82 replies to this topic

[Jase_MK]

I find all this twisting action a bit strange. Not saying any of you are wrong as I'm yet to do my rear pads, just sounds odd that's all. Surely if the new pads are 2cm thicker than the old ones then the piston gets screwed (!) back 2 cm into the thread it is housed in. Then 18 months later it is another 2cm forward due to pad wear so you screw it back another 2cm into the thread that it's housed in. So the threaded part of the caliper that is holding the piston, how long is it? Surely you can't go on screwing the piston back and back and back forever? I am assuming the piston doesn't screw iteself (!) forwards during normal brake operation/self-adjustment ? Am I just being thick? Does anyone understand what I am talking about?

[Steve Crisp]

Hi Jase, I think it's more to do with not bunching up the seals as they go back into the bore. If you can visualise a sink-plunger inside a pipe, then pushing the plunger forwards will make the plunger grip the walls of the pipe tighter. Turning the plunger stops the plunger edge biting and bunching up. It's the same for your seals in a bore. A straight push will mess the seals up, but turning them as you push them in will allow them to retract easier, and won't turn the lip of the seal over. It's not on a thread. You can turn either way... Steve

[Jase_MK]

Got ya. cheers Steve!

[Tony]

IMHO, IIRC etc Isn't the twisting of the piston to wind back the self adjustment on the handbrake. Each time you use the handbrake, it winds out a very small fraction as the pads ware. When you put new pads in, you have to undo all all this self adjustment. Could be totally wrong though Tony

[Macca]

Think youre right tony. Thought i'd bump this to bring it nearer the top of the posts as im attempting the rear pads this weekend

[P11 COV]

Oh, forgot to mention...

Obviously, have the hand-brake released through all this!

Sorry, Ricky, I beat you to it, but there again you beat me to doing the front instructions!

Where is Martinh? - I miss his inane comments - did he really exist -did anyone ever see his Hotel in Brighton?

[P11 COV]

Quote Martin h - Why can't we have porn instead of pictures of brake pads

Where is Martinh? - I miss his inane comments - did he really exist -did anyone ever see his Hotel in Brighton?

[Whiteboy]

Steve

[vee ex]

Can someone help me here....
Steve states:

Fit the new pads, replace the pin and spring.
Tighten up the 17mm bolt fully.
Refit everything else, etc.

When I used to do this kind of thing many years back...(yeah yeah old git me) I always put a dab of some kind of thread lock (Loctite)? on the bolt to make sure it wouldn't come undone due to vibration... is this needed now or not? Just that as it's brakes better to be safe...... as it were

[Macca]

Fitted my 1144's after work tonight. Took just over an hour to do all four corners Cheers for the write up Steve

[DanDare]

Great Macca, You can show me how to do mine when I need to do them. Dan

[Mercenary]

I can't seem to hinge back the rear caliper as shown in picture 5. All steps previous to this have gone okay - the outer brake pad is out and I can move the caliper side to side, just not backwards! Help! Thanks. Paul

[Rod]

I can't seem to hinge back the rear caliper as shown in picture 5.

All steps previous to this have gone okay - the outer brake pad is out and I can move the caliper side to side, just not backwards!

Help!

Thanks.

Paul

Try the bolt holding the caliper on an the bottom.

[Mercenary]

The bolt with the allen key head? I have tried to undo that but it is hard to access due to the brake cable so I can only use the rounded end of the allen key - and I do not want to apply too much pressure... Is this the correct bolt? Does it definately need to be removed? Thanks. Paul

[Whiteboy]

You need to remove the top 17mm bolt and then tap the calliper back away from the disk if it is stiff "Have a second look at page 1 picture".

[Macca]

You only need to remove the upper 17mm bolt. If the calliper wont hinge on the bottom bolt and fold downwards it is probably because the top of it is still located on the collar where the removed bolt goes. The calliper bolt hole locates onto a hollow pin (about 5mm long) which is the threaded part of the mounting bracket that the bolt screws into. Slide the calliper towards the centre of the car to free it from the locating pin then the calliper should fold down. Hope this makes sense

Edited by Macca, 04 December 2004 - 09:08 PM.

[Mercenary]

I gave up and drove it to Formula 1 in Milton Keynes to get them to look at it. It took 4 of their grease-monkeys 30 minutes to take the caliper off... The they didn't have the correct tool to twist the caliper piston (they couldn't do it with pliers) - so they put it all back together again (which took them another 15 minutes). They asked me not to take it back there again for the rear brakes Macc and Whiteboy - you have confirmed what need to do. However when you say 'tap' I thnk you actualy mean 'hit with a sledge-hammer' Anyone know what size 'Piston retraction & turny tool' I need? I might invest in one to make the job easier! I will have another go tomorrow! Many thanks. Paul P.S. - 'Clarkson night' is on right now on UKTV People (channel 566)

[Macca]

Macc and Whiteboy - you have confirmed what need to do. However when you say 'tap' I thnk you actualy mean 'hit with a sledge-hammer'

Anyone know what size 'Piston retraction & turny tool' I need? I might invest in one to make the job easier!

I will have another go tomorrow!

Many thanks.

Paul


P.S. - 'Clarkson night' is on right now on UKTV People (channel 566)

If the garage managed to release the calliper then it should come off a bit easier at the next attempt. Sounds like you've had a bit of corrosion causing the lug/calliper to sieze together. When i did mine i used a pair of longnose pliers or circlip pliers. just opened them up so that i could insert the two prongs of the pliers into the holes in the piston body to turn it.
Just a word of advice if you have ago yourself, I think that you have to turn the piston anti-clockwise on one side and clockwise on the other side of the car. I may be wrong (while since i changed mine) Can someone confirm this please?

Shame you dont live locally to me as i would have given you a hand to change them

[Ricky2772]

there is a specific tool to retract the piston, being sold by eliseparts for few quids......... Rear brake adjusting tool £ 11.69inc makes life much easier... before going clockwise, pre-soak the piston with WD-40. remember to PRESS on the piston as well as turning it. make sure the rubber skirts are not cut/damaged, otherwise repleace'em immediately!!

[Jase_MK]

The reason the caliper doesn't go back that easily is usually because the discs are a little worn. The very edge of the disc has a lip that sticks out about 1mm or so. Because the pads sits so close (touching) the braking surface of the disc, swinging the caliper back involves the pad surfaces having to get over that ridge/lip on the disc first. That's what I found anyway. Took lots of knocking with a hammer and something soft to sort it out. edit: Just seen you've already removed one pad, so that's not the problem. I'll leave the above description there though in case anyone else has that problem. A good pair of needle nose pliers should be fine for the piston if you can't find a special tool. I've done two different VXs now with these and they work pretty well.

Edited by Jase_MK, 05 December 2004 - 01:07 PM.