Handbrake Overhaul

View previous topic View next topic Go down

Handbrake Overhaul

Post by Admin on Fri Jun 07, 2013 4:30 pm

First things first, DO NOT LET PEOPLE TELL YOU THE HANDBRAKE IS USELESS - ITS NOT - THEY JUST HAVE A BADLY ADJUSTED ONE!!  Rant over.....

Anyway, jack up the car and support the car on axle stands or similar.  Remove both rear wheels.




Just for reference here's a pic from the workshop manual so you can see the makeup of components




IMPORTANT *** Dont forget to release the handbrake lever. (the job will be very difficult if you dont!!!!) ***

The handbrake lever tension cable is underneath the car on the driver's side (RHS on UK car as per pic, LHS on US cars).  Combined with release the handbrake lever there should be no tension on the cables now.  Slacken off the first nut which acts as a locking nut then slack off the actual adjusting nut so the cable is loose.  Combiined with the handbrake lever being off the cable should have no tension in it at all.




Remove the pad retaining clip by squeezing the centers together with pliers then pulling the top away from the caliper body.




The pads may well be a tight fit so you may need to use pliers to jiggle/pull the pads out of the caliper body.






Once the pads are removed undo the 2 bolts securing the caliper using a socket and long handled bar.  NB Rather than removing one bolt entirely before doing the other "crack" them both off first before undoing fully.






Secure the caliper to the frame so it's out the way and not straining the brake hose by dangling freely.  Some people use coat hangers etc. but in this instance a tie wrap was used as its a bit more adjustable.  NB There are spacer washers on the inside of the caliper which will most likely drop off when the caliper is unbolted.  Be careful not to lose them so they can be put back when the caliper is re-installed.




Remove the 2 securing pins that hold the brake disc in place then simply pull the disc off towards yourself.



Last edited by Admin on Thu Jun 27, 2013 6:07 pm; edited 16 times in total

Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Admin on Sat Jun 08, 2013 5:50 pm

As well as the shoe mechanism the inside of the shoe will contain quite a bit of brake dust so be careful not to breathe it in.




Brush out any loose dust and inspect the inside of the shoe for damage - again be careful not to inhale any dust.




The shoes and mechanism will likely be covered in dust too so before going any further use a brush to brush out most of the dust (not inhaling of course !)




Each shoe is held in place with a spring loaded locking mecanism which is released by gripping the outer edge with pliers then turning it 90 degrees so the slot in the plate matches the head and unlocks it. Sounds easy but if anythings rusty/very dirty you'll have to fiddle with it a bit. NB there are 2 types of locking pins depending on whether you have an early or late car and to confuse matters further this car was using bolts to fudge it :-(




For reference here are the different types:

The correct ones for my early car




Poor version made one of previous owners - arghhh!!!




The later style (aftermarket)



To take a bit of tension out of the spring if you can rotate the adjuster to bring the shoes closer together




Youll need to remove the spring too NB in the pic the adjuster is missing but in reality spring comes off first then adjuster (think I just forgot to take photo).




With a bit of wriggling the shoes should come away a bit making unhooking of lower spring a bit easier






Last edited by Admin on Sat Jun 08, 2013 11:44 pm; edited 4 times in total

Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Admin on Sat Jun 08, 2013 6:26 pm

You can just about make out the locking plate for the shoes - just use a punch/screwdriver etc and punch it out (assuming you have a new one to replace it with but I strongly recommend you do as they rust and are very cheap to replace)






Why its worth buying new retaining washers etc




Clean the shoe adjuster with brake cleaner then lubricate it with copperslip etc. Run the adjuster up and down the thread a few times to make sure it operates freely












The bottom bracket/lever was a bit rusty so this can be pulled free, cleaned and lubricated then put back




If your intending to buy new shoes measure the width of your existing shoes as there are 2 widths - 25mm on early cars and 30mm on later cars. Mine are 25mm




As with a lot of Ferrari consumable parts rear shoes are very expensive so I opted for some APEC SHU732 brake shoes (25mm width for early cars) which were approx £25 for a set of 4 shoes.





Last edited by Admin on Sun Jun 09, 2013 12:26 am; edited 2 times in total

Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Admin on Sat Jun 08, 2013 11:45 pm

Quick comparison of old and new shoes - in this one all the friction material is gone and the plate is buckled - only fit for the bin :-(




I did indulge myself with a new set of shoe fitting hardware which was approx £70



This is how the shoe locking pegs fit together



Its quite fiddly to put the locking washer round the back of the hub in the hole and for it to stay there so once in place I used a 10mm extension socket which is approx same size to hold it in place. I had actually bought the circlips too which I thought would hold the locking washer in place but they failed miserably so in the end didn't use them.




This is a pic of the locking washer in place after the peg has been pushed through from other side, twisted then locked into its locating channel




Assemble the shoes and adjuster along with the lever at the bottom then whilst holding the locking washer in place at the back using the socket push the pin under the springs tension through the shoe then twist it until you feel it spring into its locking position.

Ready for pushing through shoe



After both shoes have their locking pins secured use pliers to re-hook the springs back in place

All back together with new hardware




One thing which may seem odd is that unlike many cars where the spring has a straight piece in it to go around the adjuster these don't and in effect found the adjuster (something which I think contributes to the "snap" noise whgen release the handbrake). This makes putting the spring back awkward plus also makes adjusting the adjuster very stiff. I actually went to the trouble of ringing Maranello in the Uk and speaking to one of the techs and this is the correct fitting?! If I can find a spring of the same length with a straight piece I'm going to try this one day.



Just one little gotcha to look out for - if you screw the adjuster in all the way it can jam on the edge of the shoe so wind it closed then out again a turn or 2 and then check it still moves once everything is assembled before putting the spring and disk back on.




Line the edge of the shoes up with the protuding edges so they are roughly in the right place (i also found I needed to just chamfer the edges of the shoes with sandpaper just to assist with getting t he drum on





Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Admin on Sat Jun 08, 2013 11:56 pm

Before refitting the drum clean off any rust with abrasive paper




Pay particular attention to the leading edge as sometimes there is a lip of rust which would damage the edge of the shoe




To assist with getting the drums over the shoes get the shoes as central as possible, the adjuster would in as much as you can without the sho edges fouling the cog, any rusty lip ond the drums sanded off and finally sand a slight shamfer on the edge of the shoes. After a bit of jiggling about the drum should slip over the shoes.



Once on screw your locking pins back in.

Now this is the part that will decide whether your handbrake works well or is completely hopeless so take your time. The idea is to get the shoes as close to the surface of the drum as possible without actually touching it (which would drag the car and wear the shoes). To do this you poke a screwdriver through the adjuster hole and turn the adjusting cog to either tighten or expand the adjuster. Not an easy task because of the spring in the way but can be done. Keep adjusting the cog until the drum locks up and cant be turned then turn it the other way just enough so the drum can be turned with the merest hint of a noise of dragging.



Although more time consuming when I thought I had it right I popped a wheel back on with just a couple of bolts as it gives more leverage and a better feel as to whether the wheel is being dragged or not. I also think its more accurate to do this WITHOUT PADS in so you are reading the handbrake force only and not the pads as well.

Repeat process for other side.

Once your satisfied that both sides are adjusted as best as they can be its time to adjust the tensioner underneath the drivers side.

Wind the first nut up until all the slack has gone out the cable then try your handbrake lever. Should only take a couple of clicks to lock the wheel in place so you cant move it. Again this is far more accurate if you have the wheels back on the hubs. If you find that one wheel locks and the other can still be moved adjust either the lockup to be a little looser or the non locking one to be a little tighter via the actual wheels adjuster. It all takes a few reiterations but you will get there! Its worth checking that your handbrake warning light comes on and goes out when the lever is released as well. If it doesn't you have to loosen the handbrake adjusting nuts so that it requires more clicks to switch it on and off.



Once you have them both right tighten up the second nut which acts as a locknut. I feel this assembly is very exposed so have covered mine in grease - doesn't look pretty but helps with weather protection.



You should now have a perfectly working handbrake that will hold the car even on an incline :-) Now you just need to put your calipers, pads and wheels back not forgetting to put the spacers on the inside of the caliper mountings back too (if your stuggling to hold them in place whilst passing the bolt through add a small amount of grease to their surface to make them tacky so they stick in place.

NB Its a good time to replace your pads if required - I used Ferodo FDB451. Pad replacement is covered in another thread in more detail.





Last edited by Admin on Sun Jun 09, 2013 12:36 am; edited 4 times in total

Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Admin on Sun Jun 09, 2013 12:16 am

Just for reference this is what my cable looked like before I started with the handbrake lever pulled right up. As you can see there was still plenty of slack and handbrake was completely hopeless!!!



And a quick video which illustrates why bad adjustment renders the handbrake ineffective - notice ho moving the lever just takes up slack but doesnt pull the cable to apply the shoes.

Double click pic below to play...






Admin
Admin

Posts : 75
Join date : 2013-06-07

View user profile http://www.ferrari348manual.com

Back to top Go down

Re: Handbrake Overhaul

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum