Brake calliper excessive movement?.

[hoobby]

So still have brake problems same brake as before n/s/f blanked off at the hose and the pedal goes firm has been overhauled new piston,sliders,pins pads and boots but have too much pedal movement before they come on its defiantly not air.I think the callipers are twisting due to too much wear on the calliper bush hardly moves when you rock from the top.

 

[Snowy]

The calipers wont twist as the pads will centre the caliper onto the disc.

I have honestly never tried to move my calipers like that so I can't say if that's normal or not.

 

[hoobby]

Just taken the pads out and noticed a lower section on the piston

does it matter which way the cutout faces?.

[Jessopia74]

Looks like slight wear, but it will recenter anyway. Unless your disc is warped and spreading the caliper

[®evo03]

Are caliper faces to hub flat and bolts flat and look ok.

Does the opposite side caliper move like that also.

Didnt someone have trouble with a bleed nipple recently, either blocked, too long or both where different. Or one was too long. 

Are both flexi hoses ok? Read of an internal problem, a defect inside hose.

Cant see why there is a flat spot on piston luke that, is it normal, and what way is the opposite side?

Not overly familiar with later calipers, do they slide on two pins, are the pins right way round, tops and bottoms.

Could a slide pin be worn, or caliper itself?

[Jessopia74]

That machined part in the piston is normal, think it’s something to do with applying pressure with a leading edge to stop judder

[Snowy]

54 minutes ago, ®evo03 said:

Are caliper faces to hub flat and bolts flat and look ok.

Does the opposite side caliper move like that also.

Didnt someone have trouble with a bleed nipple recently, either blocked, too long or both where different. Or one was too long. 

Are both flexi hoses ok? Read of an internal problem, a defect inside hose.

Cant see why there is a flat spot on piston luke that, is it normal, and what way is the opposite side?

Not overly familiar with later calipers, do they slide on two pins, are the pins right way round, tops and bottoms.

Could a slide pin be worn, or caliper itself?

With these calipers I'd be thinking one or both slides are sticking.

[Exclusive Opel]

The cut out section on the piston is supposed to be set using a template but never done myself!

On page 260 of the manual.

[cam.in.head]

yes the caliper piston(if stepped like yours) should be set as shown to stop the brake grabbing but even if its in the wrong position it wouldnt make the caliper twist like that .

first thing i would check is that with the pads removed the caliper can slide freely in and out on the sliders.they are a known issue and rely on the stub axle mounting face to be perfectly flat otherwise they will tighten down crooked ,thus making the caliper seize or be very stiff.

so make sure they move ok first

then reposition the pistons if you can (raised section points towards the nipple if you dont have the correct angle tool)

then check pads are flat( hold up to disc and check they dont rock)

cant see this being a bleeding issue but one more quick bleed on them after its all back together wont hurt

 

[Exclusive Opel]

May sound an obvious one but are the bolts definitely tightening down properly rather than just won't do up any more if that make sense? I'm sure I've had this with rust on the threads or something.

[hoobby]

OK thanks everyone as usual good input and useful info  I pulled it all apart again and went through the lists  everything looks good but top slider pin (both new) has a lot less play than the bottom and is making the calliper twist and jam when moving by  hand  the other callipers movement is smooth and equal.will put it all back and see how it goes but may have to have to get them re- bushed if it plays up again I really can't see what else it could be.

[Jessopia74]

1 hour ago, hoobby said:

OK thanks everyone as usual good input and useful info  I pulled it all apart again and went through the lists  everything looks good but top slider pin (both new) has a lot less play than the bottom and is making the calliper twist and jam when moving by  hand  the other callipers movement is smooth and equal.will put it all back and see how it goes but may have to have to get them re- bushed if it plays up again I really can't see what else it could be.

Have you checked run out of brake discs?

[Snowy]

2 hours ago, hoobby said:

OK thanks everyone as usual good input and useful info  I pulled it all apart again and went through the lists  everything looks good but top slider pin (both new) has a lot less play than the bottom and is making the calliper twist and jam when moving by  hand  the other callipers movement is smooth and equal.will put it all back and see how it goes but may have to have to get them re- bushed if it plays up again I really can't see what else it could be.

I wouldn't bother re bushing them as they are a very poor design. There is a replacement caliper that bolts straight on with a different slide.

The original calipers like to seize for fun.

[hoobby]

1 hour ago, Jessopia74 said:

Have you checked run out of brake discs?

Yes they are straight and true

27 minutes ago, Snowy said:

I wouldn't bother re bushing them as they are a very poor design. There is a replacement caliper that bolts straight on with a different slide.

The original calipers like to seize for fun.

Brake pedal feels good now but can you point me in the direction of these callipers just in case it starts to play up again don't want to keep striping it down every couple of months.

[Snowy]

2 hours ago, hoobby said:

Yes they are straight and true

Brake pedal feels good now but can you point me in the direction of these callipers just in case it starts to play up again don't want to keep striping it down every couple of months.

I am not 100% certain this one fits the manta as there is only one picture, but the replacement calipers are of this design.

https://www.ebay.co.uk/itm/BRAKE-CALIPER-FITS-VAUXHALL-ASTRA-CAVALIER-FRONT-LEFT-LUCAS-TRW-BHV197E/143582681871?fits=Car+Make%3AVauxhall|Model%3ACarlton&hash=item216e31db0f:g:9rkAAOSw4m9cEmm6

[®evo03]

6 hours ago, hoobby said:

 everything looks good but top slider pin (both new) has a lot less play than the bottom and is making the calliper twist and jam 

Is there a difference in top and bottom pin, could they have been mixed up? Are they the same on other side? Can you mount the other slidy part of caliper on other side even if it is upside down, to eleminate needed re- bushed. 

weirdly i have never had front caliper problems, could write a book on rear drums though! 

Out of interest are you running standard wheels? Or alloys?

 

[cam.in.head]

if the caliper on the other side of the car is ok and its just this one i would just try removing the sliding tubes (which i assume you have fitted new ones) and just make 100% sure that they are flat on the bottom ,no burrs and also run a fine file on the mounting area on the stub.any slight uneveness here will make them tighten up crooked.as snowy says they are a crap design and seize up for fun but once working and lubed thay should be ok for a couple of years .as you are tightening them check caliper for movement ( sliding) and soft mallet tap to centralise if needed. once tightened fully up they sometimes go very stiff and this surely indicates a slight mounting surface irregularity. 

obviously they will have an amount of residtance anyway due to the grease and rubber rings but thry shouldnt jam up in any way. 

when you say the pedal has excessive movement unless hose is clamped it sounds like the issue is just with this one side so without clamping it but g clamping the piston itself then you can prove that its all down to the caliper movement issue 

also going right back to your first post ,you say "caliper bush"   you are meaning the sliding sleeve arnt you . the part which you mentioned is new ? ? (sliders)?   just to clarify 

Edited May 24, 2020 by cam.in.head
additional info

[hoobby]

18 hours ago, Snowy said:

I am not 100% certain this one fits the manta as there is only one picture, but the replacement calipers are of this design.

https://www.ebay.co.uk/itm/BRAKE-CALIPER-FITS-VAUXHALL-ASTRA-CAVALIER-FRONT-LEFT-LUCAS-TRW-BHV197E/143582681871?fits=Car+Make%3AVauxhall|Model%3ACarlton&hash=item216e31db0f:g:9rkAAOSw4m9cEmm6

Cheers snowy will check this out but only as a last opinion as I really got a thing about originality

17 hours ago, ®evo03 said:

Is there a difference in top and bottom pin, could they have been mixed up? Are they the same on other side? Can you mount the other slidy part of caliper on other side even if it is upside down, to eleminate needed re- bushed. 

weirdly i have never had front caliper problems, could write a book on rear drums though! 

Out of interest are you running standard wheels? Or alloys?

 

The pins are same all round not going to swap things about as there work great at the mo.oh I'm on standard fit 5 spoke alloys.... there's that originality thing again

4 hours ago, cam.in.head said:

if the caliper on the other side of the car is ok and its just this one i would just try removing the sliding tubes (which i assume you have fitted new ones) and just make 100% sure that they are flat on the bottom ,no burrs and also run a fine file on the mounting area on the stub.any slight uneveness here will make them tighten up crooked.as snowy says they are a crap design and seize up for fun but once working and lubed thay should be ok for a couple of years .as you are tightening them check caliper for movement ( sliding) and soft mallet tap to centralise if needed. once tightened fully up they sometimes go very stiff and this surely indicates a slight mounting surface irregularity. 

obviously they will have an amount of residtance anyway due to the grease and rubber rings but thry shouldnt jam up in any way. 

when you say the pedal has excessive movement unless hose is clamped it sounds like the issue is just with this one side so without clamping it but g clamping the piston itself then you can prove that its all down to the caliper movement issue 

also going right back to your first post ,you say "caliper bush"   you are meaning the sliding sleeve arnt you . the part which you mentioned is new ? ? (sliders)?   just to clarify 

I ran a file over the hubs and slider pin base's and all pad to calliper contact areas now working great pedal feels nice and firm again hopefully good for a few years tho looks like the resistance I'm feeling is the slider boot it stretches and compresses differently to the other sort of buckles flat instead of folding if that makes sense think the rubber has hardened or deformed will replaced.

Will try the clamp idea if it plays up again

"Bush" the part of calliper body the sliders sit in 

I'm now done with brakes onto other things now thanks for the help everyone 🍻.

Edited May 24, 2020 by hoobby

[cam.in.head]

glad you got it sorted. i mentioned sliders etc being new because they come with new rubbers and metal cap and i think most also have a tube of high temp gease too.

have answered your other topic mate too

[Snowy]

6 hours ago, hoobby said:

Cheers snowy will check this out but only as a last opinion as I really got a thing about originality

The pins are same all round not going to swap things about as there work great at the mo.oh I'm on standard fit 5 spoke alloys.... there's that originality thing again

I ran a file over the hubs and slider pin base's and all pad to calliper contact areas now working great pedal feels nice and firm again hopefully good for a few years tho looks like the resistance I'm feeling is the slider boot it stretches and compresses differently to the other sort of buckles flat instead of folding if that makes sense think the rubber has hardened or deformed will replaced.

Will try the clamp idea if it plays up again

"Bush" the part of calliper body the sliders sit in 

I'm now done with brakes onto other things now thanks for the help everyone 🍻.

If you don't use the car much you'll be back in a couple of months.