Replacing front discs - Special tools?

P

Paxe

New Member
I´m going to change the front discs on my -73 P63500 but before I go about it I´d like to know if there are any special tools required, or if there´s anything special to keep in mind while dismantling/reassembling? All tips are welcome.
 
Get a good manual "HAYNES" cleanliness is important! good tools 9/16,5/8,11/16,1/2 spanners & sockets,long lever like a crow bar for easing back pistons!! check fluid doesnt overflow under bonnet!!!strong jack,axle stands,you do not have to disconnect the fluid lines,but dont let the calipers hang by them!! tie them up securely.
Basically the proceedure is easy; jack car up and secure well!! remove wheel, brake pads,unbolt caliper and metal-flexi hose mounting point and tie off, undo center wheel hub bearing nut and keep all bits on a clean surface,hub/disc assembly then should come off,seperate the two bits,a vice would be handy here!!and reverse procedure.clean new disc as it has a protective coating,tighten hub nut to torque setting,fit new pads,make sure before you drive it to pump up the brake pedal to re-pressurise the pistons.
take your time with the first one and the second will be easy!!
have fun :p
 
Use a hexagonal shaped socket on the caliper bolts, a normal socket may take the edge of the bolt heads - they are very tight

If you follow the manual you also need a dial gauge to make sure the disk spins true - they can some time waver and this gives you lumpy breaking. If its not spot on you then need to take it all off again and move the disk aroung 90'.

If its still not right send the disks back and get new ones - I'm not convinced garages do this

John
 
Don't forget to make sure hub is perfectly clean before assembly to disc...also do not use grease, needs to be metal to metal. After this offer the disc to the hub, you can usually tell where the best position for the disc lies if u turn it around as mentioned before. Then torque bolts down then assemble back onto stub axle. Before refitting caliper check disc run out using DTI guage. Thats the correct method, but you will probably find that this will not be necessary for guage.
Be carefull not to over tighten wheel bearings, overheating and failure will then occur.
 
As stated by rich j the wheel bearing castellated nut should not be over-tightened. Just nipped up until it touches & the split pin holds it in place.
 
Thanks for the advice, much appreciated. Doesn´t seem to be that hard, then. I'll have a go as soon as the discs arrive.

Cheers
 
A good tip for wheel bearing adjustment that has always served me well is, once its all back together,put the wheel on and do it up well, loosen the castellated nut a bit,if you wiggle the wheel at top/bottom and side/side,you should detect a little bit of movement,tighten the nut up till this "just" dissapears,then,without it showing movement fit split pin as close to that point as you can .
 
The bearing should always have a little bit of play, but it should be as little as possible, so personally I'd tighten up the hubnut to the point where all the free play disappears (you can normally do this with your fingers) then fit the castleated cover to the nut and back off the nut the minimum amount to introduce the free play and fit the splitpin. It's difficult to explain the required amount of play, it just needs that little bit there. Or you can use a DTI and set the free play that way.
I trust you'll be fitting new pads to go with the discs. Also after fitting avoid hard braking first of all to allow the pads to bed into the discs.
 
Could I add one more thing, please pump the brakes before you move anywhere.
Nothing worse than having your foot to the floor and not stopping...
 
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