440 sticking front brakes

Hi
New To This Forum I Have A 1994 440 1.6 With Sticking Passenger Side Front Pads , It Seems To Be The Cylinder ,the Disc Is Getting Hot , Any Help On The Matter Much Appreciated

Cheers

Paul

Hi,

Most likely one of the following things is causing your brakes to bind:
- the caliper has seized to one or both guide pins, preventing the outer pad from retracting from the disc.
- the caliper piston has seized inside the caliper cylinder preventing the caliper from retracting
- the brake hose has worn out inside creating a kind of "one way valve" preventing the the fluid from returning back up the hose

Note that the last of these points is more difficult to detect by looking, but if the brake cannot be free'd and you open the bleed screw to let some fluid out and then the caliper retracts then replace the rubber brake hose.

Good luck,
Pete

CHEERS PETE
I WILL TRY THIS
CAN YOU BUY A SEAL KIT FOR CYLINDER?
AND IF ITS THE CALIPER HOW CAN YOU TELL IF ITS DONE FOR ITS THE LUCUS TYPE






THEY HAVE BEEN CLEANED UP AND NEW PADS FITTED SINCE

[Lou Ferrigno]

I am not sure whether seal kits can be bought for this model but try : Brakes International Ltd, Rochdale - tel no. 01706 666999 They provide a postal service and are extremely helpful.

Incidentally, what an excellent reply you got from PeteS40. This is what these forums are all about.

Originally Posted by martinv

Incidentally, what an excellent reply you got from PeteS40. This is what these forums are all about.

Cheers for that

Incidentally, I rarely venture into technical forums other than for my car (S40) but I just spotted this one in the "latest posts" list. The forum is so popular that if you only check once a day you are normally faced with 200+ new posts... so not exactly practical to wade through each one!

Re. the technical question, one other obvious thing i kind of forgot to mention is that the pads can stick to the carriers. Make sure the contact surfaces are clean, if necessary use abrasive paper or a small file to file off the crud on the pads and/or the carrier contact surfaces and apply copper slip so that - even when hot - the pads are able to slide back and forth to the disc without sticking to the carriers or the caliper etc. Cleaning everything up is obviously a simple thing to do and a good first step and this might well sort it all out. Make sure everything that is supposed to move can move freely.

Re. specific questions on calipers... yes volvo show a seal kit is available, likely the piston is also available separately so you could repair the caliper although you may find fitting a new caliper is the best (and easiest) solution. Seal kit would be a dust seal and the fluid seal I would think. To tell... well if you decided to get the kit and remove the piston you may well see traces of rust on the piston and/or the cylinder which you can remove with very fine abrasive paper but if scratched/scoured too much then replace piston or if on cylinder, replace the whole caliper.

To tell if likely to be the caliper, well you can often tell by eliminating the above things I listed and then by the feel of the brakes... if you clamp the hose to the affected caliper and the feel does not harden up it is likely the piston is sticking. If you remove e.g the outer pad and try and activate the brake and the piston clearly won't move then it is def. stuck. Likewise if you wind in or out the piston and it won't budge or is rough then it can feel obvious. If the brake is binding so bad like you suggest and it is the caliper then likely the piston cannot be retracted in which case it sounds like easy to tell.

But as I say, start by pushing back the piston (which you will likely have to do in order to get the pads back in), clean it all up and make sure contact surfaces are not causing sticking. Brake cleaner spray is useful as a degreaser.

Pete

P.S: Weird how your camera makes rust look pink!

MANY THANKS FOR THE HELP LADS
GOT ANOTHER CALIPER AND FITTED IT ,
SEEMS TO BE A NO STICK SYSTEM AGAIN.