288 Calipers - pad slap/clonk ?

[_Matt_ 32]

Hi,

I'm getting an occassional clonk that reverberates through the spring. I can't make it do it by swerving on the road, moving about on the drive or by physically moving components with a breaker bar, but it seems to happen after the brakes have been applied and let off i.e. reversing off my mums drive - clonk, pulling out of a junction after coming to a stop - clonk. 

Initally, and before I noticed it was after the applying the brakes, I thought it was probably ball joint related so changed them last weekend. I suspected them anyway because I bought them second hand (unused) in a parts buy and the steering at speed didn't feel as tight as it did prior to fitting those parts. That steering issue has been fixed with the replacement ball joints but the intermettient clonk has not.

Prior to all of this I had a bit of work done on the corrado last month after that work the clonk appeared - new top mounts, new ball joints, new bearings and the fitment of Big Redd refurb'd 288 calipers. Most of the other components have less than 3,000 miles on them (outer cv joints, inner and outer track rods, all bushes, shocks and springs). There is no movement in the usual 3-9 and 6-12 rocking and no play with a breaker bar on the bushes or any play on the shock / spring on side to side movement.

Probably should have just done the work myself since I am having to do it anyway but was trying to save time and wanted the car nice for summer, plus having faught removing the driveshaft from the hub on a mk3 5x100 car i did not want to be in the same place with the Corrado - they glue them in from factory!

Anyway history over - I am now suspecting the calipers and pads not retracting properly causing the clonk on release. Anyone had this - is there something better than copper grease for the ears of the calipers assuming it that? 

Cheers 

Matt

 

[fla 9]

I find that copper grease dries up quite quickly and prefer to use ceramic grease, like cera tec. Just bought a big tin of the Granville ceramic grease, more cost effective than tubes

[Dox 23]

The spring thingy is fitted to the outside of the caliper?

[_Matt_ 32]

Cheers! 

The springy thing - ah yes it is now BUT I forgot to take it with me to the garage so had to drive back 80 or so miles without it. I went to Stealth as they did lots of work to car previously and wanted a once over as well, I know seems mad driving that far for this type of work. 

I'll grab some ceramic grease in the meantime as it sounds like its time to strip them off and refit. Mayve the pads shifted out of shape without the springs in place now you mention it.

[fendervg 33]

Check none of the pistons are seized - the front pads should also have a spring clip with 3 legs attached on the pad facing the piston that sit into the pistion seat itself.  Also the calliper sliding pins should move freely, especially on the rears. 

[_Matt_ 32]

Is that on the 280s fen? I don't think the 288s have he spring clip like that. The calipers them selves are freshly refurbished by Bigg Redd, i will check the slide pins for good measure but hoping they've done their job right! 

[Dox 23]

288s will have the clip into the piston. The carriers hold the pads, were thes refurbed / new?

[_Matt_ 32]

Yeah refurbished at Bigg Red but they were used before hand. I'll strip the off and reinstall as next game plan - those front springs were not installed for the first 80 miles and I can see the piston section could rotate without them. Maybe that has happened and they are out of alignment.

 

Edited May 4, 2022 by MJA

[_Matt_ 32]

another pic - this was taken when i got home and put the springs on

 

[fendervg 33]

Yeah, the 288s should have a spring clip bonded onto the back of the inner pad that sits into the piston. Are those spacers on there? Just wondring if they coudl be causing an issue with clearance, but unlikely - assuming you are runing 16/17s

[_Matt_ 32]

Ahh i see, i'm not on the locating lugs assume so - Vince/team fitted them. 

They are 20mm spacers matching bolts for oem speedlines. The wheel weights were hitting the calipers intially so tthat and aesthetics was the reason to fit. I do have 16s as well that don't require the spacers - worth a try to swap them over as well. I do torque the bolts to 120nm.

 

 

[1xshaunx1 27]

Grab hold of the engine and see if it moves a bit more, I’m thinking engine mounts or something is loose

[fendervg 33]

I run 15" OEM Speedlines with 288s with no fouling issues - it's tight, but the tyre shop just used a different profile balance weight and put somewhere else on the rim.

 

Edited May 4, 2022 by fendervg

[_Matt_ 32]

I'll check the mounts good shout but do have new mounts at the back and a VT at the front.

Yeah on the 15s I could have got the weights moved but I wanted the wheels spaced out anyway.

The noise does come from either side of the car when it happens - like when I reverse of my mums drive it is always on the pass side as I turn the wheel left to exit. When I pull out of right hand junction it happens on the drivers side :S

[1xshaunx1 27]

Bushes or bolts on the wishbones,? you need to give things a shake and look underneath 

[_Matt_ 32]

Yeah i've done that with pry bar and shake around - also put another thread up re torque for rear wishbone bush - never touched it on this car but am working on my mk3 and am not sure what the rating is. Also the bush is also fairly new and a Leon Cupra R/R32 solid rubber bush.

[1xshaunx1 27]

Have another shufty 

easy  to miss stuff when you’ve been doing a fair bit 

[fendervg 33]

Some torque settings to be found here:

https://wiki.the-corrado.net/torque_settings_and_bolt_sizes.html

[_Matt_ 32]

Cheers I'll check the torques and play - i don't think that link has the torque for the wishbone bushes unless I am blind (could well be.. ). 

 

[_Matt_ 32]

Cheers I'll check the torques and play - i don't think that link has the torque for the wishbone bushes unless I am blind (could well be.. ). 

 

[fendervg 33]

For 4-cylinder cars

Edited May 4, 2022 by fendervg

[fendervg 33]

This one for the VR6 "plus-achsel" wide track suspension

Edited May 4, 2022 by fendervg

[Dox 23]

I've seen bushes that literally fall through wishbones being slightly undersize causing a knock on a neighbours A3.

 

Toby can have issues with people reproducing diagrams from manuals (not naming names as their searches look for such names).

[fendervg 33]

I can remove if needed - I think one or two pages should be fine for fair use, it's not the whole book after all. Plus I can prove I own one and paid for it. If it's an issue let me know. Save as

[_Matt_ 32]

mega thanks on that - took copies if you need to take it down.

Interesting so it's 18 i am referring to 70NM + 90 degrees but on the mk2 it is 130NM for all wishbone bolts. That is quite some difference. I'll check everything on my Corrado for torque with this info.

It is going give me a headache on my mk2 16v (ABF block, KR fuelling) where I am installing a mk3 subframe with 4x100 arms - i guess i will take the 130NM route. Having fouling issues with bonnet and mk3 rear engine mount can be chopped down if needed to aid clearence.  

 

Edited May 4, 2022 by MJA