New rear rotors won't install - caught on rear drum friction material

billmidd08 · 07-31-2020, 03:02 PM

So I started a project of refreshing my rear brakes by flushing fluid, replacing my ****ty wheelstuds with ARP studs along with installing new centric high carbon rear rotors and new Project Mu rear pads all at the same time.

Flush is done, new wheelstuds are installed, but am encountering some issues on the rear rotors.

Trying to get the new rotor mounted on the new studs and found it will not clear the ebrake drum. In fact, it won't fit my old worn rotor back on either at the moment, tried it just for ****s and giggles and to make sure my new rotors are the right size (they are).

I turned the star adjuster at the bottom of the drum to full loose but I'm not sure it's actually shrinking the circumference to get more clearance, the edge of the drum friction material is still barely catching the inner rotor lip on full loose. I've turned the star adjuster up and down a good chunk of its range a few times... and nothing visually looks out of place to me.

Does anyone have a rear drum tips/tricks? ...or a manual if I need to actually disassemble the ebrake drums.

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dpetro1 · 07-31-2020, 04:43 PM

Quote:

Originally Posted by billmidd08

So I started a project of refreshing my rear brakes by flushing fluid, replacing my ****ty wheelstuds with ARP studs along with installing new centric high carbon rear rotors and new Project Mu rear pads all at the same time.

Flush is done, new wheelstuds are installed, but am encountering some issues on the rear rotors.

Trying to get the new rotor mounted on the new studs and found it will not clear the ebrake drum. In fact, it won't fit my old worn rotor back on either at the moment, tried it just for ****s and giggles and to make sure my new rotors are the right size (they are).

I turned the star adjuster at the bottom of the drum to full loose but I'm not sure it's actually shrinking the circumference to get more clearance, the edge of the drum friction material is still barely catching the inner rotor lip on full loose. I've turned the star adjuster up and down a good chunk of its range a few times... and nothing visually looks out of place to me.

Does anyone have a rear drum tips/tricks? ...or a manual if I need to actually disassemble the ebrake drums.

Can you compress the shoes by hand with the adjuster loosened?
The return springs may be holding the shoes out.
Grease everything up to make sure it's all moving freely.

billmidd08 · 08-01-2020, 02:38 PM

Nope, definitely not able to compress them by hand with the adjuster loosened. Will see if I can unfreeze it.

*EDIT*

UPDATE: after brake cleaner and grease was able to brake everthing free and get some wiggle room to successfully get the rotor mounted.

2slofouru · 08-01-2020, 03:32 PM

You may have purchased normal wrx rotors that have a smaller ID for the e-brake shoes. That would prevent them from sliding over the larger STi e-brake shoes.

Also the e-brake shoes can shift over one way or the other when pulling the rotor off, you just need to bump it over the correct way with your hand if that's the case.

(Obviously you don't have the e-brake handle pulled....)

07-31-2020, 03:02 PM	#1
billmidd08 Scooby Newbie Member#: 39599 Join Date: Jul 2003 Location: cali Vehicle: 08 STI Hatch WRB	New rear rotors won't install - caught on rear drum friction material So I started a project of refreshing my rear brakes by flushing fluid, replacing my **ty wheelstuds with ARP studs along with installing new centric high carbon rear rotors and new Project Mu rear pads all at the same time. Flush is done, new wheelstuds are installed, but am encountering some issues on the rear rotors. Trying to get the new rotor mounted on the new studs and found it will not clear the ebrake drum. In fact, it won't fit my old worn rotor back on either at the moment, tried it just for *s and giggles and to make sure my new rotors are the right size (they are). I turned the star adjuster at the bottom of the drum to full loose but I'm not sure it's actually shrinking the circumference to get more clearance, the edge of the drum friction material is still barely catching the inner rotor lip on full loose. I've turned the star adjuster up and down a good chunk of its range a few times... and nothing visually looks out of place to me. Does anyone have a rear drum tips/tricks? ...or a manual if I need to actually disassemble the ebrake drums. Registered users of the site do not see these ads.

08-01-2020, 02:38 PM	#3
billmidd08 Scooby Newbie Member#: 39599 Join Date: Jul 2003 Location: cali Vehicle: 08 STI Hatch WRB	Nope, definitely not able to compress them by hand with the adjuster loosened. Will see if I can unfreeze it. EDIT UPDATE: after brake cleaner and grease was able to brake everthing free and get some wiggle room to successfully get the rotor mounted. Last edited by billmidd08; 08-01-2020 at 04:08 PM. Reason: update

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08-01-2020, 03:32 PM	#4
2slofouru Scooby Guru Member#: 90539 Join Date: Jul 2005 Chapter/Region: South East Location: SWLA Vehicle: My BOV goes COVFEFE!	You may have purchased normal wrx rotors that have a smaller ID for the e-brake shoes. That would prevent them from sliding over the larger STi e-brake shoes. Also the e-brake shoes can shift over one way or the other when pulling the rotor off, you just need to bump it over the correct way with your hand if that's the case. (Obviously you don't have the e-brake handle pulled....)