2017 Chevy Volt rear calipers

mhamilton85

Newbie
Joined
Aug 27, 2019
Messages
20
Points
1
Make
Chevrolet
Model
Volt
Year
2017
Miles
27000
Engine
Voltec
Quick question: the rear calipers on the Chevy Volt (2nd generation--2016 and up) have electric parking brake actuators on each rear caliper. If I want do do a simple pad R&R, do I need to do anything special here? It appears the motors on each caliper simply actuate the integral parking brake mechanism the same way a cable pull mechanism would do. Assume I would just wind in the pistons as with any other integral parking brake caliper. I want to be sure before I start taking things apart and find out a need a Tech 2 to recalibrate them.

Here's a photo I found from the Rockauto catalog:
18B5538-ang__ra_p.jpg

Thanks,
-Michael
 

grcauto

Hero Member
Joined
May 29, 2014
Messages
703
Points
28
A scan tool will retract it quick but you can turn it in by hand.
 

Mobile Dan

wrench
Joined
Mar 1, 2002
Messages
3,668
Points
48
Location
Kentucky
Some vehicles have a way to retract p-brake in a "Service Mode". (a computer does the work for you) I have retracted some by (carefully) using a 12v source like a jump box. Removing the motor can be difficult due to rust/plastic/threadlocker. Some motors have a "manual" option if you remove a cap or plug.
 

mhamilton85

Newbie
Joined
Aug 27, 2019
Messages
20
Points
1
Hey guys, sorry for the confusion. Not looking to retract the parking brake. It's working fine. I just want to make sure I can wind in the pistons to install new pads.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,747
Points
48
Well, the confusion just started (or got worse) for me. You need to "wind" the pistons to retract them so you can install the (thicker) new pads. Those are all the same operation. Winding pistons, retracting pistons, retracting parking brake all mean the same thing in context of changing the brake pads, I think.
 

mhamilton85

Newbie
Joined
Aug 27, 2019
Messages
20
Points
1
When I say "retract the parking brake" I meant release the brake. Like pull the parking brake release.

If this was a standard GM rear caliper with integral parking brake, I'd just release the PB handle, remove the pads, and turn the caliper piston back in. I think I can to do the same thing on these, just have an electric motor in place of a lever and cable.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
6,747
Points
48
OK, I got it now. You are wondering if something will get damaged or the parking brake will be inop if you turn the pistons manually instead of driving the motor. That was my original interpretation of this thread, and I think it is still a valid concern. The replies above are not completely clear to me, about it being OK to do it manually, so be wary. Without knowing the design of that motor/piston/caliper assembly I can only guess, but it seems unlikely to me that screwing the piston in manually, with no power applied to the motor, would work.
 

mhamilton85

Newbie
Joined
Aug 27, 2019
Messages
20
Points
1
Finally found out from another Volt owner that the rear calipers are serviced the same as any ordinary rear calipers. Just wanted to post this to close out this thread.

The parking brake actuator on these calipers is not as complicated as thought. It's basically a glorified power door lock motor. 2 wires, no position sensor. It literally just replaces the lever and cable with a motor that moves the same part in the caliper fwd and back 1". So once the PB is disengaged, it's safe to rewind the pistons by hand. The motor doesn't even have the ability to retract the piston via OE scan tools.
 

NickD

wrench
Joined
Aug 28, 2007
Messages
4,987
Points
48
Love my 88 Supra Turbo and son's 2010 Dodge Nitro, for rear disk brakes, the caliper is self adjusting just like the fronts, parking brake are drums inside the same rotor. Parking brakes never wear out, if just used for parking. I was able to rebuild the rear caliper on my Supra for $2.41 and make it like new again.

Combination caliper parking and service brakes are way overpriced and not very reliable particularly in salt based sections of the country. a ratcheting mechanism is used to adjust the brakes, amazing, they don't even explain this in many owners manual, you have to work the parking brake, parked to take up a low brake pedal. and since the lever is exposed, rusts, or the ratcheting mechanism brakes, $$$ for new caliper.

Do need pad brackets, before these had to grind the ridge off the rotor to remove the calipers, generally just two bolts to lift off the caliper assembly. And no standard for screwing in the piston, everyone requires a different tool, see your Volt is really special. And it just screws in, does have a rubber boot on it, sure helps to remove that boot when new and fill that gap between the caliper housing and that piston with silicone. If you don't that piston will be seized against the housing, factories don't do this.

Screwing it in doesn't have anything to do with the ratcheting mechanism that screws it out. Here the piston is locked to the outer pad, make sure its lined up properly. If the pistons turns with the ratchet, won't take up the play.

Met some mechanical engineers that smoke crack, an electric motor to apply the parking brakes. With the brakes applied, can't even push the darn thing off the road with a dead battery. Also a very high torque motor, that if it doesn't have a limit switch, extremely difficult, motor stalls current can go up to a thousand amps, and burn it out, really stupid engineering.

Ha, test drove a Volt in town, really quiet, but if on the interstate, would prefer a long extension cord.

Every energy conversion is an energy loss, even as much as more than 50%, burn coal to run a turbine, convert mechanical to electrical, loss in long transmission lines, another loss in charging a battery, than another loss from electrical to mechanical. Works good in California as the coal burning plants are in Nevada, uses more carbon emissions as far as the earth is concerned, but lightens these emissions in congested areas.

We have plenty of ethanol plants in Northern Wisconsin, that slightly lightens the emissions in Milwaukee and Madison, takes just a much fossil fuel to make an equivalent amount of ethanol, global wise, worse, but moves some of the stink out of Milwaukee and Madison, up to our once fresh air.

Really have a country ran by idiots or crooks, take your choice.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,000
Points
63
Location
St-Hyacinthe, Quebec, Canada
I dont know, but sometimes, going on multiple sites can cause confusion.


The motor doesn't even have the ability to retract the piston via OE scan tools.

This statement is totally false. Any good scanner with proper bidirectional has the option to retract caliper for service, and here is the proof. I am sorry, and I am not aiming to blast another site such a a volt site, but again, false.

Screenshot (13).png
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,000
Points
63
Location
St-Hyacinthe, Quebec, Canada
As for other statements, yes, you can retract them your self, and as told in our night courses way back when, when these electric parking brakes came out, if you dont have a scanner, best way is to manually do so if possible, and disconnect caliper motor servo to make sure they dont apply whilie you have your fingers in there if you dont have the ability to put in service mode.

Which I think was the essence of this question at first premise.

And YES, there is a calibration. It is in the option menu. On the tech 2 it will be in the EBCM menu, on my autel 908pro it is in the hot function menu.

I like the autel for that, it simplifies. But getting a clone TIS2web may work for you. If this is your personal car, I would definatly look into buying one of these. https://www.amazon.ca/VXDIAG-Multiple-TIS2WEB-Diagnostic-Programming/dp/B01NACTAY8

Screenshot (14).png
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,000
Points
63
Location
St-Hyacinthe, Quebec, Canada
So that being said, yup, you can do that all by yourself, with little to no risk, but some ppl have not taken measures and have lost bits of hands cause they forgot to put car in service mode, and while car on hoist, busy bee swapping pads, caliper decides to engage, when that glorified door lock thing you talked about is enough to make you howl if your not quick enough to get digits out of the way. This is all a safety precaution.

I work in this trade day in and day out. I even have techs at my work who come to me to disengage the parking brake cuz they cant read english and hate the scanner. So I kinda like tooting my horn here, it is fun to have this database at my finger tips and not rely on false data from some redneck down in texas. Mind you, I have met a few real smart rednecks, so I cant just blatantly say that without some form of repercussion. Just trying to be humorous. Like the red green show. I love this guy and modeled myself on this canadian form of redneck.

But with some of these newer cars, just plz dont listen to every one. If someone said the volt does not have parking brake bidirectional applicability, I would invite him to listen to this.
 

mhamilton85

Newbie
Joined
Aug 27, 2019
Messages
20
Points
1
Nick, I appreciate your help and everyone's help on this forum. I wasn't trying to indicate I got a wrong answer here. I think that we're arguing over semantics at this point.

I have no doubt that there is a service mode for the rear EPB. On my Jaguar, the EPB Service Mode does exactly the same thing as you sitting in the car and pulling the EPB release. Can this Chevy actually retract the rear caliper piston all the way to zero? Yeah, you're right, I suppose it is possible with this design if the screw shaft goes from the EPB motor right through the piston.

I never doubted the torque ability of the EPB motors. I just said it's a simple 2 wire setup, meaning it does not have a position sensor so I think its functionally is limited to "fwd" and "rev" depending on the DC polarity applied, like a power door lock motor. I'm sure I would do well to disconnect the 12v battery when servicing the rear brakes to avoid any potential risk to limbs. Or I can unbolt the motor from the caliper and turn them back by hand, thereby not risking damage to myself or the motor.

I do have a LAUNCH X431 CRP429C, which has some limited bi-dir functions like parking brakes, battery resets, etc. When I get around to doing the job I will have to see if this has any functionality to help with this job.
 
Last edited:

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,000
Points
63
Location
St-Hyacinthe, Quebec, Canada
LAUNCH X431 CRP429C
Well, just perused the manual, it is NOT optional, so yeah it will reset parking brake if the car allows protocal.

In a firther sense, I think your response was a bit due to me being to cozy with terminology.

Darn, further hate frenchkeyboards, haveto constantly swich.

Anyway, je pense que je me suis mal exprimé, alors je vous doit des excuses.

I felt in your last response you may have felt I was condescending. I assure you, it was not. It was for informational puroses only, the vids I link to are a kink of mine some have to endure, part of who I am. àà

When adult class comes back on in monreal, I will update the ev thread, no use now, not the time to check that out.

I upmostly thank you for your promp replies, they help focus techs like mobile dan, BP, Kev2 and someother soon to be retired. I am only 45, so still a way to go, if I make it.

;);):beer::beer::beer:
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,000
Points
63
Location
St-Hyacinthe, Quebec, Canada
In this time of need, clarity of thought and also clarity of charity. My first love was here. I love giving to others what is so readily available to me.

I know this may sound piss ant, but this site got me out of a homelless situ in Toronto. And ever since, I have not asked anything ecept for a hat or two.

Oh and some stickers for my tool box setup. Which btw I never showed jordan that. anyway.

My sister is going down tubes, I am to emotional to deal with that and if I pissed you off for some reason, beleive me, it was not intentional, and I have no patience to filter my comments, I dont need a AR15 to make a point.

 
Top