(G) Sticky Brakes

Hey, my uno front callipers stick really badly in cold weather, sometimes so i cant get over 40 mph. i have tried taking them off and oiling them, but this solves the problem only for a few weeks then they start seizing again. Is new callipers the only way? Is it worth changing em for new ones as car is beaten up and done 110k miles? would appreciate your thoughts people.

The car goes 100.000 miles more.

Usually the rear brake shoes sticks after hanging on the hand-brake for a while, but I've never heard of it on the front. New calipers, brake shoes and brake discs is a possible solution, check the bearings for wear at the same time.

Morten.


Abarth alloys. Inter Alloy lowering. Phoenix Gold & Kenwood audio. Abarth steering wheel. Insane Dalmatian door and seat refurnishing

Projects: K&N induction kit, racing seats, exhaust, window tinting.

Hi Phil.

I have the same problem, so I'm also interessted in a solution. I had below zero for weeks now so maybe my car get's better when the weather gets warmer.

My mechanics did not believe me when I said it was the front wheel, rear wheel is common on every car due to the handbrake.

My plan is to wait until it gets warmer and try to drive for a while to see if the breaks unlock. (I had problem in the summer as well with a small almost not noticeable lock in the wheel, so I guess a little ice and more rust made it stuck, driving around hopfully solve it)

Have you tried a more effective and longer lasting mean of lubrication? Such as copper grease or some other type of anti seize, high temp compound... that would be my 1st bet. Note that if the brakes r sticking, your discs will probably warp (if they aren't warped already) in no time.

Goncalo D.

Thanks for your advice, i might try and get some different types of lubricant as i was using wd40 which is probably not the best and would be easily washed away by road spray. Weather recently become a bit milder and problem is no where near as bad. Something to do with temperature i reckon. Thanks again

Front caliper design is a bit crude but simple..main reason for sticking is that the caliper slides in two sort of open L shaped retainers....these are plated steel when new and the caliper body is aluminium add salt and water and we have a great place for bi-metalic corrosion..
Remove little retaining circlip and drive out the slide pins,outwards,( used a side of a screwdriver or a small flat bar between pin and hammer!!!) file off rust and alloy corrosion and then wire brush and clean caliper body where slides sit. Apply a little coppaslip grease to mating surfaces and this should help. It needs doing about every 6 months. If the slides are very bad you could try getting new ones, you used to be able to, but last time I tried i was told only available as part of new caliper...and I suspect a pair of these may well cost more than most unos are worth..hope this helps

There are two ways I know of which the caliper can sieze up:

the one above described by Peetie, which gives you half braking effort, odd wear on the pads (and wheel bearings), and tends not to drag too much as the single piston still operates normally on one pad.

the other one is probably what you have, which is where the piston sticks inside the bore of the caliper, and doesn't ease off pushing the pad when you take your foot off the brake.

My limited experience of the latter is that it tends to happen when the pads are worn down a fair bit, and you can achieve a temporary relief from the problem with new pads: the pistons don't get out to the sticky bit.

I have known people who claim to have dismantled and repaired wheel cylinders - and lived [:0] - but I'm not bold/confident/silly enough to have tried it.


Regards

John H


P.S. It might be worth asking "Alfanige" if they have some calipers in the "bankrupt stock"

http://www.fiatforum.com/forum/topic.asp?TOPIC_ID=6364

just take you breaks off, they are for pussies anyway

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Yes John H you are right on that. I have had that problem too.
I have rebuilt calipers but would not recommend it on safety grounds and also because once the caliper is that far gone it will be very difficult for the new seals to work on dirty or worn components success rate on old calipers about 60% but remember a seal kit is about £8 or £9. I have pulled back the dust seal and lubricated with wd40 and that can work but I don't know what that stuff would do to the seals long term.
Try the guide pins first with new pads and if that dont work see if you can source a new caliper.

Thanks for all your help. I took the callipers off, applied pleanty of copper grease and then fitted some new pads. This seemed to have solved the problem completely. Thanks guys :)

Well done :)

Hi guys, just come over from the Doblo forum to share an experience.
I used to have a Uno & experienced a problem with front brakes binding.
I'd had the car for ages with no problems, the day before I'd done 200 miles on the motorway. I'd just driven three miles & it was as though the engine had no power, it was revving away but the car wouldn't move & I noticed smoke coming from the front wheels - the disks were glowing .

Breakdown lifted car to their garage where they replaced the front pads & said the disks might need replacing as well.

Anyway.
could never get to bottom of the problem - bought new master cylinder, new wheel cylinders, new disks, new pipes - basically, a whole new front end on the brakes, chucked the better part of £700 at it (tried 2nd hand stuff first, it didn't solve it).

I was at my wits end.

Spent the better part of a day googling the problem & asking on Uno forums around the world & eventually one guy came back to me later in the week with the same problem on his Panda.


The brake switch.

It screws into the mounting bracket over the pedal, a locking nut then holds it firm - for whatever reason, the switch screws itself in closer to the pedal.
As the pads fly extremely close to the disk under normal conditions, the switch body not allowing the pedal to fully return home means the pads then sit closer to the disk until there comes a point where the pads get warm, the warmer they get, the more they expand & the closer they get to the disk - the closer they get to the disk, the hotter they become causing them to expand even more...

Result!

10 mins under the dash & it was sorted - unscrew the switch & ensure the locknut was tightened.

Still, the new brake system gleamed