Disc brake conversion problems- SORTED

[silverboydreamer]

I have installed the CSP products disc brake conversion kit for my ‘B’ but after 150 miles using the discs I am getting mild to severe vibrations when braking. It appears as a mild vibration when the discs are cold and increases to a judder when hot, I think it only occurs on a gentle to moderate pressure on the brake pedal , when hard braking is required there is no evidence of the judder. I have also changed the master cylinder to a dual circuit one made for discs at front and drums at rear, whilst the kit is of high quality I have found the response fro CSP rather lacking, they say the pads are over efficient and the problems are with the suspension. I have recently ( last year ) finished a total refurb of the car including brakes/suspension and I know the king pin was also refurbed shortly before I purchase the car so I don’t think their reason stands up.
Has anyone else fitted this kit and experienced this problem?, if so have you found a solution to the problem?.

[BD55]

I take it all the bolts etc are still tight? Maybe worth taking them off and checking everything is seated properly. But it does sound like the discs maybe warped or running out?? Also check your link pins are adjusted up.

[silverboydreamer]

Hi,
I have checked fixings etc and all tight, there is a little play in the floating callipers but that looks like it’s part of the design, link pins and wheel bearings checked, tyres are new and balanced. After your suggestion I looked up ‘running out‘ and from the descriptions of running out symptoms, it’s seems to fit the bill, particularly thermal judder, will now look at discs to see if there are any signs of hotspots etc, if not will try and find a way of measuring the disc for trueness, I’m surprised that the judder started so soon after 200 miles and a careful run in.
Thanks

[Bruce M]

I’d start with measuring the run out of the disc with a dial indicator. While your there, use it to set the bearing preload to spec. Only needs a slight angle due to dirt, machining burr, etc to cause judder, especially with two part hub/disc set ups.

[silverboydreamer]

Hi Bruce, how do you preload the bearing, the washer supplied is a tight fit to axel so unlike 911s which has a larger hole and you can tighten the clamp until you can just move the washer, on 356 I have tightened the clamp up and then turned back a bit before tightening off the clamp.

[mycar]

Here's a general tick list from Ferodo.

https://www.ferodo.co.uk/support/light- ... udder.html

[Bruce M]

Hi Bruce, how do you preload the bearing, the washer supplied is a tight fit to axel so unlike 911s which has a larger hole and you can tighten the clamp until you can just move the washer, on 356 I have tightened the clamp up and then turned back a bit before tightening off the clamp.

Use a mag stand with dial indicator, attached to the disk surface & with the dial indicator reading off the end of the spindle or nut. Push & pull the disk in an axial direction to read the play in the bearing. Adjust & re-test until the measurement is in spec.

Similar to this (excuse the non-356 reference but you get the idea)

[silverboydreamer]

After checking runout which was less than 0.05mm and bearing preload, I got in touch with CSP explaining I had thermo juddering and I thought the pads were at fault, they tied to blame the cause as worn running gear. After I explained the suspension had been recently been restored to factory settings, they offered a different type of pad which was shipped to me and fitted to the car, I have done 150 miles with them and no sign of juddering. So if anyone converts their 356 to discs using the CSP kit ( a well made one and experiences similar problems to mine go direct to CSP. Thanks to all who contributed!

[neilbardsley]

Glad you got this resolved

Sent from my Redmi 7 using Tapatalk

[merbesfield]

Do you still recommend the CSP kit? Just starting my research. Mine is a 57A.

[Ignatzcatz]

I know CSP do some nice stuff, bit expensive. I swapped in some 944 disc brakes mainly because I wanted 5's on 130 so I could run Fuchs. I just machined up some adaptors for the calipers and it all bolted up. Real good brakes too, I could lock the fronts up at 30.

[silverboydreamer]

Have done over 1200 miles this year with this disc kit, after initial juddering problems the brakes have performed very well, I would recommend the front discs kit that I fitted with the proviso that the pads supplied may cause a problem. However if you do experience similar problems to mine contact CSP who can provide an answer.

[merbesfield]

Does anyone make a kit for the rear brakes?

[silverboydreamer]

CSP makes front & back kits, see
https://www.csp-shop.com/en/csp/disc-br ... 0676g.html

[merbesfield]

CSP makes front & back kits, see
https://www.csp-shop.com/en/csp/disc-br ... 0676g.html

Thank you. All I need now is to rob a bank.