So my last 914 had a non-working E-Brake. Everything was hooked up, it just didn't work and because the po had informed me of the situation I just never questioned it. When the body finally rusted away I found a roller to do an engine swap with. One of the things that excited me about this roller was that it had been converted to a 911 5-lug suspension in front and the words "New Eric Shea rear calipers & bushings with 5-lug hubs" jumped out at me.
How cool - Brakes that would actually work like they were supposed to, which to me meant an E-Brake, too. No more hopping out of the car and quickly throwing a rock behind the tire !!!
Well, to my surprise I still dont have a working E=Brake system. I adjusted the cables, then moved on to adjust the vent clearance and found this on the inside
adjuster.Click to view attachment
On closer inspection, There appears to be nothing to adjust with behind the plug, and when I rotate the lever nothing inside appears to move and the piston does not extend to push against the disc
Click to view attachment
The outside caliper adjustement worked just fine,
So - "Is this a thing" to dismantle the e-brake on the inside of the caliper?
Full Version: Is this a Thing?
Nope. The adjust just slides in or out. Get a new one, pop it in and bobs yer uncle.
QUOTE(McMark @ May 23 2015, 01:13 AM) 
Nope. The adjust just slides in or out. Get a new one, pop it in and bobs yer uncle.
Thanks Mark. I will look for the adjusters here locally then.
Steve
Another question.
How far should the piston travel when the caliper e-brake arm is fully rotated from stop to stop? And/or Would the missing adjusters cause the piston to not move?
Thanks,
Steve
How far should the piston travel when the caliper e-brake arm is fully rotated from stop to stop? And/or Would the missing adjusters cause the piston to not move?
Thanks,
Steve
QUOTE(McMark @ May 23 2015, 01:13 AM)
Nope. The adjust just slides in or out. Get a new one, pop it in and bobs yer uncle.
Mark,
Another question.
How far should the piston travel when the caliper e-brake arm is fully rotated from stop to stop? And/or Would the missing adjusters cause the piston to not move?
Thanks,
Steve
Roughly 1/8"
The missing gear has nothing to do with that amount of travel. The missing gear will allow you to adjust venting clearance to .004". That measurement is crucial especially on the inside adjuster as it is the piston that does all the work. When it is adjusted properly, that piston shoves the pad into the rotor which shoves the rotor into the outer pad which... engages the handbrake.
This is why adjusting your venting clearance is so critical on a 914. This is also why I say 80% of the 914's on the road today do not have functioning rear brake calipers. It's Spring time, time to adjust your rear venting clearance.
The missing gear has nothing to do with that amount of travel. The missing gear will allow you to adjust venting clearance to .004". That measurement is crucial especially on the inside adjuster as it is the piston that does all the work. When it is adjusted properly, that piston shoves the pad into the rotor which shoves the rotor into the outer pad which... engages the handbrake.
This is why adjusting your venting clearance is so critical on a 914. This is also why I say 80% of the 914's on the road today do not have functioning rear brake calipers. It's Spring time, time to adjust your rear venting clearance.
QUOTE(Eric_Shea @ May 25 2015, 10:42 AM)
Roughly 1/8"
The missing gear has nothing to do with that amount of travel. The missing gear will allow you to adjust venting clearance to .004". That measurement is crucial especially on the inside adjuster as it is the piston that does all the work. When it is adjusted properly, that piston shoves the pad into the router which shoves the rotor into the outer pad.
This is why adjusting your venting clearance is so critical on a 914. This is also why I say 80% of the 914's on the road today do not have functioning rear brake calipers. It's Spring time, time to adjust your rear venting clearance.
Thanks for the reply.
I have two rear calipers, per above picture, that came on a roller I purchased and they were advertised as new (I assume rebuilt and never used by the looks of them) although they have sat for probably 3-6 years.
The pistons do move when energized with compressed air (against a piece of wood between them.
But:
- I don't seem to get a notable inner piston travel from either one when the E-brake arm is rotated - what could cause that?
Other problems with them:
- They are missing the inside adjusters (which I understand can be replaced easily).
- The outside adjuster on one caliper doesn't appear to be causing the piston
to move.
I am quite sure I am going to ship them to you for inspection and/or rework but want to make sure I am not doing so unnecessarily So would appreciate your thoughts on what might cause the problems I am seeing.
Steve
<<- I don't seem to get a notable inner piston travel from either one when the E-brake arm is rotated - what could cause that?>>
The inner adjuster has been adjusted too far inward and the adjuster itself has been pulled up into the piston tight. It is now off the small pushrod which rests against the handbrake arm. When you get the gears, turn them clockwise to push the piston out. Turn them until you can "just" feel the piston move in the outward direction. Now your handbrake arm will work as the connection between the small pushrod and the handbrake arm are solid.
<<Other problems with them:
- They are missing the inside adjusters (which I understand can be replaced easily).>>
They are missing the inner adjuster "gears" which slide down that shaft under the cap. As easy as stop, drop and roll. The inner adjuster itself is in the caliper and screwed in tight to the piston (too tight from what you're saying above)
<<- The outside adjuster on one caliper doesn't appear to be causing the piston to move.>>
More than likely due to sitting. The internal adjustment mechanism is held in the piston with a C-Clip. If the adjuster itself is bound up in the mechanism, the mechanism will simply spin in the piston shell. The best way to solve this problem is with a 4mm hex on a high speed air wrench. An air wrench reaches velocity almost instantly vs. a drill or a ratchet wrench.
1. Loosen the 13mm stop nut.
2. Remove the pads.
3. In short bursts, zip the 4mm hex in a counter-clockwise direction.
That should free up the adjuster inside the mechanism. Once it's moving, use your thumb to apply pressure to the piston top as you turn the 4mm hex in a clockwise direction to pull the piston back in.
"Remember" - The INNER adjusters have the same right handed thread pitch BUT... because they are driven by that gear, they will adjust in reverse.
(and yes, even used inner adjuster gears are expensive...)
You may need to try the air wrench trick with the inner adjuster as well. Remember "Clockwise" for those and "Counter-Clockwise" for the outer
The inner adjuster has been adjusted too far inward and the adjuster itself has been pulled up into the piston tight. It is now off the small pushrod which rests against the handbrake arm. When you get the gears, turn them clockwise to push the piston out. Turn them until you can "just" feel the piston move in the outward direction. Now your handbrake arm will work as the connection between the small pushrod and the handbrake arm are solid.
<<Other problems with them:
- They are missing the inside adjusters (which I understand can be replaced easily).>>
They are missing the inner adjuster "gears" which slide down that shaft under the cap. As easy as stop, drop and roll. The inner adjuster itself is in the caliper and screwed in tight to the piston (too tight from what you're saying above)
<<- The outside adjuster on one caliper doesn't appear to be causing the piston to move.>>
More than likely due to sitting. The internal adjustment mechanism is held in the piston with a C-Clip. If the adjuster itself is bound up in the mechanism, the mechanism will simply spin in the piston shell. The best way to solve this problem is with a 4mm hex on a high speed air wrench. An air wrench reaches velocity almost instantly vs. a drill or a ratchet wrench.
1. Loosen the 13mm stop nut.
2. Remove the pads.
3. In short bursts, zip the 4mm hex in a counter-clockwise direction.
That should free up the adjuster inside the mechanism. Once it's moving, use your thumb to apply pressure to the piston top as you turn the 4mm hex in a clockwise direction to pull the piston back in.
"Remember" - The INNER adjusters have the same right handed thread pitch BUT... because they are driven by that gear, they will adjust in reverse.
(and yes, even used inner adjuster gears are expensive...)
You may need to try the air wrench trick with the inner adjuster as well. Remember "Clockwise" for those and "Counter-Clockwise" for the outer
QUOTE(Eric_Shea @ May 25 2015, 04:13 PM)
<<- I don't seem to get a notable inner piston travel from either one when the E-brake arm is rotated - what could cause that?>>
The inner adjuster has been adjusted too far inward and the adjuster itself has been pulled up into the piston tight. It is now off the small pushrod which rests against the handbrake arm. When you get the gears, turn them clockwise to push the piston out. Turn them until you can "just" feel the piston move in the outward direction. Now your handbrake arm will work as the connection between the small pushrod and the handbrake arm are solid.
<<Other problems with them:
- They are missing the inside adjusters (which I understand can be replaced easily).>>
They are missing the inner adjuster "gears" which slide down that shaft under the cap. As easy as stop, drop and roll. The inner adjuster itself is in the caliper and screwed in tight to the piston (too tight from what you're saying above)
<<- The outside adjuster on one caliper doesn't appear to be causing the piston to move.>>
More than likely due to sitting. The internal adjustment mechanism is held in the piston with a C-Clip. If the adjuster itself is bound up in the mechanism, the mechanism will simply spin in the piston shell. The best way to solve this problem is with a 4mm hex on a high speed air wrench. An air wrench reaches velocity almost instantly vs. a drill or a ratchet wrench.
1. Loosen the 13mm stop nut.
2. Remove the pads.
3. In short bursts, zip the 4mm hex in a counter-clockwise direction.
That should free up the adjuster inside the mechanism. Once it's moving, use your thumb to apply pressure to the piston top as you turn the 4mm hex in a clockwise direction to pull the piston back in.
"Remember" - The INNER adjusters have the same right handed thread pitch BUT... because they are driven by that gear, they will adjust in reverse.
(and yes, even used inner adjuster gears are expensive...)
You may need to try the air wrench trick with the inner adjuster as well. Remember "Clockwise" for those and "Counter-Clockwise" for the outer
Thanks again. Glad to have a few things to try this week.
Steve
QUOTE(pneuhyde @ May 25 2015, 11:01 PM)
QUOTE(Eric_Shea @ May 25 2015, 04:13 PM)
<<- I don't seem to get a notable inner piston travel from either one when the E-brake arm is rotated - what could cause that?>>
The inner adjuster has been adjusted too far inward and the adjuster itself has been pulled up into the piston tight. It is now off the small pushrod which rests against the handbrake arm. When you get the gears, turn them clockwise to push the piston out. Turn them until you can "just" feel the piston move in the outward direction. Now your handbrake arm will work as the connection between the small pushrod and the handbrake arm are solid.
<<Other problems with them:
- They are missing the inside adjusters (which I understand can be replaced easily).>>
They are missing the inner adjuster "gears" which slide down that shaft under the cap. As easy as stop, drop and roll. The inner adjuster itself is in the caliper and screwed in tight to the piston (too tight from what you're saying above)
<<- The outside adjuster on one caliper doesn't appear to be causing the piston to move.>>
More than likely due to sitting. The internal adjustment mechanism is held in the piston with a C-Clip. If the adjuster itself is bound up in the mechanism, the mechanism will simply spin in the piston shell. The best way to solve this problem is with a 4mm hex on a high speed air wrench. An air wrench reaches velocity almost instantly vs. a drill or a ratchet wrench.
1. Loosen the 13mm stop nut.
2. Remove the pads.
3. In short bursts, zip the 4mm hex in a counter-clockwise direction.
That should free up the adjuster inside the mechanism. Once it's moving, use your thumb to apply pressure to the piston top as you turn the 4mm hex in a clockwise direction to pull the piston back in.
"Remember" - The INNER adjusters have the same right handed thread pitch BUT... because they are driven by that gear, they will adjust in reverse.
(and yes, even used inner adjuster gears are expensive...)
You may need to try the air wrench trick with the inner adjuster as well. Remember "Clockwise" for those and "Counter-Clockwise" for the outer
Thanks again. Glad to have a few things to try this week.
Steve
Update to this thread.
I bought 2 inner adjuster gears from High performance House out here.
Installed them and used a drill to spin them and the outer adjusters in and out
a few times and added in some air pressure to move the pistons also.
I now have both inners and one outer adjuster working properly, and my E=brake levers work their related piston, Too. Yay!!
Now I just have to figure out where to beg, borrow, or steal (no-maybe buy) an air wrench to try on the last adjuster. Really stoked to think I might get my brakes back together without having to send them off and wait...
Thanks Mark and Eric for the help with this.
Steve
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