Clean / replace caliper slide pins

[Declan O'Shaughnessy]

Hi All,

 

Just wanted to ask what I'm hoping is a quick (and straightforward question): I have a problem with a consistently sticking / seizing brake caliper on the rear driver's side of my Superb. I had the caliper itself replaced back in February, but for the last week or so it is sticking quite badly again. Looking at it just now, it looks like the garage replaced the caliper unit itself but left the orginal bracket (with the slide pins) in-situ. So I'm thinking I need to disassemble the unit and grease the pins, or replace them altogether. I can see repair kits online, and I've got a good idea what to do from watching videos on Youtube. My only question is this: do I need to have a caliper wind-back tool before I start? From looking at the videos, most seem to suggest that there isn't a need for a wind-back tool at all. But one video did show the mechanic using a wind-back tool. So I don't want to take the caliper off and then discover I can't get the bloody thing back on again! Other than that, I'm hoping it is a straightforward job that I can do myself without resorting to a garage again.

 

All help greatfully received.

 

Many thanks,

 

Declan.

[foru2justnv]

You will need a windback tool. https://www.ebay.co.uk/itm/114581339679. Don't buy the other cheaper types they dont have the strength and slip. This has a spanner fitting on the piston the others dont. 

 

My way not necessarily the right way is, release cable from caliper mechanism and then grease up the sliders good, remember position of caliper piston, wind the caliper back in fully, then without pads or caliper bolted on, attach cable and pull handbrake up a few times to get piston moving again past the point of where it was when you started, then apply grease to piston, you can get some spray grease further on by lifting rubber seal, then wind back again and repeat a few times. 

 

[Snapper1725]

Hi

I had it when my pads were seized in the carrier ( dealership serviced 😤) 

I would have expected the garage would have cleaned lubricated the slides.

If not, if you take the caliper off ( it should go back on if not replacing pads ) and remove pads, clean the grooves (Carrier) pads fit in ( if it has metal slide covers remove them) and give everything a good clean. make sure the pads are free moving afterwards.
Also lubricate caliper sliding pins 

 

The carrier is better cleaned off the car but is a bit of a pig to get off and requires a M14 spline drive 

 

 

[Declan O'Shaughnessy]

@foru2justnv & @Snapper1725 Thanks guys, much appreciated. Sounds like it may be sensible to buy a windback tool, just to be on the safe side. Or else just take it to a garage and let them worry about it!

[foru2justnv]

Just dont buy this one. If your piston is stiff this will slip

 

[Declan O'Shaughnessy]

@foru2justnv Duly noted. To be honest, given the cost of the windback tool, the pin repair kit and the time it will no doubt take me (every time I do something mechanical on the car I swear never again!), I'm leaning towards just taking it to a local garage and letting them at it. I'll probably buy the tools later on, but really I need it looked at sooner than the time it would take to get the windback tool from Amazon and the repair kit from eastern Europe etc. I am still in two minds, but I think I'll speak to a garage today and see what it would cost to get them to do it.

[Snapper1725]

If you do buy one make sure you remove brake fluid reservoir top before winding the piston back.

Also check that you are not twisting the piston boot also, you may have to wind piston back slightly in then remove tool to and turn boot back round if it’s sticking to the piston 

Halfords do the Laser one which I bought

Edited 13 July, 2021 by Snapper1725

[Declan O'Shaughnessy]

@Snapper1725 Thanks. Getting more complicated by the minute! And in general I'm not a fan of fecking around with brakes with my level of knowledge.

[foru2justnv]

No its very simple. 

Watch this it will help you

https://youtu.be/DNF8QNJs6cU

[chimaera]

The main thing with the rear brakes is to make sure the windback tool rotates the piston as it goes in, and doesn't just push straight back. For the slide pins, probably all that's needed is give the pins and the socket they slide in a rub down with some 600 grit emery paper and put some grease on them.

[Declan O'Shaughnessy]

@foru2justnv Famous last words! Yeah, that's one of the videos I'd looked at, but I know from experience that Autodoc's videos make things look far simpler than they are. But anyways, you've talked me into it. I ordered the windback tool and grease and I'll give it a bash once they arrive. When it all goes pear-shaped, I'm holding you firmly to account! Thanks for all the help.

 

@chimaera Thanks for that. I also ordered some 600 grit paper as recommended, so hopefully it will all go to plan and the car will stop fecking me about for a while.

[foru2justnv]

Lol. Thats fine no worries will be on hand to help. Give me a shout

[Declan O'Shaughnessy]

Right, well, I bit the bullet and tackled this job this morning. Amazingly, it went very smoothly and I didn't really run into any problems at all (which is pretty much a first for me!). So many thanks to @foru2justnv for talking me into it and for the advice offered by @chimaera and @Snapper1725. I could have got away with not using the wind back tool in the end, but decided it was just as well to try it out and get a feel for it. The caliper slide pins looked in good condition to me, but I cleaned them up and re-greased them. I scrubbed the carrier a bit with a wire brush and the caliper bolt seemed to push back nice and smoothly. But...

 

After all that, the problem is still there! I took the car for a short drive (20 minutes) and the brake disc / housing was very hot by the time I got back. So I'm at a loss as to what to do next. I'm hoping someone on here can point me in the right direction, so here's the full background to the problem:

 

If I drive the car for any length of time at all (say 15 minutes or more), I start to hear a squeal at low speeds. The squeal doesn't seem to be there at higher speeds most of the time, but sometimes you can hear it at higher speeds. If I stop the car and check the rear wheel (driver's side) disc and housing etc. it is very hot (red hot if I drive for long enough). After this morning's test, the disc temperatures on the other 3 discs was reading circa 40c. On the problematic disc, it was circa 140c. I have found that if I pump the brakes (with the engine off) it seems to cure the problem, at least for a while and the wheel / disc cools down again. But sometimes this doesn't work, so it might just be psychosomatic! So this is why I assumed it was a sticking caliper, but it looks like it isn't.

 

Is there anything else I can check myself? The only thing I can think of is the disc shield (or whatever it is called) that sits on the hub. This has gotten pranged many times over the years with me taking the wheel on and off etc. so could this be the problem? From what I've read, when these cause problems you get a horrible screeching sound that is constant, which isn't what I'm experiencing. Plus I haven't read of the friction they cause heating the wheel / disc to the extent that I'm experiencing. From what I can make out, the shield doesn't do a whole lot and I've read posts on here where people just cut them off. If I was going to remove it, I think I'd rather remove it properly, which I think means taking the whole hub off, so probably a job for a garage. But if this isn't going to be the problem, then I'd rather not waste money.

 

So is there anything else I'm missing? I did replace the rear bump stops, springs and shocks myself a couple of months ago, but I don't think this could be causing the problem could it? I'm happy to admit I might not have done a perfect job, but the problem was there before I did the work (to the extent that I got a garage to put a new caliper on back in January). But if there's something I could check on the work I did, happy to do so! I just don't have enough knowledge to figure out what else this could be, so hoping someone on here can point me in the right direction. Failing that, I'll have to bite the bullet and take it to a garage.

 

Thanks in advance and enjoy the weather everyone!

 

Declan.

[foru2justnv]

Did you wind the caliper back in fully? 

If so and its easy then you shouldn't be experiencing sticking. 

I did on my last change experience it very hard therefore leqrning that my tool was crap hence the advice on the tool. 

In the end i held a spanner on the rewind thing while my son used a breaker bar and socket on end of rewind tool and wound piston back. 

Once wound back i would pull handbrake a few times to pull piston out, then apply a bit of spray grease under the seal and wind back in an out a few times. 

 

If not the caliper on fleebay is not expensive 

[Declan O'Shaughnessy]

@foru2justnvI don't know if I wound it back in fully or not. I wound it until it stopped winding and there was a lot more clearance between the piston and the pads. I didn't want to try forcing it any more in case I did damage! But as I say, the piston is new enough and looked to be in good condition, so I'm not convinced that the problem lies with it.

[Snapper1725]

Are you feeling any kicking through the pedal when braking ? 
Could be a warped disc ?  Possibly try swapping with other side if you can. 

Does the wheel spin freely ? When jacked up, possibly a binding hand brake cable on that side. You could disconnect that side and take it for run or try pulling/pushing the disconnected cable to see if it’s stiff binding 
 

[Declan O'Shaughnessy]

@Snapper1725
There is some shudder on braking at times, I'm not sure about kick. I tend to brake very lightly if I'm honest, unless I misjudge something and have to break hard. A lot of the time I'm coasting to junctions etc. and only lightly braking at the end.

 

To swap the discs I'd have to get the caliper carrier off wouldn't I? I don't think I can manage that without buying another tool (I have the spline bit but my wrenches struggle to fit into the space that's there).

 

The wheel spins freely now (since doing the work on the caliper this morning) but normally it's virtually impossible to spin (same on both sides). I don't know which cable is the handbrake one, but I'll check the service manual and see if I can figure it out and try what you suggest. Probably won't be in the next few days though - waiting for the weather to cool down! Thanks for the suggestions.

 

[Snapper1725]

Most likely yes you will have to remove the carriers ( they are a pig to do, awkward to get at and require M14 spline along with some patience) 

Could be worth a try to see if the disc will come out with it still fitted, something I’ve never tried to be honest.

When I done mine I wanted the carriers off to give them a good clean.