Can't get Rear Calipers Back On????

[XLR8]

I'm changing my rear rotors and pads on my 97 Cobra and for the life of me can't get either rear caliper back on. The caliper is hitting the pads. I've triple checked my parts to make sure they are correct and they are. I've retracted the pistons as far back as they will go and still they won't fit. Any ideas would be greatly appreciated. Is it possible the pistons aren't retracted all they way? I removed the cap to the brake reservoir to relieve any pressure. Thanks.

[RedSN]

Yeah, sounds like the piston is just not retracted far enough. It can be really stiff sometimes. I've cursed at it many times.

[tulowd]

pistons need to be screwed into the housing using a tool or in a pinch some properly sized needle nosed pliers and a lot of push with no slip. https://www.google.ca/search?q=brake+piston+retraction+tool&biw=1280&bih=530&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi-oanwrKXMAhWFvIMKHanYDyMQ_AUIBygC#imgrc=8Tb5SWuZ5iO ExM%3A

The pads can come 2 thicknesses 14 and 17 mm I believe- if the rotors are too thick with thick pads it may not work.
Measure the pad and rotor thicknesses and compare to the caliper openings.
Stock Cobra rotors are 11.65" dia x 0.71" thick.

After 5 track days:

http://i1245.photobucket.com/albums/gg582/tulowd/87%20Vert%20TU%20LOWD2/IMG_1200_zps1saplkmn.jpg



From TheCorral:

Old 09-09-2003, 10:09 PM Geezer (http://forums.corral.net/forums/members/55789-geezer.html)
Registered User

Trader Feedback: (0 (http://forums.corral.net/forums/itrader.php?u=55789))
Join Date: Aug 2003
Location: Tejas del norte
Posts: 468



The GT front rotor (http://rover.ebay.com/rover/13/0/19/DealFrame/DealFrame.cmp?bm=293&BEFID=96477&acode=316&code=316&aon=&crawler_id=482306&dealId=JEinOZbDgT5IIv_4b0dVSg%3D%3D&searchID=&url=http%3A%2F%2Fwww.americanmuscle.com%2Fdba-4000-t3-slotted-front-1516gt.html%3Futm_content%3Ddba-4000-t3-slotted-front-1516gt%26utm_campaign%3DShoppingFitmentV1%26utm_so urce%3DShopping_com%26utm_medium%3DShopping%26AMID %3Ddba-4000-t3-slotted-front-1516gt-2016-GT%26year%3D2016%26model%3DGT&DealName=2016%20Ford%20Mustang%20GT%20DBA%20DBA421 64S%204000%20T3%20Slotted%20Rotor%20-%20Front&MerchantID=482306&HasLink=yes&category=0&AR=-1&NG=1&GR=1&ND=1&PN=1&RR=-1&ST=&MN=msnFeed&FPT=SDCF&NDS=1&NMS=1&NDP=1&MRS=&PD=0&brnId=2455&lnkId=8070676&Issdt=160421051550&IsFtr=0&IsSmart=0&dlprc=195.77&SKU=SMdba-4000-t3-slotted-front-1516gt-2016-GT) is 26mm/1.03" thick & 276mm/10.9" in diameter. The Cobra front rotor is 28mm/1.1" thick & 330mm/12.9" in diameter. The GT solid rear rotor is 14mm/0.55" thick & 266mm/10.47" in diameter. The Cobra vented rear rotor is 18mm/0.71" thick & 296mm/11.65" in diameter. To fit the larger rear Cobra rotor (http://rover.ebay.com/rover/1/711-53200-19255-0/1?toolid=10029&campid=CAMPAIGNID&customid=CUSTOMID&catId=6000&type=2&ext=360723246835&item=360723246835), you will need the Cobra caliper adapter bracket & the Cobra brake pads (which are thinner to allow the OE GT caliper (http://www.amazon.com/dp/B019NUFX0Y) to be used w/the thicker Cobra brake rotor).

[XLR8]

Yeah I've been using the tool and have screwed them in as far as they will go, I think. I'm not sure how to tell when they "bottom out" They keep spinning but they don't seem to be retracting anymore. I'll measure my rotors and pad thickness, thanks for the info.

[Ponyryd]

When they're all the way in they should be flush with the housing or very close to flush. You need to apply some decent pressure to get them in all the way, the good retractor kits have a push flange that applies inward pressure while turning in.

[XLR8]

^^^^OK they are not totally flush. I just bought that little square cube that attaches to a 3/8" drive. Maybe I'll go buy the one that applies pressure. Thanks.

[ZR]

Sure you've got Cobra vs GT rear pads? GT / V6 version are thicker.

[XLR8]

According to the part number on the box they are Cobra. Makes me wonder.

[ZR]

You've got vented Cobra rotors as well?

[XLR8]

Rotors are not vented, they look just like the ones that came off. Should they be vented?

[ZR]

Cobra rear rotors look like this (vented = vanes running down the center).

http://s7d4.scene7.com/is/image/Turn5/53058?$subcat250x187$




GT / V6 looks like this (solid with no vanes)


http://s7d4.scene7.com/is/image/Turn5/53103?$prodpg640x480$

[ZR]

While rotating the piston, are you applying pressure inward?

[ZR]

Can you take a pic of

-old rotor
-new rotor
-new pads beside old pads (from edge showing thickness)
-caliper piston position (from ege showing how far retracted)

[Ponyryd]

^^^^OK they are not totally flush. I just bought that little square cube that attaches to a 3/8" drive. Maybe I'll go buy the one that applies pressure. Thanks.

They should be close to flush. CTC should have the tool to borrow, where did you get the rotors?

[XLR8]

OK sorry ZR they are vented, it thought you meant the surface of the rotor. Yes I'm applying force as I turn them in. I bought them from a local auto parts store here in Woodstock. I'm going back to them tomorrow with the parts just to make sure they are correct.

[ZR]

Ok so you need the thinner Cobra pads that match the vented rotors.
You should be able to Google search part numbers on the web to confirm.
If you bought Raybestos or similar jobber replacement pads, have seen it time and again where they only show one part number for GT-V6 and Cobra or when they do show a different pad for the Cobra it's too thick to install on a Cobra.

[XLR8]

Hey ZR thanks for all the help. Turns out the pads were wrong. I brought them back and switched to another brand and they were thinner and went on with no issues. Thanks again.

[ZR]

Good on you for staying the course and getting in handled.