(T) Problem Fitting Brake Pads

Hi there,
this is my first thread, i browse here quite a lot, but i have never signed up, i prefer to just read, now i have a problem though!

My car had its MOT and service (3 year, ~34K) about 8 days ago. The brake fluid was changed at this time but i was told my pads were 80% and needed replacing. Its a Seicento Sporting, 51 plate, by the way

I bought some pads, and have fitted them this afternoon. Now though, the travel on the brake pedal is almost to the floor. It was fine before the new pads.

When the engine is off and i pump the pedal a few times it goes hard. But when its running the travel is almost to the floor.

I kept an eye on the fluid as i pushed the pistons in, and have made sure its topped up ok. Is there anything else i could have messed up while doing it?

I guess the fronts just need bleeding, but i wanna make sure its nothing easier. I have bled brake on a real old car, i guess the principle would be that same? Why would they need bleeding after changing pads though? Surely no air should have got into the system anyway?


Cheers for any advice and thanks for having me

Kristian

Changing the pads has probs not caused the pedal to travel to the floor, it was most likely to be when the fluid was changed . Bleeding the brakes would be worth while doing. Sounds like when it went in for the service they haven't bleed them very well. You might find it useful to bleed the system a few times, once soon and then again in a few thousand miles, this will help to eliminate the air in the system.

HTH

David

Well they were absolutly fine for the 10 days after the service, but i guess they probably do need bleeding agian, hopefully i can get away with just bleeding the front which wouldn't take too long.

I have DOT4 fluid already, not the Brand FIAT use, would it be best to not mix the brands?

Cheers,

Kristian

Shouldnt make any difference really, cos the DOT4 standard's there to make sure all fluids behave to the same characteristics...

Just bleed the system so the fluid is clean (new) throughout, and theres no dirty stuff (old, discoloured) in there!

How did you push the pistons back?

Weird problem, wonder what it could be?

Liam

Hi,
Did you change the discs when you changed the pads..? if not were there any ridges on the outer and inner edges of the disc, this causes the pads to stand off the face of the disc untul they have bedded in, a way of accelerating the bedding in process is to file a chamfer on the inner and outer edges of the friction material on the brake pads, as long as the chamfer is bigger than the ridge, you shouldn't get this problem.

Hope this helps.

Paul T

Ridged discs would not cause the pedal to go long. My only thought is that pushing the pistons back in has turned a seal in the master cylinder.

Cheers

D

Thanks D, in my earlier post that's what I wanted to say, strnage how just fiting pads should do this, something amiss in the fiting process.

Liam

Thanks for the responses!

I pushed the piostons back by taking out the old pads, putting one of the new ones in on the piston side, closing down the caliper and then pulling on the unit, which slowly pushed the piston back, the i raised the arm a gain, put the second pad in, and colsed/locked the arm as i should.

I though it was odd that any air got in, i can see no leaks at all anywhere, which is good. Its too dark to do anything for the rest of the week, so i'm gonna bleed the system on saturday. Hopefully that will sort it, and not have to worry about changing seals or master cylinders


Whith regards to the disk, they were very sligthly worn, about 1/4mm or less, but once the new discs bed in i don't see this as a problem, or cause the long travel.

Cheers for all your ideas, and wish my seals and bleed attempt good luck

Was there anything wrong with my procedure, with regards to pushing the cylinders back? I can't see naything wrong with doing it that way.


Cheers 4 ya time,

Kristian

Ps. If wish i hadn't cleaned some of the brake dust, else i could have put the old pads back, and blamed the garage who serviced it, nevermind eh!

Doesn't seem anything wrong with your method, I tend to use a large pair of pipe grips to retract pistons. It is usually shocks to the system that cause seal problems.

Cheers

D

Hi,
Did you slacken off the brake fluid reservoir cap before you pushed the pistons back, if not this could have inverted one of the seals in the servo..hope not though, cos I hate stripping servo's down, brake fluid gets everywhere.

Thanks
Paul T

Yep, i did that, took the cap off, pushed the piston back, drew off the excess with a clean syringe. Made sure afterwards it was at the correct level. Still went to the floor.

I heard of "pedal to the metal" before but i i don't think im liking this pedal hitting the metal

Kristian

Well, no joy im afraid

I bled the brakes, and the pedal still travels to the floor when the engine is running, but stiffens up when its off. I don't want to mess up any more so am gonna try and get it into a garage and sorted. Not going to the dealer for it though, hopefully find somewhere cheaper. Also i noticed the fluid was quite dark and dirty compared to the new stuff, and the nipples has seised, and the caps were perished and caked in dust and dirt. To me it doesn't even look like the fliud was changed in the 36K service, but as im no proper mechanic i can't be sure, and so can say nothing to them about it.

Cheers for your help eveyone, any more ideas that are easy to try this weekend and im all ears

Laters,

Kristian

Mines was dark too but to totally clean it you need to blled he rear brakes too which will likely lead to finding dodgy cylinders or breaking the nipples off.

Liam

Well, just in case anyone is interested int the progress, Kwik Fit had it today, they flused all the brake fluid, to get rid of any air and gunk. They also played withthe handbrake cable (not sure why?). They siad they got pressure for a bit but then it went again to how it was before. They said they think its the master cylinder, but they couldn't replace that for me. It's now back with the dealer to be looked at which im sure is gonna cost a hefty packet of ££!!!! Hopefully they can fix it soon though as im can only borrow a car till tommorrow, then its a 30 mile push bike ride to and from work

Top marks for Kwik fit though! Althought they couldn't fix it, they made no charge for trying I thnik thats exellent!

Lets see what the dealer says tomorrow!

Laters,

Kristian