Brake pad fit, Won’t fit? Wrong pad for application? |
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Brake pad fit, Won’t fit? Wrong pad for application? |
Dion |
Mar 5 2021, 07:06 PM
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#1
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
I’m working on the front S calipers on the GT build and hit a snag.
The pads do not seem to be for this application. Wondering if different pads are warranted. I know these Porterfields have more meat on them. That could be the reason. The pistons are seated all the way in. (Fresh rebuild). I even tried moving them with a wooden dowel. They budge just enough to collapse seal slightly but when relaxed sit as they are. Am I doing it wrong? (IMG:style_emoticons/default/dry.gif) Help appreciated!! Note: no fluid in system yet. Any brake pad recommendations? Pics Attached thumbnail(s) Attached image(s) |
Front yard mechanic |
Mar 5 2021, 07:21 PM
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#2
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Senior Member Group: Members Posts: 1,205 Joined: 23-July 15 From: New Mexico Member No.: 18,984 Region Association: None |
Remove the backer plate ?
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worn |
Mar 5 2021, 07:33 PM
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#3
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can't remember Group: Members Posts: 3,290 Joined: 3-June 11 From: Madison, WI Member No.: 13,152 Region Association: Upper MidWest |
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Dion |
Mar 5 2021, 07:37 PM
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#4
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
I’m not against that if It won’t disintegrate as I destroy it:-)? I know it handles brake forces. It would prolly yield breathing space. But....
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bbrock |
Mar 5 2021, 08:20 PM
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#5
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
I be worried they would squeal like a mofo if you pulled the plate. No?
Let's turn on the Bat Signal and see what the super hero says: @Eric_Shea |
bkrantz |
Mar 5 2021, 08:49 PM
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#6
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914 Guru Group: Members Posts: 8,065 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
Sand the pads a bit?
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wndsrfr |
Mar 5 2021, 08:54 PM
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#7
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Senior Member Group: Members Posts: 1,436 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
Remove the backer plate ? (IMG:style_emoticons/default/agree.gif) Take off the backer plate & run them...after a bit of wear you can fit the plate back in if they're squealing.... Also it's the seals that are pushing the pistons a bit proud of being fully seated....so you could try slipping in the backer plate first then wedging the pad in--might work... |
Superhawk996 |
Mar 5 2021, 08:58 PM
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#8
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914 Guru Group: Members Posts: 6,469 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Are you sure you have the right rotor paired with those calipers? Looks too wide.
Not much space between the rotor and the caliper housing to account for lateral hub deflection. A bit hard to tell what the gap is between the rotor and the caliper housing from the photo's but looks tight. A rotor that is a couple millimeters too wide would explain why the pads don't fit and would need pad compound taken off to fit. If rotor is correct, I'd machine off pad material before I took off the backing plate noise isolator. Regardless . . . go with whatever Eric chimes in with. |
Dion |
Mar 5 2021, 09:29 PM
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#9
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
Are you sure you have the right rotor paired with those calipers? Looks too wide. Not much space between the rotor and the caliper housing to account for lateral hub deflection. A bit hard to tell what the gap is between the rotor and the caliper housing from the photo's but looks tight. A rotor that is a couple millimeters too wide would explain why the pads don't fit and would need pad compound taken off to fit. If rotor is correct, I'd machine off pad material before I took off the backing plate noise isolator. Regardless . . . go with whatever Eric chimes in with. Phil the rotor is one that was recommended for this set-up. I’d have to find the box for specs. Thanks. Hopefully Eric may chime in. Thanks Brent for alerting him :-) |
Dion |
Mar 5 2021, 09:36 PM
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#10
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
Remove the backer plate ? (IMG:style_emoticons/default/agree.gif) Take off the backer plate & run them...after a bit of wear you can fit the plate back in if they're squealing.... Also it's the seals that are pushing the pistons a bit proud of being fully seated....so you could try slipping in the backer plate first then wedging the pad in--might work... Thanks John. This is an option. Thanks guys. I was also checking the 911S registry. Seems like Textar was well received brake pad. Wonder if the dimensions would be different. The porterfields have a nice rep for performance/track combo. I’m not sure I’ll be doing “Track” events but mostly street/autocross. Maybe the Porters are just too large. Maybe just order the textar and see. Thinking out loud .... Appreciate the input as always. Keep the info coming. |
Superhawk996 |
Mar 6 2021, 09:51 AM
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#11
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914 Guru Group: Members Posts: 6,469 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
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worn |
Mar 6 2021, 10:27 AM
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#12
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can't remember Group: Members Posts: 3,290 Joined: 3-June 11 From: Madison, WI Member No.: 13,152 Region Association: Upper MidWest |
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robkammer |
Mar 6 2021, 11:04 AM
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#13
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Member Group: Members Posts: 195 Joined: 7-January 21 From: Vermilion Ohio Member No.: 25,049 Region Association: North East States |
Looks to me that the rotors are too thick. Here's a pic of a new Sebro rotor from Pellican. I'm redoing the system on my 74 but essentially back to stock.
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Montreal914 |
Mar 6 2021, 11:13 AM
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#14
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Senior Member Group: Members Posts: 1,675 Joined: 8-August 10 From: Claremont, CA Member No.: 12,023 Region Association: Southern California |
S was running vented rotor...
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Dion |
Mar 6 2021, 11:15 AM
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#15
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
Measured the vented rotors. They are 20.3mm thick.
I’ll massage these pads. I will probably order different pads. I’ll call Eric on Monday. Thanks fellas. |
mepstein |
Mar 6 2021, 11:55 AM
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#16
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914-6 GT in waiting Group: Members Posts: 19,518 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
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Superhawk996 |
Mar 6 2021, 11:56 AM
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#17
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914 Guru Group: Members Posts: 6,469 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Yup - you're good on rotors.
It's likely the noise isolator adding thinckness. Back in 70's - pads didn't usually have noise isolators. Just the bare backing plate. Noise fix was often "brake grease". Even if there was a isolator, they were often clip on affairs with limited effectiveness. Modern bonded constrained layer noise isolators are more way more effective than brake grease and clip on isolators of old. You would think Porterfield would have removed enough pad compound to offset the added thickness of the isolator. We used to machine pad compound all the time to insert thermocouples and/or for custom rotor setups. Easy to keep it all square with a mill. Can be also done sucessfully with careful measurement, marking / guide tape, and use of belt sander to keep the pads square and level. Use shop vac to suck up all the dust as you "sand" the pads. |
Dion |
Mar 6 2021, 12:02 PM
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#18
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
(IMG:style_emoticons/default/agree.gif) Thanks Phil. (IMG:style_emoticons/default/beerchug.gif)
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Eric_Shea |
Mar 10 2021, 09:34 PM
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#19
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PMB Performance Group: Admin Posts: 19,289 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Looks like a 24mm Carrera rotor. S-calipers take 20mm. Hard to tell from pictures but that rotor groove appears VERY tight.
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Dion |
Mar 10 2021, 10:23 PM
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#20
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RN Group: Members Posts: 2,793 Joined: 16-September 04 From: Audubon,PA Member No.: 2,766 Region Association: MidAtlantic Region |
@Eric_Shea Thanks for checking in. Haven’t had a chance to ring ya.
Here’s a pic of caliper measurements. 20.3mm Sebro. I ordered some “ate” pads from your store just to see any pad thickness variation. Thanks mate. Attached thumbnail(s) |
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