Help brake cylinder stuck while replacing pads what do I do now.

[Vince70]

I wonder if someone could give me some advice I decided it would be the ideal day to replace the rear pads on the Ronda 400 as money is a bit tight but I have plenty of free time so rather than take it to my trusty garage I thought I might as well have a go myself using my trusty halfords toolkit.

 

I've managed to disconnect the handbrake cable and remove the pin and disconnect the carrier and so I decided it would be a good idea to pump the brake pedal then take the lid off the brake fluid reservoir then lube the piston and push it back in.

 

Well this seems it didn't go to plan as the piston is now stuck solid and I've tried all kinds of hammers and screwdrivers and I'm not having any luck so I wondered if I'm doing something wrong, Also I can't undo the bleed nipple as that's rusted in solid and no amount of 10 or 11 MM. sockets or its imperial equivalent wants to fit on it as it seems that's knackered too.

 

Here's where I'm at.

 

 

Also the brake pads are exactly the same size but the old ones have an extra bit of metal on the back.

I should of left it to the professionals and I'm not talking Bodie and Doyle.

[BeEP]

Apologies if teaching grandmother to suck eggs here, but I think the piston needs to be wound back in rather than pushed.  They certainly did on the 420 I owned.  I borrowed the correct tool (which isn't much of a tool and costs pennies!) but I'm sure you could improvise.

[Junkman]

Looking at the surface of the piston and the general condition of the rear brake, I coudn't possibly throw that rubbish far enough away.

[Vince70]

I've tried turning it with a pair of mole grips but to no avail and I've got one of these things but it's too large for the caliper.

[Vince70]

So is it a new caliper and disks.

[BeEP]

I've tried turning it with a pair of mole grips but to no avail and I've got one of these things but it's too large for the caliper.image.jpeg

 

That looks the same as the tool I used.  The pins on one of the sides should fit.  Agree the discs look past their best but don't see why the caliper can't be cleaned up and re-used; assuming you can get the piston to move!

[steveo3002]

you know its push and turn yeah?

 

something like this

 

http://www.ebay.co.uk/itm/BRAKE-CALIPER-PISTON-REWIND-TOOL-LEFT-HANDED-SET-WIND-BACK-KIT-UNIVERSAL-CT3330-/322435565020?epid=1805387743&hash=item4b12a845dc:g:75kAAOSwIjJZQR3B

[sierraman]

Sometimes the calipers are handed, opposite threads. Farting about with pliers might end up slipping and then tearing the seals.

 

The piston shouldn’t come out as far as that, I’d look for a used caliper. When they are stuck in sometimes you can release them by using an air line.

[SiC]

Probably not recommended, but I've used a fat allen key to wind a rear brake caliper piston in before. My concern on that caliper is the rust on the piston and any damage it might have done to the seals as its was being forced out.

[MikeR]

extra bit of metal looks like a low pad warning to me . as for the piston . its rusted. and may of come off the internal screw with being so far out .might be wiser to shop around

[spike60]

In my experience pistons with cut outs like yours or a hole for an Allen key in the middle do need winding back in as previously said. The piston also needs to be straight in the bore or it won't go back, it'll dig its heels in. As previously said may be LH or RH thread depending on the handbrake adjuster mech inside the caliper. Gently polish all the grot off the piston before pushing it back. When you put it back the tit on the back of the piston needs to be lined up with one recesses in the piston or you'll have a dragging brake.

My wind back tool looks like this, it lets you load piston as you rotate it.

 

[Vince70]

I've got the piston out now I just can't get it back in the caliper now lol.

[derskine]

The rust on that piston looks like it'll give rise to sealing issues at some point, brakes are not something you want to be risking this on.

[Vince70]

I've cleaned up the piston as best as I could with some wet and dry and got the piston back in and it's turning nice and freely now.

But I think it looks like it needs a new caliper really so once I've got some money that's the first thing I'm going to do now.

[sierraman]

I’d be surprised if it seals properly, it could end up pissing fluid all over your new pads.

[Mally]

I've seen worse pistons, and if it was me I'd try it.

But I can't recommend that you do.

If you are worried about the extra bit on the pad you may be able to remove the rivet from the old pad by tapping a small screwdriver under the head.

Sometimes the extra bit is loose in the box.

[steveo3002]

see if u can crack the bleed nipple before fighting to reassemble it then cant bleed it

[Cleon-Fonte]

So is it a new caliper

 

I'd say so.

 

see if u can crack the bleed nipple before fighting to reassemble it then cant bleed it

 

This. I always loosen the bleed nipples first just so I know everything else I do isn't a complete waste of time.

 

If the bleed nipples refuse to move heat them up with a blowtorch then smother them in a wet cloth. I've found even French bleed nipples tend to pop out easily enough using this method.

[Dead_E23]

As long as the bore appears to be in good condition, I would consider rebuilding it with a kit from ebay.    Including the piston, they're £15 - 20 a side vs ~£80 for a recon caliper.    Annoyingly, the kit doesn't include a bleed nipple - but they can't be much.

 

Take the opportunity to buy yourself a tin of red brake grease.   The man in the local motor factors (who don't stock it) told me that not many places will sell it because they'd rather you bought a recon caliper.   I was very impressed with how it transformed a seized caliper on my V70, so there might be a grain of truth in that.

[Vince70]

Thanks for the help I don't know what I would do without the help of Autoshite...

Its all back together and working ok for now so being a tightarse I'm going to go for the rebuild kit as it should come apart easy or I will be keeping a lookout for a NOS bid job off eBay.

[SiC]

Maybe leave pressure on the brake pedal overnight? That way, if it has sunk during that time, you know its not sealing properly.

[Mally]

Maybe leave pressure on the brake pedal overnight? That way, if it has sunk during that time, you know its not sealing properly.

 

Reminds me of a post on the Rover 75 forum.

" in readiness for my upcoming MOT I pressed my clutch pedal for 30 minutes to see if it leaked"

[twosmoke300]

I would hope all of you are pressurising the system to check for leaks after all brake work !

[Guest Hooli]

I would hope all of you are pressurising the system to check for leaks after all brake work !

 

I hold the pedal down to see if it feels ok & then go for drive. If I don't die they probably work.

[beko1987]

I always do a short distance emergency stop after brake work. Especially after I did the Zafira rear pads and forgot to bleed it through... Amy came back 5 minutes later pissed off as she nearly didn't stop for the first roundabout from our house. Ooops

[twosmoke300]

I dry off any disturbed unions with brake cleaner and an airline / blue roll . Then start her up and hold pressure for 30 secs at least ( using an assistant or pedal holder ) . Then go round and look for any small weeps.

[vaughant]

Sounds like you've done an alright repair there. It will seal fine, there's a decent amount of tolerance in piston seals because they do move in and out and obviously go from freezing cold to very hot reasonably quickly. I always give the outside of any exposed piston a quick tickle with the old wet and dry, after all, 1000 even possibly 800 paper can still yield a good shine in paint after polishing so as long as you're not using 80 grit sandpaper I see no further issues.

[Guest Hooli]

I dry off any disturbed unions with brake cleaner and an airline / blue roll . Then start her up and hold pressure for 30 secs at least ( using an assistant or pedal holder ) . Then go round and look for any small weeps.

 

I do tend to give everything a glance after the test run to check it's all dry too, I'd forgot I do that till I read your post.