sforster Posted April 10, 2009 Report Share Posted April 10, 2009 On my old tr3a I had a problem when the brakes got hot, they would squeal. I solved this by fitting green stuff pads. On the car I have now, I have a similar problem when the brakes get hot as the car is driven quite hard around mountain roads. I tried fitting green stuff pads, this just exaggerated the problem. I've run the car with and without the restrictor valve fitted with no difference. The brake disks are clean, slightly pitted but without wear to the outside edges. The micrometer proved the disks straight. The pads are resonably new with plenty of life in them. I have noticed the pads rattling a bit on the disks whilst driving, though a quick dab on the brake pedal usually stops this. Any suggestions would be greatfully received. Many thanks Simon. Quote Link to post Share on other sites
stuart Posted April 10, 2009 Report Share Posted April 10, 2009 On my old tr3a I had a problem when the brakes got hot, they would squeal. I solved this by fitting green stuff pads.On the car I have now, I have a similar problem when the brakes get hot as the car is driven quite hard around mountain roads. I tried fitting green stuff pads, this just exaggerated the problem. I've run the car with and without the restrictor valve fitted with no difference. The brake disks are clean, slightly pitted but without wear to the outside edges. The micrometer proved the disks straight. The pads are resonably new with plenty of life in them. I have noticed the pads rattling a bit on the disks whilst driving, though a quick dab on the brake pedal usually stops this. Any suggestions would be greatfully received. Many thanks Simon. I take it you have applied plenty of copperslip to the rear of the pads before fitting. It may be that the pits are getting contaminated with pad material which wont help. Is there enough depth left on the discs for a light skim. You do seem to be suffering from pad knock back as well if you can hear them rattling. Do you find you have a lot of travel on the pedal every time after sharp bends?. There is a kit to stop that now consisting of a distance piece and shims to keep the bearings in line. Stuart. Quote Link to post Share on other sites
sforster Posted April 10, 2009 Author Report Share Posted April 10, 2009 Hi Stuart, Thanks for the reply, yes I used plenty of copperslip behind the pads. The brakes effectiveness is fine, there is no excessive pedal travel. The pittinig I mentioned is in my opinion very minor the odd pin hole, not craters. Simon. Quote Link to post Share on other sites
RogerH Posted April 10, 2009 Report Share Posted April 10, 2009 Hi Simon, the new Green Stuff pads have a self adhesive teflon pad that goes on the brake pad rear face. This very effective in stopping brake squeal. The pads need to be free in the caliper to stop them rattling. The pins need to be free on the pads. Have you clocked the discs to ensure they are not warped. If they more than a few thou out they may cause 'squealing' /judder Roger Quote Link to post Share on other sites
sforster Posted April 10, 2009 Author Report Share Posted April 10, 2009 Hi Roger, The disks are no more than 0004" out, I would have thought this is considered straight on a car this old? Simon. Quote Link to post Share on other sites
Paul Down Posted April 10, 2009 Report Share Posted April 10, 2009 Hi Roger,The disks are no more than 0004" out, I would have thought this is considered straight on a car this old? Simon. The discs may be true overall but what is the run out on rotation. A figure of 0.0004 " would be highly unlikely! Quote Link to post Share on other sites
sforster Posted April 11, 2009 Author Report Share Posted April 11, 2009 Hi Paul, If I understand you correctly when you say "run out on rotation". I used a dial gauge set up on a stand pressed to the disk and rotated the disk, the overall inperfection on a full rotation is no more than.0004" Simon. Quote Link to post Share on other sites
RogerH Posted April 11, 2009 Report Share Posted April 11, 2009 (edited) Hi Simon, here is a long shot. If it is squeal as opposed to judder then the squeal is generated by vibration of the pad on surrounding structure (caliper). The pins holding the pads in place should be a loose fit - they simply stop the pads from flying out. The pads should be a loose(ish) fit in the caliper - they must be free to move. The leading edge of the pad should butt up against the caliper. During braking the pad is forced against the caliper as the pads grip the disc, and shouldn't squeal. However if the disc has an exposed grain structure this may give different level of grip as it rotates and vibrate the pad - have a look at the disc and see if there is different/odd colouration when held against a light source, this may require grinding. Otherwise have a look at the pads and see if they are touching the caliper other than at the leading edge. If so file the pad steel backing to relieve the touching. My head hurts now Roger Edited April 11, 2009 by RogerH Quote Link to post Share on other sites
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