Hey guys. Doing brakes and Rotors on my Mk4 golf tdi (2005). On my rear drivers side caliper (left side), I can’t get the piston to retract for the life of me. I’ve got the special tool for it (one of those kits with all the different adapters so yes I’ve got a plate on that keys into the piston properly). I rotate the piston clockwise and it’ll spin for days but it just won’t actually retract. Do I need a new Caliper? This is my first time doing this so it’s quite possible I’m doing something simple wrong. Any ideas?
Rear caliper Piston won’t retract
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red16vdub
Veteran Member
When using the tool to retract the piston, yoI have to apply some force as you’re turning clockwise. If you’re doing that a its not retracting, itdd so possibly your piston cam out to far, and it’s not seated properly.
P2B
Top Post Dawg
This is the tool you need to apply pressure while turning:
Metalnerd Rear Brake Tool (VW)
Metalnerd Rear Brake Tool is required for rear brake jobs on VWs and some Audis from 1989 through Mk7 that use a manual parking brake handle. These calipers need to have the piston rotate...
www.idparts.com
this what I have yea, but a full kit with left hand right hand and different adapters with different sizesThis is the tool you need to apply pressure while turning:
Metalnerd Rear Brake Tool (VW)
Metalnerd Rear Brake Tool is required for rear brake jobs on VWs and some Audis from 1989 through Mk7 that use a manual parking brake handle. These calipers need to have the piston rotate...www.idparts.com
how might I go about getting it reseating? Should I just take the whole caliper off the car and take it apart/put it back together?
I’m pretty confident Im doing the motion right. But then again it’s possible I’m doing something off.
Try spraying penetrating oil around the dust boot. If that does not work you may need to replace the caliper. The local part store remans are not very reliable in my experience. idparts has new calipers that I have had good luck with both rears.
Lug_Nut
TDIClub Enthusiast, Pre-Forum Veteran Member
- Joined
- Jun 20, 1998
- Location
- Sterling, Massachusetts. USA
- TDI
- idi: 1988 Bolens DGT1700H, the other oil burner: 1967 Saab Sonett II two stroke
Two considerations
The retraction tool thread pitch might not match the thread pitch in the caliper. It might turn 'faster' than it 'pushes in'. My major-chain parts store kit doesn't match and I need to reset the press force on the tool's threaded sleeve after every turn of two of the piston to permit actually pushing the piston in as it turns.
Or a prior brake job didn't turn, but just pressed, and damaged the helical thread on the piston and/or caliper. It might never thread back.
The retraction tool thread pitch might not match the thread pitch in the caliper. It might turn 'faster' than it 'pushes in'. My major-chain parts store kit doesn't match and I need to reset the press force on the tool's threaded sleeve after every turn of two of the piston to permit actually pushing the piston in as it turns.
Or a prior brake job didn't turn, but just pressed, and damaged the helical thread on the piston and/or caliper. It might never thread back.
Solution Found!! Thanks for all the replies. I had tried pumping the brake to get it moving and then getting after it with the tool post brake pumping last night. that hadn’t worked. I ended up opening the brake fluid container (idk what you actually call it, under the hood) and then pumped the brake 2-3 times. The piston came out a bit as-well as a small amount of brake fluid pushed up in the container itself and spilled out. (I cleaned that up) After getting the tool back on with the container still open, the piston went right in. Requiring a quarter of the force I was previously using. I was planning on bleeding the brakes out after finishing all the pads/rotors anyway so I really didn’t mind trying this. I imagine just releasing some pressure from the system is what did it, but who knows. Maybe the fluid was slightly overfilled, (haven’t had the car very long so idk) Hope this helps someone who runs into something similar in the future!
I had also read online that some people will open up the bleeder valve and then retract the piston. I imagine this functionally did the same thing.
Prairieview
Veteran Member
- Joined
- Jul 9, 2017
- Location
- Too close to Sturgis 'ithole
- TDI
- Two 2000 Beetles, 2002 Jetta, 2002 gas avh Jetta, fleet of older 1.6 turbo and non's
I never regret taking the time to thoroughly flush ALL the old brake fluid out. I rarely need to replace calipers.