Technical Front passenger side brake overheat!

[Theflyingpostman]

I have been fit new pads and disc front of my Punto, after drove 12 miles start smell funny out of my air conditioning, I stopped and look what is wrong with my engine it wasn't and I see white smoke out of my passenger side front wheel and I feel the heat is absolutely so hot!
I had to return back home! and look into it again and I have found that the caliper piston rubber seal had a hole which the damp have gone in and rusty the caliper piston cylinder.

I have remove the caliper piston, clean it with brake fluid and try to remove the lump rusty on the surface it become nice smooth and refit back in. Put all the pads back in and drove it was fine but when I apply the brake first time since refit it becomes difficult to acceleration like I was hold the brake at the same time as the acceleration!

Are the piston in caliper are suppose to move back in when release the brake pedal? do you think need new caliper? the new pads and disc it can't be a faulty?

Any suggest what is wrong please let me know cos I am confused why is stuck again after I have clean it.

 

[varesecrazy]

Hi

yes..probably still the piston getting stuck

If yhe rubber boot has a hole in.. then grit has probably scratched the surfaces

You can try and smooth with 'wet and dry paper' but with the boot letting dirt in it will seize again after time

 

[jackwhoo]

I have been fit new pads and disc front of my Punto, after drove 12 miles start smell funny out of my air conditioning, I stopped and look what is wrong with my engine it wasn't and I see white smoke out of my passenger side front wheel and I feel the heat is absolutely so hot!
I had to return back home! and look into it again and I have found that the caliper piston rubber seal had a hole which the damp have gone in and rusty the caliper piston cylinder.

I have remove the caliper piston, clean it with brake fluid and try to remove the lump rusty on the surface it become nice smooth and refit back in. Put all the pads back in and drove it was fine but when I apply the brake first time since refit it becomes difficult to acceleration like I was hold the brake at the same time as the acceleration!

Are the piston in caliper are suppose to move back in when release the brake pedal? do you think need new caliper? the new pads and disc it can't be a faulty?

Any suggest what is wrong please let me know cos I am confused why is stuck again after I have clean it.

Did you chip the rust off the pad carriers before you fitted new pads so the pads can move freely in their carrier?

 

[jackwhoo]

Did you chip the rust off the pad carriers before you fitted new pads so the pads can move freely in their carrier?

Did you change brakes on both sides of car?

 

[Theflyingpostman]

I have the new steel silver clip top and bottom where the pads sit on it and used copper grease.

 

[Theflyingpostman]

Yes I did both the driver side is fine and no hole on piston seal are function well as the passenger side.

 

[jackwhoo]

I have the new steel silver clip top and bottom where the pads sit on it and used copper grease.

Under the silver clip often rusts considerably, this reduces the space between the sides of the pad carrier, that makes the pads tight in the pad carrier , that can hold the pads against the disc causing over heat.
If when you fitted your pads they slipped in easy they are probably ok.
I can't remember the last disc brakes I changed that didn't need the pad carriers de rusting prior to fitting pads.


I recommend replacing caliper as the seal has had a hard time with the rust , plus you need to get a dust boot that doesn't have a hole.

Or get a new piston, new seal and new dust boot, ebay will help or possibly "big red" brakes in Worcester, they are on line and ebay

 

[Theflyingpostman]

My HGT diesel did have one but the petrol 1.2 that I had before I don't think I did have the carriers.

 

[Theflyingpostman]

Plan C: Take off again sand paper like one told me above and hopefully it works otherwise if is stuck again do I need new a caliper or pads???

 

[jackwhoo]

If the groove in the caliper the seal sits in is corroded then the piston won't retract after foot is removed from brake pedal.

Factoid alert.........Little appreciated fact it is the seal that retracts piston into Caliper after brake pressure released.

How awesome is that?????

 

[judderbar]

It might not be the piston causing the problems. 1. The caliper is sliding on rubber grommets with screwed in pins. So they should be lubricated.


2. The new pads do not fit very well into the rusted calipers. The inner pad is retained without needing to move in the rusted caliper but the outer pad slides insides the caliper. You might need to grind down the metal on the pads so the outer pad is not super tight in the caliper.


If all is well when the hard rubber square cut seal on the piston gets compressed from the inside of the caliper it should be able to push the caliper open again when the pressure is released and not be restricted by the tightness of the outer pads metal sliding against the caliper.

Thats my theory on this anyway.

 

[jackwhoo]

Plan C: Take off again sand paper like one told me above and hopefully it works otherwise if is stuck again do I need new a caliper or pads???

Bit of confusion here,

What I call the pad carrier is the metal frame that the caliper attached to.
Sometimes it's called caliper carrier.

Pad carrier is is what holds the pads,
Clean rust off (file) , apply copper grease to stop rusting again before fitting silver things. Pad should fit in silver things nice and easy.

You need to fix caliper any way because it will just rust again and cause more problems.

 

[AndyRKett]

Buy a new calliper, it really isn’t worth messing about with it, if the walls of the piston or the piston itself are scored or damaged all you are doing by sanding it or trying to clean it up, is open up the gap between the piston and the wall of the piston more and more till it will leak, it may already seep it’s just you’ve been pulling it about and trying to solve a different issue.

Honestly there is no point trying to fix it now, you need a new one. On the plus side these can be fairly cheap on eBay.

 

[varesecrazy]

Yep ..my suggestion of 'cleaning up' the sliding surfaces was aimed at making it function until your replacement arrives.

Like I said.. with no effective seal.. grit will keep doing this damage.