear them rumbling and groaning away.

 

[xf1ref]

I made some small videos to see how the wheel are turning before and after removing the pads and how the pads are not blocked in the carrier.
Before removing the pads

After removing the pads

Pads in the carrier

A thought's just occurred to me ,could it be an intermittent fault with the master cylinder sticking.

I'm also thinking at this.

 

[koalar]

My stupid phone will not play 4K video I had to download them and convert to a lower resolution

Are you sure you have a brake problem

The discs don't look Glazed

The pads are always slightly in contact with the disc

I will not have my car here till Wednesday to compare, from memory it looks about right

Are both the pads the same thickness?

I guess your car will have an ABS unit?

If you suspect a hydraulic pressure problem just eliminate it by opening the bleed nipple