Is the backing plate really necessary?
I'm trying to install Hawk HT10 and there is no way I can fit the pads in with the backing plate. The piston is fully retracted. The pads will go in w/o the backing plate.
+1What you are referring to is not a backing plate, but a shim. as you are already aware of its purpose is for noise reduction. They are not necessary for proper braking (the steel BACKING PLATE protects the pad material from being crushed by distributing the load).
It has no other function. I had to work to get my Pagid Blues to fit with the shims. but its worth it to me (less noise in the long run.) I also put brake goo between the backing plate and the shim, and where the shim contacts the caliper/piston.
Actually, heat transfer would be reduced because the contact between the shim and backing plate is minimal through the paint and the adhesive. The changes in material affect thermal contact conductance.+1
The shim is for noise reduction. The only way the shim would make an appreciable difference in keeping heat from the piston would be if it was made from stainless, or better yet titanium. If it came with your brake pads I highly doubt it is either.
Actually, heat transfer would be reduced because the contact between the shim and backing plate is minimal through the paint and the adhesive. The changes in material affect thermal contact conductance.
Yes, it calls to mind why an insulating shim needs to be of any specific material; the simply fact that there is a shim is half the improvement....
My OEM front brakes just had a thin film bonded to the front pads (no shims), nothing on the rear pads. On my first pad change, I used this: <a href=http://www.crcindustries.com/auto/content/prod_detail.aspx?PN=05016&S=N>CRC Brake Quiet</a>. You apply it in a thin film to the backing plate, let it dry before installing the pads, and it's supposed to reduce brake squeal.
Under certain circumstances, the brakes still squealed... I think it's more important to lubricate the contact points between the backing plate and the pistons/caliper guides than to have a shim or film... I use this: <a href=http://www.crcindustries.com/auto/content/prod_detail.aspx?PN=05351&S=N>Brake Caliper Grease</a>. Apply "liberally" (especially you, Gil ), but make sure not to get any on the rotor or the pad's friction material.
EDIT: I just installed Hawk HT-10s a few days ago... the pads didn't look like the ones in your photo (and they had that annoying dimple on the backing plate: http://www.lotustalk.com/forums/f91/question-those-who-have-put-hawk-ht-10-a-73089/).
rotflMy photo above was for illustrative purposes. My HT10 actually had an annoying ZIT-looking thing sticking out that I had to file down.
My OEM front brakes had a "thin film" but if you stick a small screwdriver in it, it pops up and it's actually a shim. I re-used it on Pagids, and now I'm trying to reuse the shim on the HT10s and put Blue Permatex in-between, but it will not work.
Okay, so here's an update. I'm running the HT10s w/o the shims to wear it down a little so that I can slip the shim in later on. Hopefully, I can do this soon, because the brakes squeaks like a :no: at low speeds light braking. :sad:rotfl
I just dug out my OEM pads, and sure enough that thin film <b>is</b> the shim... I didn't try to pry it off at the time since it seemed to be very tenaciously bonded on. Maybe I'll try to pry them off and slip them onto the HT-10s...
rotflOkay, so here's an update. I'm running the HT10s w/o the shims to wear it down a little so that I can slip the shim in later on. Hopefully, I can do this soon, because the brakes squeaks like a :no: at low speeds light braking. :sad:
Did you use brand new rotors? I was using brand new rotors with full thickness and it would not fit with the shim plates on. I had to run without shims for awhile before I could go back and put the shim plates back on.Just a bit of an update...
Yesterday I put in a new set of HT-10s... after filing off the "dimple", I had no problem installing the new pads with the OEM shim plates... they dropped right in, without having to wear the front pads down at all.
On slightly different subject... is anyone able to change the rear pads without removing the calipers if you have both wheel studs and a two-piece rotor? Seems there's no way to wiggle the pads out otherwise...
My rotors were new (~1000 miles), but they are Sector111 UltraDiscs, which may be just slightly thinner than a new set of factory discs. The pads and shims actually fit in quite easily :shrug:Did you use brand new rotors? I was using brand new rotors with full thickness and it would not fit with the shim plates on. I had to run without shims for awhile before I could go back and put the shim plates back on.