Cupra Front brake pads DIY

mgrays

Active Member
Dec 9, 2006
371
18
Aberdeen
Well I read the stories on here.. and chose to ignore them:redface: .. well mostly..

Take them to a garage if not technically pretty competant .. if you are happy with repairing their damage (I am not.. so DIY and do it right once...:whistle:)

In another 3 years time there will be articles on replacing alloy AP 4 pot caliper with more reliable single pot Golf calipers (heavier but far more robust from salt) .. these AP calipers are a time bomb of corrosion.. the bridge bolts are stainless but the bridge tube is zinc plated; add winter salt and it is a pure battery of corrosion with aluminium, stainless and carbon steel!! Funny.. AP keep advertising for a Brake Engineer for car applications .. they need to learn a bit more first ... and I'm not applying!




So .. for a nice whole afternoon job!:cry:



Fitting Cupra front brake pad change (AP calipers)

Note .. you will not remove these by just chapping out the pins .. the pins will not move with a 3.5mm punch (you cannot get enough energy into such a small area to overcome the corrosion that will occur) .. so you have to cut them out.. the Seat know this as they recommend fitting kits with new pads.

1. remove caps and slacken wheel nuts
2. Jack up car and place on axle stands
3. Lubricate bridge bolt and pins where they pass through the caliper body.
4. Grind off lip on disc on outside (THIS IS OPTIONAL but helps job and improves brakes)
4.1. DANGEREOUS .. do this at your own RISK
4.2. Start car and place in 1st gear; this will gently rotate discs (if you only have one wheel jacked up then it is not so safe as the differential will not limit the force generated)
4.3. Ensure you have NO hanging clothes etc…
4.4. Using the caliper body as a rest and placing the grinder so the disk is parrallel to the disk then grind off the lip. Not a deep heavy force but a reasonable one.
4.5. When you just see the pad area by the lip start to change colour you have gone far enough; there will be very light grind marking but they will go in time .. think of it as DIY grooves!
4.6. Do this at outer lip and on the inner lip by the wheel bolts
4.7. Do the very outer surface too
4.8. It will be very dusty/dirty so consider breathing protection on top of face/ears. Mostly brown rust but some brake pad dust and all bad for you no doubt.
4.9. When finished the pads can now easily slip out of caliper instead of your having to batter them past this lip
4.10. This will also improve brakes as there is less dragging from this area
5. Remove Bridge bolts;
5.1. if bridge tube turns then try and hold it with mole grips; note the capscrew bolts are stainless so they are soft.
5.2. If they fail to come undone then the bridge tube which is zinc plated steel has probably corroded itself to the bolts.. use grinder to remove a long section of the tube (tip the steel will turn blue just as you grind through), rotate tube/bolt and grind another section from tube (note you will not be able to remove last 2mm beside caliper body). Then use screwdriver/chisel to split tube and as it collaspes inwards it will split on the uncut section and come away from the bolt shaft. It will damage the aluminium of the caliper body but then this will already show signs of corrosion so the damage is there already!
5.3. You can get a good hold of the bolt head with molegrips and combine this with the allen key to improve the torque to remove bolt.
6. Lever pads back off disc so that the pistons retract to protect the bolts
6.1. You can normally get a screwdriver in at the top/bottom of the pad by angling it up by 45 degrees and then levering.. but do not use excessive force or you will bend the disc.
7. Lever pads back onto contacting disc
8. Lever pistons back into caliper housing; you should have to do this a few times as each time you lever one in another will come out.. use a couple of screwdrivers. Watch out for damaging rubber boots and ensuring you do not “****”/twist piston in their bore so lever both sides. If pistons are twisted you can use brake pedal to pump them back out. You can also use this to “work” pistons that are siezed/stiff.
9. Using good quality hacksaw blade cut the pins using the back of the pad’s steel plate as a guide; you can do this from the middle of the pad up/downwards but make sure you do not damage the piston boots. This will leave a stump of the pin so that you can work it but it will allow you to remove the pads on the pins as one lump
10. Remove the pads/pins as one part; Work each side, you can get a lever in at the top at the back to lever and a direct hit at the front. Watch the caliper body as they are delicate. If you have removed the lip from the disk this will be far easier.
11. Remove the remains of the pins
11.1. Outer pins need 3.5-4mm punch and drive into where the pads where.
11.2. Inner pins; drive them 0.5mm out to where the pads where to get them moving and then reverse and drive in towards engine/gearbox with 6mm punch followed by 3.5-4mm punch. This is awkward as you cannot get a straight hit on the pin and you may want to dress the pin edge up once you have got it moving so that it does not damage the aluminium body.
12. PADS ARE OUT!!:funk:
13. Clean up the inner edge of the disk that you cannot get a grinder with.. use small chisel and work slowly over 3-4mm section at time in gap at top where caliper bolts to upright; you can only get 12mm section per rotation so this takes time... Occasionally you will need to push some of the rust lip in from above if it does not break off.
14. Clean up stainless slides where pads rest inside caliper. Look for corrosion which may push these plates up.
15. Test fit pads; the stainless slides are designed to be sprung slightly to stop the pads chattering/clunking. I prefer my pads gently free sliding so I grind the top surface of the pad steel backing plate until the pads move with just a little drag; this should not be more than 1mm max and if it is then you need to consider removing and cleaning under these stainless slide plates which means removing the caliper..
16. Clean all the holes, inspect bridge bolt threads, clean up bridge tubes if they are acceptable; bolts should be a easy sliding fit with no drag. I had to clean up threads on bolts and body with M8 tap and die on passenger side (this is always the worse side as it runs in the gutter)
17. Paint if required (caliper and disk ground areas)
18. Lubricate sliding areas and holes/threads ensuring nothing goes on disk (use petrol/paint thinners if it does). Put some on back of pads where pistons rest.
19. Put pads back in; note Arrow on back points down so the taper edge is at top of pad
20. Put bottom pin in by hand, just before driving home with 6mm punch give a little lubrication to head
21. Fit the plate with arrow pointing downwards by hooking into bottom pin
22. Fit top pin, pushing plate back, lubricating before driving home
23. Fit Bridge tube with lubrication
24. Fit Bridge bolt
25. Pump out pistons with brake pedal and ensure they grip and then release with no drag.
26. Best practice is then to bleed brakes to remove contaminated brake fluid from the hose… a cup from each caliper is enough
26.1. Use 14mm six sided socket to slacken bleed nipples
26.2. 10 pumps per bleed nipple
26.3. Wash with water to remove brake fluid
26.4. Dry
26.5. Lubricate bleed nipple and then replace rubber cap.
27. Break in pads.. either 3 fast stops or be nice to them for 100 miles.. racers stomp on them.. car dealers tell you to be nice.
28. With the looser ground pads you will find slow check braking more violent but then you will also find yourself rolling far more easily in queues etc which has to help mpg!

Taking the calipers out and using a vice could be easier.. then you can get a decent hammer blow at it! But then you have brake fluid everywhere and vice marks on the caliper...


Lubricant in my case was Dinotrol 3120 cavity wax to stop corrosion and black moly grease on the threads.

You need pads
Dealer £90 #6LL 698 151
Ferodo Racing DS2500s http://www.europerformance.co.uk/pag...s2500frontpads
GSF ;£60 Mintex Extremes #TTMDB2207X. same as the Clio V6 = http://www.atozmotorspares.co.uk/product_info.php/cPath/1037_28494_28633_28634/products_id/218568

You need fitting kit #6LL698295 (£60 from dealer and is only 4 pins and 2 plates!!!) This has AP reference CP6607-32 inside it but Seat’s part number for AP.

You should get hold of spare bridge bolts =M8x100 capscrews in A2 Stainless steel (4 off) (you need to trim a 100mm capscrew to 92mm if you do not get OEM ones). Threads start at 72mm but you only need them from 78mm from under the head.

You should get hold of spare bridge tubes = 8.1mm ID, 12mm OD and 64.5mm long (I used Stainless hydraulic pipe squared off in a lathe to exactly length). Max OD is 12.3mm.
Consider replacing bleed nipples and rubber caps.

You could modify these calipers to use straight pins and little R clips.. you would need to drill a hole in the pin between the pad and body on the inside.. or there is room on the outside but be careful as the alloys are very close to the caliper.

Notes from previous postings;
>>>>>>>>
disc wise...... size is 312x25x34.5

AP Racing part number is CP6607-31 but you won't find any mention of them on the AP site as they only supply direct to Seat production. Discs are same size as Audi TT, S3, etc so you can get them from most factors for about £30 a disc.

I know that CP 6600 D55 is actually the wrong caliper number, the seat sport ones are based on this design but are really D59. - (no such caliper number) Because Seat sport help develop them, they are 59mm deep instead of a 55mm like the feroddo ones, and they have a unique shape. In the end the guy said "It's only 4mm difference but it's part of the braking system so just go and buy the correct part from the dealer".
<<<<<<<<

.. I have photos of it all... but cannot get to photobucket while awaiting traffic jam clearance .. but if enough want it I will post them..
 

kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
Just be grateful you won't have to do them again for a while lol


Here's some info I got from AP Racing which might help people:

Regarding the pin being stuck / seized in the caliper: - This is an unusual problem; the pins are just a knock in types with a split collets to secure them in the caliper body, hence the need to renew them when fitting new pads for safety reasons. It’s not normally for them to stick in the caliper after service, but try spaying a small amount of WD40 release oil into the holes at the back of the caliper, then leave it over night to soak in. Using a pin punch of no more than 4mm diameter and approx 20mm long; knock out the pins via the 4.2mm diameter holes in the front of the caliper. You can use a reasonable amount of force to do this if you use the correct pin punch!

Any corrosion present can’t be insurmountable because it’s steel into alloy
 

Nath.

The Gentlemans Express
Jan 1, 2006
8,620
16
EASTLEIGH, HAMPSHIRE
As I think I said before, soak the pins with penetrating oil then positive restraint and a very short pin punch just to get it moving and then wallop the punch and hope

A short punch will stop any flexing or bouncing of the punch and may stop blood blisters too :D

Worked for me when I did some

Grinding off the lip is a good tip [B)]
 

CUP-RACING

Active Member
Feb 13, 2007
193
0
I must be the only one who had no problems changing mine then, pins came out pretty easy with a punch.
 

mgrays

Active Member
Dec 9, 2006
371
18
Aberdeen
Hum.. started on long 3.5mm punch.. bent it.. then went to short one.. ended up with it in mole grips.. it broke .. at that point looked in at end of pin and it had bulged over.. lubrication might help tis true.. also being in a vice would help.

I do engineering of pile driving sometimes for a living.. this is 30" to 84" diameter pipe with 1-3" wall. Theory is used to predict how far you can drive these into the ground (typically 300').. and that theory states that there is a limit to the energy you can pass through steel limited by the area and the yield stress of the steel.. i.e. bigger punch = bigger appliable force. Guess 4mm punch plus a good soak might have starting things.. but seeing as it was hard to get the cut part moving I very much doubt it.

Oh this was on sample of one... 32,000 miles, 05 so just on 3rd birthday (MOT Thurs hence pads) .. pads really still have some 15k miles but the lip on the disc makes it look worse and having had one MOT failure many years ago for too little material left.. well better safer than sorry!
 

moodswinger

Guest
Hmmm was going to attempt my fronts this weekend, not sure now, have the pads discs and pin kit, so I guess if the worst comes to the worst I'll end up cutting them out!
 

dozza.13

PS3 Tag - Dozza1979
Jun 30, 2006
1,082
0
Grimsby
Mine needs new front pads, think ill be taking it to my mates garage, this sounds like a potential nghtmare! :(
 

EB20VT

Full Member
Feb 5, 2005
287
0
West Yorkshire
Hmmm was going to attempt my fronts this weekend, not sure now, have the pads discs and pin kit, so I guess if the worst comes to the worst I'll end up cutting them out!

I'd suggest you try yourself, in theory they are really easy to change, 2 pins out, old pads out, new pads on and pins back in. Some of us just got unlucky!!!
 

nealo

Active Member
Oct 12, 2007
88
0
Guisborough
Hi all, I am planning on changing the brakes and pads front and back on my cupra over christmas. My dad will be helping so should be ok. He has told me to ask what the torque settings should be for wheel studs and calipers, both front and back.
Thanks for your help.
 

mgrays

Active Member
Dec 9, 2006
371
18
Aberdeen
Hi all, I am planning on changing the brakes and pads front and back on my cupra over christmas. My dad will be helping so should be ok. He has told me to ask what the torque settings should be for wheel studs and calipers, both front and back.
Thanks for your help.

Humm... tight enough is the right answer;)

.. sounds wrong after we all get taught to use torque wrenches all day long... but when you start to look into what is the correct torque... the fact is that there are too many variables (grease, rust, paint, coatings, thread lock, oil, inaccurate wrenches and wrenchers..) and that the old "feel" has a lot more accuracy as you "feel" the bolts stretch and then you stop. It takes a bit to build up the feel ... but that's experiance for you. Learn to look at a bolt and the material into which it is screwed.. and judge the torque. (i.e. if into Aluminium or plastic.. it takes less torque).

If really worried... then wheel bolts are 80-90 ftlbs (or as tight as you can with the OEM spanner without bursting a blood vessel) and caliper mounting bolts will be similar (probably got thread locking compound on them anyway which knocks all torque measurements sideways:whistle: ).
 

techie

Skoda Techie
Mar 22, 2003
5,438
5
Worcs
IIRC Toms (which was Toms Mums car before hand) was one of the first (first one to be Revo'd thats for sure).
 

Tom B

Active Member
Apr 2, 2002
4,710
16
Northampton
Yeah I'm a bit shocked people had trouble with them, Ross had them off in no time. And he's right, mine's an 04 plate, so one of the first. I used Mintex 1144 pads from the Clio V6 on mine, so they were thicker than the SEAT ones, but there were no problems whatsoever.

AP Racing is a subsidary of Brembo, and I'm pretty confident in saying that they know more than anyone else when it comes to braking. Cheap components will be down to SEAT cost cutting. I'm sure AP would've warned them but SEAT wouldn't see something that seizes in 4 years an issue, when the warranty runs out in 3. Either way, I have no complaints, if they use the same caliper system on TVRs, Nobles, Morgans, etc, they're good enough for my diesel Ibiza.
 

kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
It's just the pins that don't seem to want to come out. AP Racing sent me replacements and they were the same part as the original ones. Maybe the OEM pads give off too much dust or generate too much heat or being 2 part calipers, they warp for some reason (mine don't look completely straight with each other).

The AP Racing calipers are good, my mate uses them on his Westfield but the ones for the Cupra are made specifically for this car so they could have cut costs somehow :shrug:
 

k123

Guest
I had a nightmare with these barakes too....several garages that didn't understand what they were doing, to the point where I found I was missing bridge bolts out of both Calipers!

It took me a while to source the parts but got there eventually so here's the info in case anyone else is stuck:

Bridge bolt = AP Part no CP5555-156ST
Bridge tube = AP Part no CP5200-124

You can't get these from SEAT but the AP dealer network should be able to help.
Questmead (01706 860088 or questmead.co.uk) sorted mine.

£2.25 +VAT for the bolt and £8.72 +VAT for the tube. EACH.
M8 Helicoil kit is only £15 quid off EBAY and dead easy to do yourself.


AP suggested the Helicoil should never come out and you needed to split the caliper to fit a new one but a couple of braincells later and it wasn't that tricky at all.
The point AP were trying to make was that the Helicoil needs to thread from the inside of the caliper outwards so the tang is left on the outside of the thread.

First re-tap the thread into the caliper to get all the road dirt out of the thread. (This can be done from the outside of the caliper)
Then insert the helicoil tool (without the coil on it!) through from the outside of the caliper.
Attach the helicoil to the tool making sure the tang will end up on the outside of the thread and just apply a little pressure to the coil with your finger while turning the tool anti-clockwise and as soon as the thread catches it will pull (Rather than push which is how you should do it) through the thread.
Once you've got all the thread inside the caliper just turn the tool clockwise so the coil locks in place and snaps the tang.

Then follow the rest of this post to lube up the bridge tube and bolt and fix it all in place.


Dead easy. I just hope you're not in the same position as I was in the first place!!
 
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kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
Why did you need to replace the helicoil? I'm thinking about stripping down my calipers and cleaning them as I think I have a sticky piston. I tried cleaning by bridge bolt sleeves but couldn't shift the dirt so may invest in some new ones.

I've just spent the last few hours fitting new calipers to a Westfield and they were alot easier to work with as the pins are held in with spring clips instead of the weird AP design.
 

RUM4MO

Active Member
Jun 4, 2008
7,821
997
South Scotland
Helicoils can be nasty, especially when someone forgets to complete the installation by breaking off the fitting tang, but threaded inserts are essential when dealing with aluminium or magnesium alloys. Bigger and better threaded inserts are available but you need to have enough spare material to let you use them - and of course these bigger better ones will add weight and cost.
 
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