Does anyone have a step by step procedure in replacing the rotors on a 1991 348? I know there is one posted for brake replacement. How about exploded view of brakes and rotors. Do you need to remove both caliper bolts? What it the torque on the caliper bolts? I will be installing new brakes and resurfacing the rotors in the next four week. Thank you for this form it has helped me many time in fixing my 348.
For the caliper bolts the torque is 64/Nm (6.4/Kgm). For the bolts holding the rotors in place use 20/Nm (2Kgm). Keep it simple. Remove the wheel. Remove the caliper. Remove the bolts that hold the caliper in place and then move the caliper out of the way (you should use a coat hanger to hang the caliper so you don't mess up the break lines), and you may need to hit it with a soft hammer to get it to come loose. Now unbolt the rotor retaining bolts and remove the rotor. Resurface or exchange with new rotors and then replace the rotors then the calipers. http://www.the348.com/tech/348.html#Brakes http://www.the348.com/tech/348.html#cvjoint Image Unavailable, Please Login Image Unavailable, Please Login
I found this post when I started thinking about replacing my rotors on my 93 348. One thing that is on my 93 (not sure about the 91) is there is a hardline now for the brake line feeding into the caliper. You have to remove that to get the calipers off. I took that out carefully, then capped it with a speed bleeder cap (I'm installing speed bleeders all around) as a temp stop for the fluid. The first one took me about 1 hour to get everything undone, out and replaced. I took the whole thing off and pulled the pads and pushed the pistons while I had it off the car. the 2nd side took me about 30-40 minutes. Other than having to beat the crap out of the rotor on the LF to get it off. I also used my piston tool while the caliper was still on the call... WENT much faster. See pic. The caliper bolts are 19mm. The bleeder screws are 11mm or 7/16. Image Unavailable, Please Login
I did a writeup on overhauling the handbrake which involved removing the rear disks - see link below. BTW if replacing rear rotors replace the shoes at the same time plus obviously replace pads whether front or back. Handbrake Overhaul As mentioned you need to undo the hard pipes on the fronts - right old pain - have a look at my experience on my 348 - I ended up making new hard pipes etc 348 DIY "Restoration" - Page 132
A quick question... my front rotors weren't held on with anything other than the wheel studs. There are 2 holes for screws. .. just missing. Daniel says they should be held on with a wheel nut but these are just slip on rotors Mobilized reply by Dahveedem
Yes they should, however if you have fitted wheel spacers you may (not always) have to remove them so they dont foul http://www.eurospares.co.uk/partTable.asp?M=1&Mo=434&A=1&B=23677&S=
Hmm... no spacers..I have to bleed them so I'll take pic on Wednesday of the setup. Mobilized reply by Dahveedem
Just a few tips from when I changed my rotors. There is no need to disconnect any of the hydraulic pipes from the calipers. The front is tricky, but the hard pipe connects to he flexible pipe on a bracket that is bolted to the hub back plate. There are two very small nuts holding it onto the back plate. They are fiddly but its much easier that having to bleed the braking system. When you take the calipers off the hubs, carefully check how ,many shim washers there are on ALL the bolts. Again, they are fiddly to get back in on reassembly. Best to stick them together with a spot of glue before sliding them in and pushing the caliper bolt through. All in all a piece of cake except you will need a sledge hammer to dislodge at least one of the disks off the hubs!!!!!!!!!!!!!!!!!! If you decide to change the handbrake shoes, be very careful about disconnecting the hand brake lever from the cable. It can be the most frustrating bit on the whole car to get it back on! You have been warned. Patience is a great virtue! Good luck.................
I was planning on bleeding anyhow. .. Not sure it's been done. But thanks for tip. Re the shims - let's say you don't put them back in same setup (in case someone else reads this thread). How could performance be affected or show up as issue. I had 3 extra on the LH side. .. Mobilized reply by Dahveedem
Pic of the nuts clive is referring too - mine were well rusted :-( Also, I padded the rotor with a lump of wood before hitting it from th eback with a lump hammer - it was extremely tight NB note the pins dave was on about on the disk Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
hmm... I bet those pins are removed on mine because i'm running 360 wheels on the car. I'll grab some shots of the back side of mine when I bleed her on Wednesday. Any tips for which end to start? do I open both pistons at once per caliper? Never done a 2 piston caliper before. I have speed bleeders all around so that will make it slightly easier. Gonna bleed the clutch line in the mix too... Thanks.
360 wheels fit with pins - I have 360 wheels as well as 355 wheels. Use a pad spreader as per pic above but rather than have it all one one side of the disc put it both sides of the rotor so all the pistons can be spread at once. Both ends have their foibles - rear involves doing handbrake, front involves fiddling with hard pipe etc. Personal preference is rear but thats just me! LOL
Those shims are there to centralise the calliper on the rotor. The tolerance in the 355 manual (I would expect 348 to be similar) is for the calliper to be parallel within 0.3mm or 0.118 inch. I fitted new callipers all round last year. Bought a selection of shims of different thickness's per the parts manual and spent a few hours (or was that all day) getting within tolerance.
I had tried that.. but doing it that way only caused the inboard piston(s) to compress. got to the point I couldn't turn the thing anymore.. so I thought what the heck.. I'll just move it to the other side of the rotor and that worked. it was kinda frustrating honestly.
Is that a limitation of the tool or did the pistons seem stiff? BTW If your doing it one side at a time leave the pads in the other side so they dont pop back
Don't have to open both bleeders at the same time. Do the outboard one first then the inner one and you will be good to go. Porsche uses the same calipers and I have been doing it like this for years without any problems. Just make sure you have all the air bubbles out before moving to another bleeder. This is one of those "feel good jobs" when you are done.
So bled system tonight. Brakes went very smooth. Speed bleeders made it very easy. Clutch. .. had a pucker moment when it went fully to the floor and didn't come back. Luckily my buddy brought his power bleeder. Hooked it up, took it to 10 psi per instructions and bled her out. Clutch feels firmer than before and now my system is full of a nice blue blood. Took for drive, bedded in the rotors and she's ready to roll for a couple drives this weekend. Not sure why clutch bleed didn't work without power. Mobilized reply by Dahveedem
