Sticky Rear brake every think new - ideas?

[Nemi.]

Hello

I have an issue with one site of my rear brake having the symptom of sticking.
Roter getting very hot compared to the other side. Even hotter than the front brakes.
The sticking is not to the point where you can’t turn the wheel when jacked up. It run by itself a couple of rounds, but you can hear it being dragged a little.
Caliper are with electronic parking brake function

When first notice I chance the Roter and brake pads. The caliper looked fine and in "brake pads replacement state" the caliper returned without any issue.
Slider and the slate have been cleaned and lubricated with grease.

After a couple of drive, I notice they still got hot.
I took another look at the caliper and descended that I would change it, because it look like the gasket were damage.
I have change caliper before on other VW, so pretty standard job. Only different on the MK7 is the connection for the break hose, sins they use single screw instead of turning the hole break hose.
An to clear out no clamp were used on the break hose.


At first I thought the caliper change did the trick because it looked like they didn’t get hot anymore, but now I have change to summer tires and yet again I notice they get hot.
again I have pushed the caliper back just to be sure it were not an calibration issue ore somethink like that and the slide, slate, brake pads and roter all cleaned and lubricated.
After this I went for test drive and looking at my mile consument it looked like something had change for the better, but when I got home I check the hotness of the roter and it were still very hot compared to the other side.



I feel like I am missing something and hope for some advice

 

[gixxerfool]

I would recommend changing the rubber hose to the caliper as well. They can collapse internally and not allow the fluid to return when you release the brake pedal.

 

[Nemi.]

I would recommend changing the rubber hose to the caliper as well. They can collapse internally and not allow the fluid to return when you release the brake pedal.

Thx for the advice
is there a way to test to see if that is the problem?

 

[gixxerfool]

Thx for the advice
is there a way to test to see if that is the problem?

Not really. If it were a front and completely locked, you could, but this seems to be more a dragging issue.

 

[Nemi.]

Hose have been replace with new one and the problem were not resolve

 

[golfdave]

Its the internal rubber seal between the piston & the caliper body....get the repair kit..it should also contain the outer visible rubber boot or skirt which you see.

The internal rubber seal actually "pulls" the piston back away from the pads just enough to allow the disc to rotate freely....

I would also only use the supplied grease in the kit for the seals...but use the Loctite LB8009 heavy duty on the metal to metal of the pad backs & ears to the caliper slide contact points.

Also only use the TRW specific grease for their callipers called PFG-110 & this only for the slide pins which are under the accordion rubber boots....this could be another reason why the calipers are repeatedly working & then sticking...wrong grease has been used...

 

[Nemi.]

Its the internal rubber seal between the piston & the caliper body....get the repair kit..it should also contain the outer visible rubber boot or skirt which you see.

The internal rubber seal actually "pulls" the piston back away from the pads just enough to allow the disc to rotate freely....

I would also only use the supplied grease in the kit for the seals...but use the Loctite LB8009 heavy duty on the metal to metal of the pad backs & ears to the caliper slide contact points.

Also only use the TRW specific grease for their callipers called PFG-110 & this only for the slide pins which are under the accordion rubber boots....this could be another reason why the calipers are repeatedly working & then sticking...wrong grease has been used...

Don’t believe the issue are the seal of the caliper, as mention the caliper is new and it can be push back only using the hand

 

[golfdave]

Don’t believe the issue are the seal of the caliper, as mention the caliper is new and it can be push back only using the hand

Ok then what about the slide pins that connect the caliper piston housing to the caliper bracket, and are covered with the rubber boots? I bet they need cleaning & properly greasing with the TRW grease..

 

[Nemi.]

Ok then what about the slide pins that connect the caliper piston housing to the caliper bracket, and are covered with the rubber boots? I bet they need cleaning & properly greasing with the TRW grease..

they have been cleaned and greased, with the same as the other 3 caliper. No problem there, so guess the grease is fine

 

[golfdave]

they have been cleaned and greased, with the same as the other 3 caliper. No problem there, so guess the grease is fine

The only thing I can thing off is that if as you say everything is ok then go back & re-do the VCDS parking brake service position activate & then deactivate....just to make certain the piston/pad clearance is set correctly..

 

[Nemi.]

my thought as well, so I did and then measure the roter to see if it were out of alignment, but nothing there.
To be sure and rule out the roter and the brake pads I swapped the rear once to see if the problem followed to the other side. If no change there, then I try with the slidepinds, but the once that run most smoothed are the once on the brake getting hot.

 

[Bagarn]

Hello,

I have the exact same problem on my Golf 1.6 TDI MY13. The problem first appeared on one side, replaced that caliper and it was fine a while. Then the other side got hot, so replaced that caliper too. Then again both sides got hot so replaced the brake lines but that still has not solved the issue. Have now ordered new pads and rotors if they some how causes this, the current pads are pretty worn.
Did you find out what the issue was?