Bassman 1 Posted October 17, 2007 Hello, Almost finished painting and refurbishing the calipers I bought from a 307HDi. Re-fitted the pins into the yokes that the calipers bolt to and subsequently slide on when the piston is extended and relaxed. I noticed on dis-assembly that on each caliper, one of the pins has a ribbed rubber seal on it. When re-fitting, although I have lightly re-greased them, after a day or so, the pins with the rubber seals on seem to have almost seized and it takes a fair bit of effort to pull them out again. The others without the seal are fine as I would expect. Am I doing something wrong? What are these seals for and do I need them? If they are supposed to cause one end of the caliper to have less movement, won't this warp the discs? (I had this problem on my 405, but this was due to the outer seal perishing and the pin rusting solid. The 405 doesn't have this inner ribbed seal.) I have drawn a little picture in powerpoint to illustrate the issue which may help. Thanks Rob Share this post Link to post Share on other sites
Bassman 1 Posted October 18, 2007 (edited) A search on Google returned this: "If the pin is metal with just a loose rubber boot to keep the s*ite out then i use regular Lithium grease or prefered is copper grease. if its a rubber pin (a metal pin with a tight rubber anto squeal covering) then i use a silicon spray lubricant as i find regular mineral grease will cause the rubber to swell." Had another look and found this useful link which confirms it: Brake Lubricants It suggests a MOS2 style lubricant (CV Joint / Clutch bearing grease which I was using) as it is a high-temperature grease and is suitable for general brake use such as the pins, but a silicone-based product for rubber and plastic parts in the calipers (and wheel cylinders for drums). As my pins have a rubber anti-squeal sleeve then I will get some silicone on the way home. Everyday is a school day! Thanks Rob Edited October 18, 2007 by Bassman Share this post Link to post Share on other sites
pug_ham 242 3 Cars Posted October 21, 2007 Copper grease isn't preferred acording to tjhe refurbished ones I'bought a year or so since. It can cause uneven wear to the sliders due to the small metal particles in it. I was advised just to use decent lithium grease. Graham. Share this post Link to post Share on other sites
brianthemagical 1 Posted October 23, 2007 check the sliders are straight and true. my rears were as you describe and the back mounting plate was warped. Share this post Link to post Share on other sites
Bassman 1 Posted October 23, 2007 Copper grease isn't preferred acording to tjhe refurbished ones I'bought a year or so since. It can cause uneven wear to the sliders due to the small metal particles in it. I was advised just to use decent lithium grease. Graham. Yes I wasn't going to use the copper grease as I thought the same. I am currently using a lithium grease which is the MOS2 grease but it is this that is causing the two sliders with the rubber sleeves on to stick as the sleeves swell. The other two sliders are perfect with this grease. Should hopefully have the time to pull the sliders out this weekend and clean out the lithium grease on the two sliders with the rubber sleeves and try this silicone lubricant instead. Hopefully this will stop the swelling and then I can get on with fitting them. Had a good day today as my minidisc player in my 405 had packed up. Took it all apart, checked all the solder joints and saw nothing dodgy. Re-assembled in hope ... ... and surprise, it was still faulty. Decided, in my frustration at having to drive home for 40 minutes in silence, to try some persuasion with my fist and hey presto, music! Hopefully this "Fonz style" repair will see me through another 12 months of motoring. Share this post Link to post Share on other sites
