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Discussion Starter · #1 · (Edited)
In response to a query elsewhere, I thought I'd post this. It's how I fixed an annoying rattle from the front suspension area which my Ampera dealer was unable to even find!

1) Symptoms: Rattle from front suspension driving over bad surfaces. Potholes & water-drains cause rattle,
it's really bad when driving at very low speed over supermarket entrances made of concrete with largeish pebbles in.

2) Diagnosis: reach inside the wheel and grab the central part of brake-disk caliper assembly; you want the bit which
has the piston in and the 2 pads, the bit which actually does the clamping. Shake this around - if you can get it to rattle,
that's the rattle.

3) Fixing it: Jack the car up (hydraulic jack recommended - these are heavy) carefully. I put a plank under one of the strong-looking bits holding the suspension. Remove wheel.

4) If your rattle is on the front disks, you want to undo & remove the TOP pin.
If your rattle is on the rear disks, you want to undo & remove the BOTTOM pin, which probably has a great lumpy thing dangling nastily off it!

In practice, it's a quick job to fix, and if one end rattles, you'll have the same potential problem at the other end, so you may as well do all 4 disks while you're about it.

The description now on is for the front disk, as being most likely to rattle on Ampera. Rear disks are the same, but swap "top" for "bottom" and vice-versa.

Uscrew the pin which retains the clamp-part. Front disks use a 12mm ring spanner, rear ones need an open-ended spanner as the horrendous damper thing's in the way.

TOP PIN SLACKENED-OFF


Rotate the caliper away from the disk, about 2 centimetres is enough, and you can then slide the pin out. There's a rubber gaiter which unclips. Might need gentle taps with rubber mallet to persuade the clamp-bit to swing out!

CLAMP ROTATED


EXTRACTING PIN



PIN EXTRACTED



The holes are reamed to appx 10.00 mm with a tiny tolerance maybe +0.025 mm.
I checked the bottom pin which measures 9.93mm dia and is solid steel all the way along. Perfect.
My top pin (the one you've just removed) measures 9.68mm on the steel bit, and has a recessed end with a rubber sleeve fitted - presumably the idea was to allow some freedom for differential thermal expansion in caliper .vs. holder, and take up the slack & rattles with the rubber sleeve which by now is totally worn out. This pin is a loose fit.

One possible fix is to get 2 new pins of the bottom, all-solid type and fit those in place of the top ones. (Untested). For certain your Ampera dealer won't like this as it's "non-standard", but an ordinary motor factor may well get you pins for an Astra J which should do nicely.

My solution is cheaper, faster & is working well several 1000's of miles later.
You have about 0.3mm clearance between the top pin & hole, so you have space for AT MOST a 0.15mm shim. But this is likely to be too tight a fit. Having now shimmed an Ampera and an Astra J, all 4 disks on each, I recommend using 0.1mm or 0.004" shim steel.

Acquire from a local engineering firm/handy garage, or buy on eBay (enter '0.004" shim steel' and a 6"x3" piece is about £2) some shim steel 0.1mm or 0.004" thick. You want to cut 2 pieces of 30mm x 30mm to do 2 disks, or 4 if you're doing the back as well.

30mm x 30mm x 0.1mm SHIM STEEL



Having cut 2 pieces 30x30 mm, debur carefully and wrap tightly round a circular pencil/similar 7mm dia rod rod & form into a cylinder which clips onto the pin.

SHIM DEBURRED AND ROLLED


PIN BEFORE SHIMMING


PIN WITH SHIM FITTED



Grease & reassemble everything carefully, making sure the shim enters the hole nice & true. The pin should still move in and out reasonably freely - do not use force to assemble! Hand twisting should be sufficient. It's a bit of a fiddle persuading the shim to go back in, but it will go, and gentle prodding with a small screwdriver while twisting etc will get you there. It's important that the shim has no burs or ridges or lips along the edges, so debur all 4 edges, as even the original mfrs edges can have a tiny lip.

REINSERTING SHIMMED PIN



Having fixed my front disks, I've also shimmed my rear ones - these are similar and undersized - but GM have designed a dangly-damper thing for the rears, which hangs off the end of the lower pins. I think this might be the fix for Astra J rear disks which also rattle.

You can save weight (!) by stripping-down the dangly-damper thingy which is also the screw retaining the lower pin, and discarding the useless bits.. Here are some pics.

REAR DISK DANGLY DAMPER


This has two torx-screws holding the large alloy casing together. Remove these, and tap large alloy case with hammer to separate it. Remove the outer half and discard. You're left with the inner half attached to a rubber bushing. Insert into a vice using suitable spacer-rings/wood blocks so you can press the screw shaft through. I'm using a couple of old ball-bearing cases here.

READY TO PRESS SCREW THREAD THROUGH



DAMPER AFTER PRESSING OFF CASING


After this, the rubbery-bit is held onto the pin-retaining screw, so an M14 spanner will undo it.
You are left with this bit, which is all that's needed on the rear disk to retain the pin.

FINAL MINIMAL BOTTOM PIN RETAINER SCREW


Enjoy rattle-free driving! Andy.

:editted 29/May/16 to simplify & improve, add pics, as my experience of these increases...
 

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Perfect. I thought it was just me and everytime I mentioned it to the garage they claimed that it was normal which angered me. I had decided to live with it but this should be easy to fix.
 

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Discussion Starter · #3 · (Edited)
A bit more background info:

Others have said that the Astra J has a brake-caliper rattle, and that there was a Vauxhall Technical Service Bulletin (TSB) 2857 to fix this.

Before I knew any of this TSB stuff, and just after I bought my car (still with about 2 months warranty left) I took my car in for its 3yr service+MOT & please would they fix the rattle under warranty at the same time.

The AMpera dealer claimed they couldn't find the rattle - even though my local dealer had already found it (and showed me) within seconds of putting the car on his hoist, offered to fix it, then found he couldn't as he wasn't Ampera-authorised.:(
When I collected he car after the service, they said they'd "adjusted the back-plate" whatever that means. Maybe, just maybe, there was a tiny improvement. But the rattle was obviously still there. So I took it all apart myself, measured stuff, and the results are as per above.

It's not clear that others are seeing this same problem, so here's a bit more info on what's happened in the past to owners of Astra Js which it seems share a lot of parts with us.


Googling "vauxhall astra Technical Service Bulletin TSB 2857" I see some interesting comments:

"...they changed the dampers and top mounts then finally when the noise didn't go they phoned the techys at headoffice and they said to try braking over the bumps that make the noise and if the noise stopped then there is a newer caliper carrier. I asked him for the update number so I could post on here but they wouldn't give it to me. There's a few on here who have gone in with the same problem with the same noise and they have fixed it with new carriers so it's sometimes definately that."

"...in my case same symptoms it's definitely the calipers rattling because of crap tolerance slide pins.
I can remove the pins, re-grease them all and it's fine for a month or two then the noise is back.
Every other car I've have serviced has close fitting slide pins.
Grab the rear caliper and wobble it through the wheel and you'll find there is enough movement to cause a substantial knock when going over a bump.
Do the same test on other cars and there's no movement.
My issue mainly affects the rear brakes but the front calipers do move a bit too.
Milky2518, I'm astonished you haven't come across this.
My dealer changed shocks, pads, caliper holders, and did the stupid double-sided tape pad fix from Technical Service Bulletin 2857, all to no avail."



So what are we to conclude from all this? It looks to me like:

1) Some (?all?) Amperas have undersized caliper pins which 100% is the cause of the rattle. These pins have a recess with a rubber sleeve, and eventuallly the rubber wears out. Not a good design sadly.:(
2) There's a Vauxhall fix TSB 2857 for Astra J (does it apply for us?)
3) This fix may involve a new caliper carrier :eek:. Why? All it needs is 1 pin. caliper & carrier are fine.
4) This fix may involve double-sided sticky tape :eek::eek: !!! :cry::cry:
5) Some dealers are incapable of (or don't want to) finding the problem.
6) Some dealers have fitted totally un-necessary parts in a failed attempt to fix the problem. Not a problem for the owner if done under warranty, except the problem's not cured & it's a waste of your time & Vauxhall's time & money.
7) The simplest fix with standard Vauxhall parts is to fit the BOTTOM pin (the one WITHOUT the recess & rubber bit)
to replace the TOP pin. This gives you TWO close-fit pins as e.g. Mazda 6 has. :)
8) The simplest DIY fix is to fit 0.004" shims (as I did) to the TOP pin.:):)

My advice?
1) Check to see if your caliper rattles. (Turn wheel hard left, check left caliper. Repeat RHS).
2) Maybe check the rear disk calipers. Mine can be rattled, so I've shimmed them AND saved weight !!! :)
3) If one front disk rattles, best to do both to keep everything balanced & save time later when the other rattles.
4) If your car is under warranty, get the dealer to fit 2 new bottom-pins to the top holes. If he says they aren't allowed to, walk away and get a real engineer to shim them. (Or order 2 bottom pins from OEM car-part supplier and get someone to fit them).
5) If your car is not under warranty, get a real engineer to shim them.
6) If you can't find a real engineer, message me, visit Winchester & I'll do it while you wait.

:editted 29/May/16 improving the figures & advice.
 

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Andy,

I'm an Astra J owner, this rattle rear calliper thing has been driving me bonkers for the last year... So far 2 garages, both independent, but one an ex Vx franchise in Wimborne, have taken £100 off me to 'fix', neither has...

So, as I'm not too far from you, and if you're up for it, I'd love to take you up on your offer to fix properly!

I'm in West Parley, not too far.

Hoping you can help,

Mike
 

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Update on my rattly callipers on my Astra J...

As arranged, popped over to Handy Andy's place where 'we', (I say 'we', it was Andy really!), took the wheels off and had a look at the rear calipers first, way too much play and a rather obvious cause for rattle. Andy slipped the top caliper pins out and found them to be undersized, quick as you like he'd made shims to take up the play. This was repeated for the remaining calipers.

All 4 calipers are now much more solidly mounted and the horrible cheapening and completely car enjoyment killing rattles have gone.

I have also noticed that now the calipers are more solidly mounted there seems to be a lot less higher speed white background noise, the rattle must have been contributing to reduce refinement there too.

In short, the car is transformed, it now feels properly refined and smooth over all rad surfaces.

I can't thank Andy enough, sorted what all the VX dealers couldn't, an absolute top chap, if we both hadn't got things to do I'd probably still be there chewing the fat as it were!

Again, thanks Andy,

Mike.
 

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So, after 12 months of rattling from the front wheel of a Astra J I decided to try this fix. Bought some Shim steel off eBay £1.95 and put it both on the front wheels, top calliper pins and NO MORE RATTLING . Finally nice and quiet over bumps. Thanks for the tip.
 

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Well few weeks later rattle is back!
Front ones ratting and back ones now I've changed the discs and pad at back . I'm at my wits end Googled Astra j rattle and there are post about it so must be a problem. After buying new pins for front left wheel still rattles but I've noticed the piston isn't pushed against the pad and a bit of play in that. Not sure what to do now just phoned pentagon they won't tell me anything just want it on for diagnosis witch will cost me. Just thinking of getting something stuck to the back of the pad were piston is to make it thicker so no play there?
 

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Discussion Starter · #9 ·
Adrian, this stuff isn't rocket science! In your position, I'd have the wheels off and again try to decide where the rattle's from. Maybe the shim has worked it's way out somehow? It's only thin stuff after all. I just changed disks & pads on a C1 yesterday, and having watched the youtube video to refresh my memory, I noticed that the man applied a small smearing of grease to the back of the pads, and also a smear to the circular bit of the piston where it touches the back of a pad. The parts I bought didn't have any grease with them, so I used some copperslip, rated to 1100 C so should be ok I reckon.
I'd suggest you do the same, just the faintest smear on back faces may help "glue" them & reduce rattle.

The C1 pads have a couple of spring-steel clips, one at each end, which I suspect help stop rattles - I don't know if the Astra has anything like this? These clips will in effect retain the pads in whatever position the piston left them.

A small gap between piston & pad is to be expected - during braking, stuff heats up & expands a lot, then cools after, so I would expect a gap to appear. Also it's pretty easy to push a piston back into the cylinder, so the slightest wobble (play in wheel bearings, disk v slightly warped etc) in the disk as it rotates will do a bit of piston-pushing. That's not the problem you have. Putting a solid layer of something behind the pads won't get rid of that gap, it's self-creating & self-adjusting.

Buying a replacement top pin with the rubbery thing in isn't going to solve the rattle - the excessive clearance will still be there. But if you buy a replacement bottom pin & put it in where the top pin is, you will in effect have shimmed the original, but rather more thouroughly/sturdily, so that's worth a go. Especially if your shims have worked their way out somehow!

Whereabouts in the country are you based? you're welcome to call in if near me in Winchester!
 

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Seem to have sorted the rattling out. Back shock absorber that black tube around it rattled when moved so just stuck some foam in. Greased up pins again and tryed to tighten like it says on Vauxhall how to website. Drove up and down my road and seems to be 99% gone. Let's hope it lasts. Thanks for your help.
 

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Hi,
the rattle returned . But I tracked it down. It was one of the two bolts on the caliper. They both need that sheet metal round them to stop them moving and rattling. It was to thick to go in the hole so I just cut a thin strip and wedged it down one side of the bolt and job done. Hopefully I won't be back. Thanks again.
 

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Discussion Starter · #12 ·
Ouch! on my Ampera, one of the bolts is a "precise" fit, and didn't need shimming. The other (with the recess & rubbery stuff) is undersize and needs the shim. Sounds like your other bolt is maybe a tiny bit worn - maybe the whole thing rattling around has hammered the hole a bit & made it larger! But glad you got it fixed. You can get shim steel down to about 0.001" thick - I used 0.004" thick on your undersized bolts, so why not get some of the thinner stuff (say 0.002" & 0.001") & have a play?
 

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Hi
I bought new oem pins for front. The pins are 9.6 (for top) and 9.7mm diameter. So assuming the hole is 10mm, than even this 9.7mm pin meant to be on lower side, won't be enough for top side? And one is already corroded. And i bought more expensive ones.
Thanks for this instructions
 

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Discussion Starter · #14 ·
I suggest re-check dimensions with a micrometer. New pins should not be corroded - get them changed if rusty, if you can. Otherwise polish up with the finest emery paper. You may need to get some additional, thinner shim steel from eBay.
 

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I measured again with two more micrometers. 9.60 top pin and 9.77 bottom pin. This are new ones. The difference is 0.17. I use digital meter. It seems even difference is smaller than at original. I need to compare with original. Maybe those new top ones are thicker. Or they are even slimmer.
 

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Ok. I couldn't locate any local company here to get this shims. So i was thinking and checking in garage what I have on disposal. I found and my dad suggested if i can use aluminium tape (0.05mm thick) to thicken the pins to right size instead of using shim. What do you think? Maybe to get to 9.90mm?
 

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Discussion Starter · #17 · (Edited)
I have no idea how long aluminium would last. I bought shim steel on eBay ; "shim steel assorted pack" and "shim steel assorted pack" will find you some around £10, or you can just order single sheets for less if you prefer. Most have 0.002" as thinnest, but one seller also had 0.001" available so I got a sheet of that also. Your 9.77mm pin, call it 9.8, would take in theory a .1mm thick shim all round, = 0.004". so probably 0.003" shim would fit nicely. It helps to leave a tiny gap when asembling! The 9.6 pins would take max .2mm shim =.008". so I`d use 0.006" myself.
 

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Ok, so today i checked it. Both pins have some play. The new pins are 0.1mm thinner than original.So I did this: On right side I installed both pins with rubber, new ones. On left side I installed both pins without rubber, old ones. On right side now when in bang on tire it doesn't ratlle. On left side it is much better than before, but not as good as on right side. I will se tomorrow when I will be driving how it goes. If right side will be good, I will instal both pins with rubber on left too, those are much more tight fit than the other ones.
 

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ok, here it is. Right side with both pins with rubber sleeve was completely silent, so now I installed those on left side too. Now it is completely silent on both sides.
 

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Discussion Starter · #20 ·
Excellent. I expect it will be fine, until the rubber starts to age ... ! Feel free to do the same to the rears if you like, though they seem to rattle a lot less for some reason :)
 
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