Please help!<o:p></o:p>
My 05 mk2.5 sport has a brake problem. The front nearside brake is binding and I just noticed it today. When i got home I checked both discs for heat and the n/s was definitely hotter than the o/s. <o:p></o:p>
Does this mean a near calliper or is there a cheaper way to fix it?<o:p></o:p>
Cheers
I am guessing you meant, a new caliper? If so the answer is no. All you need to do is take the caliper to pieces and clean the piston and cylinder and any other sliding parts. Lubricate the piston and cylinder with brake fluid and reassemble. You should clamp the brake pipe to stop all of the brake fluid from dripping out, before disassembling the caliper,and then when you have finished bleed the brakes.
Yup, I meant new not near don’t know what I was thinking.
Thanks for that. I’ll give it a go.
Hi Swerver
You may only have to take the guide pins out, clean and lubricate them, they are prone to some rusting in the carrier bores.
Also check to see if the rubber boots are ok with no splits or holes.
Failing that then like Pollyanna said strip the whole lot down.
Regards
Jeff
If the rubber is split is there a way to change it? Or is it then a case of buying a new one?
Hi Swerver
You have to remove the guide pin and move the caliper out of the way and the pull out the guide pin, then remove the boot.
Clean the carrier bore and boot groove and apply lubricating grease to the bore and boot groove, then assemble the new boot into the carrier boot groove and insert the clean guide pin. Do not over torque the guide pin bolt when reassembling the caliper to the pad carrier. If there is any run out on the caliper bolt lugs eg where the bolts go through into the carriers, this can splay the guide pins and cause them to bind inside the carrier bore.
This was a common fault with this type of caliper during manufacture and I spent many hours with other engineers trying to solve this problem. In the end we x rayed the calipers to see where this run out effected the position of the guide pin in the carrier bore.
The other common fault was a non concentric bore eg not round and to spec! this condition caused the caliper piston to bind when inserted into the bore during manufacture.
This often caused the piston to bind causing over heating and premature pad ware.
Have you checked to see if the caliper piston moves when the brake is slightly pressed?
Regards
Jeff
Cheers for that Jeff,
I’ve taken the caliper off and the boot wasn’t correctly seated and as a result some crap etc got in and the piston is no longer shiny and some of it is pitted.
I’ve managed to source a new piston and seal kit from http://www.brakepartssuperstore.org.uk very helpful guys. What kind of lubricating grease do you recommend?
Also the upper carrier bolt is stuck solid. Anything I need to keep in mind when rebuilding the caliper?
Thanks again.
IMO only lubricate with the brake fluid.
I use brake fluid for any components that are in direct contact with brake fluid in the braking system (e.g. piston seal) and red rubber grease for all other rubber components in the braking system.
Hi there
I use a grease called Klubber GLKO braking grease for lubricating the piston and can also be used for the carrier guide pins.It is hard to buy here in the uk and I bought mine from Germany some time back.
I know that when calipers are assembled during manufacture that the boot groove is also greased this helps the boot locate in the groove and provides a seal, many just use brake fluid so give the seal and the boot a good lubricating and aslo the piston, just be very careful not to chip the seal when inserting the piston!!! You should feel the piston meet up with the seal and then twist the piston gently to get the piston past the seal. Try to keep the piston straight when inserting and all will be fine, all sounds a bit long winded but it is easy to do and just feel it locate.
By the way if you live near to me I’ll do them for you, I live in Caerleon near Newport Gwent
Regards
Jeff