Technical Multipla rear brake tips?

[Magman]

Hi, it's raining, and I don't really want to do it but the rear pads on my Multipla are down to the metal!

Can anyone remind me (it's been a long time...) in a few simple steps what I need to do to fit new discs and pads?

What's the size of the allen key to remove the carrier?
Can I get away with using screwdrivers to wind the pistons back in?
Does the disc just 'tap' off?

I know I'll be ok once I get going, I've done it before...

Cheers

 

[Magman]

Hasn't any Multipla owner on this forum ever replaced the rear discs and pads?

I've borrowed a tool to wind the piston back in, but still can't get it to go back far enough to fit in both new pads!

 

[dave]

it doesn't look like they have but a stilo or other fiat may be the same guides are here https://www.fiatforum.com/guides/

dont forget to take pics of yours and make a multipla guide

 

[BikeDoc]

I really must do my rear pads soon, and sort out the handbrake (one side's mechanism is seized).
I'll take plenty of pics when I do it.

 

[reeseyboy]

I really must do my rear pads soon, and sort out the handbrake (one side's mechanism is seized).
I'll take plenty of pics when I do it.

Seized handbrake cost me a new caliper last year (2009!) Did the pads at the same time, easy-peasy. Be aware that the piston winds in anti-clockwise, not clockwise as stated on here in an earlier post (or they do on my 2002 JTD ELX).

 

[jcc]

Hasn't any Multipla owner on this forum ever replaced the rear discs and pads?

I've borrowed a tool to wind the piston back in, but still can't get it to go back far enough to fit in both new pads!

My Multipla has rear drums not discs? 2004 jtd elx

 

[dave]

there is a 02 reg jtd Multipla on my drive atm, so i popped out to look and that too has drums.
massive drums though

 

[BikeDoc]

Seized handbrake cost me a new caliper last year (2009!) Did the pads at the same time, easy-peasy. Be aware that the piston winds in anti-clockwise, not clockwise as stated on here in an earlier post (or they do on my 2002 JTD ELX).

I'd like to find the guy who designed the rear calipers on the Multipla (and whoever originally came up with the idea for the manual handbrake mechanism on a hydraulic caliper), and kick them repeatedly in the gonads

Took my left one off earlier (caliper, not gonad), and both the lever arm bolt and the spring bracket bolt sheared off, and now they both have sheared stud removers in them as well :bang:
What an absolutely poxy design.

Do both sides wind in anti-clockwise reeseyboy?
The left one does.
I'm sure the ones on my Honda are handed, one ACW one CW...

How much was the caliper? I have a feeling I'll be needing two

Edit; Managed to get one quote already, £171 for both rear calipers (exchange).

 

[BikeDoc]

OK, some pictures...

The two 13mm headed bolts secure the caliper to the carrier, the two 8mm headed Allen bolts secure the carrier to the swing-arm.
There's no need to remove the carrier to replace the pads.
If the sliding mounts in the carrier (where the caliper bolts on) are siezed however, you'll need to remove the carrier to clean and relube them.

r
These are the four stainless plates that the pads bear on, they just pull off for cleaning.
Smear a little brake grease (Copaslip/Neverseize/other) on them after you refit them.
The piston winds back into the caliper anti-clockwise (on the left one, I'll check if the right's the same when I get it off).
You'll need to open the bleed nipple before you wind it back (or undo the brake pipe connection if you're taking the caliper right off).

These are the two bolts that sheared, the left one holds the lever arm onto the splined pivot, the other holds the spring bracket onto the caliper.
I'd recommend leaving them, they will almost certainly shear off if you try to remove them (unless they're fairly recent parts, or they were well protected with something when they were fitted).
If the handbrake mechanism is seized, try freeing it off by soaking with WD40 (or similar) and working it by hand.

 

[Magman]

Brilliant pics, Bikedoc. Thanks.

I think the alley key fittings holding the carrier might be 10mm.

I had another go at mine in the freezing cold in France today, the piston on the nearside (passenger side on my RHD Multipla) caliper seems to have completely seized. It turns through about 90 degrees then comes to an absolute stop. worst of all, the piston's now all the way out so I think the thread's disengauged so I can't even get the old pads back in. Despite the fact they are down to the metal!!!!

On the driver's side, the piston's partially retracted by won't turn in any direction!!!

As far as I am aware, the piston should wind in and out relatively easily?

So I am faced, I think, with ordering two new calipers!!! Ouch!

I'll try GSF in the morning, but reckon postage to France could be pricey. In the meantime, if anyone finds a good source of rear calipers, please let us know!

 

[BikeDoc]

Allparts are my first stop when I need parts.
http://www.allpartsautomotive.co.uk/

Halfords said they couldn't get them
I've also put a couple of requests in to those partfinder sites.
Used ones seem to go for around £30 each (£83-ish for a pair, with VAT+P&P).

I think I may just weld the lever to the pivot, and the bracket to the stub of the sheared bolt.
It won't matter if they're permanently fixed for now.

If the threads of the handbrake mechanism are disengaged, you'll need to push on the piston at the same time as turning it.
I'm fairly certain the right-hand one will need turning clock-wise to reset it.

 

[BikeDoc]

...
I think the alley key fittings holding the carrier might be 10mm...

...the piston on the nearside (passenger side on my RHD Multipla) caliper seems to have completely seized...

On the driver's side, the piston's partially retracted by won't turn in any direction!!!

As far as I am aware, the piston should wind in and out relatively easily?...

Definately 8mm, on mine anyway...

My R/H caliper's piston won't wind back in all the way (it goes in clockwise).
The L/H one went in easily, just turned it with pliers.

The pads in the R/H caliper are only half worn, I doubt it's been working at all, not just the handbrake, as the L/H pads are almost down to the metal.
Don't know how it passed the MOT in Sep, 'cos it's been like it since I got it on 3rd of Oct .
The garage (allegedly) carried out a full service on it, they should have noticed a seized caliper surely?

Anyway, I've ordered a pair of new ones from CAFCO.
I couldn't weld the spring bracket onto what was left of the bolt on the L/H one, not enough 'meat' on it (the snapped easy-out didn't help either).

 

[Magman]

Sorry BikeDoc, 8mm it is!

I've just ordered a pair of calipers from GSF at £67 each plus VAT - they're Delco remakes of the original Bosch I think... with a £40 surcharge.

Too cold to mess about with seized pistons!!!

Mine were unevenly worn, too, so obviously been seized for quite some time. Once they're on just need to sort the slipping clutch and probably also distorted dual mass flywheel. A workshop's quoted £800. Gulp.

 

[BikeDoc]

No need to apologise Magman

I got my replacement calipers yesterday afternoon.
When I ordered them I asked what they would come with (brackets, springs, bleed nipples, etc), so I'd know what to take with me.
They assured me they'd just be bare calipers, so that's all I took down.
You've guessed it, they came complete with all the bits and pieces .
I had to pay the surcharge, but they'll refund that when I take the other bits in.

Took a lot of bleeding, I think the rear lines were completely drained as I didn't plug/blank them off. No problem, I'd rather have fresh fluid in them as I've no idea when it was last done, if ever.

Another bad bit of design is the hose connection to the caliper.
It's just a straight section of rubber pipe, the union screws directly into the caliper body (you have to spin the caliper onto the pipe), and then when you attach the caliper to the carrier the pipe is twisted, it's only approx 4" long, so even an 8th of a turn or so causes it to twist quite badly .
I didn't have time to check if it's possible to untwist it by loosening the other end, where it joins the metal pipe section, they usually have a seperate union nut connector.
It was twisted when I removed it, so whoever fitted it should have sorted it really

I think the R/H handbrake cable is too long, because with the front adjuster set, and the L/H caliper coming on, the R/H one was barely moving, and the balance bar was cocked at about 45°.
There's only the one adjuster, on the handbrake lever at the end of the front cable.
In the end, I machined up a spacer to sit in the bracket on the caliper, to take up the slack.
It works fine now, with the balance bar level and both sides working.

I'll post a couple more pictures later when I'm home.

 

[BikeDoc]

Sorry for the delay, been out playing in the snow (in the Multi' and on sledges )

Caliper carrier fitted with freshly cleaned bearer plates, the tabs (arrowed) go to the outside, i.e. away from the disc. They're handed, four left~four right.

New pads in place. The bearer plates are sprung, so you need to slot one tab of the pad into one of the plates (I found doing the top one first easiest), push against the plate and slip the other tab into the other plate, the tab on the plate helps but you may need to push the plate by hand/screwdriver to get the pad in.

Put some brake grease (usually comes with new pads), or use CopaSlip/Neversieze/Whatever on the piston face and inside faces of the 'legs' of the caliper.
Note the two cutouts on the piston face, they need to be aligned as shown, as there's a 'pip' on the back of the pad (see second pic) that will foul on the piston face if the cutouts aren't aligned.

This shows how the flats on the end of the sliding pins (where the caliper bolts on) need to be aligned, so they don't foul on the edge of the reccess on the caliper mounts. The flats will hit the edge of the reccess to stop the pins revolving as you tighten the caliper mounting bolts.

That should all make sense

 

[SillyBilly]

Hi
I am working on my left hand rear caliper at the moment. Have been retracting the piston anticlockwise using a small stilson. It has gone quite a way back in but there is still 15mm of the cylinder part visible. It is still turning and I have the bleeding nipple loose. Not having seen the internals I am wondering how far it should go. It still turns OK

 

[Zundapp]

It needs to be compressed at the same time as being wound in. You can do this using a G clamp while turning it, or you can get a tool from most auto shops which makes the job much easier.

 

[MrMultipla]

I found this thread useful to replace my worn-out rear pads - thanks everyone.
In case it helps I'm attaching some pictures of what I ended up doing. The driver side (UK) piston was totally stuck and needed a lot of force to rewind (clockwise).
I used a cheap tool off ebay (see pic 'rewind tool') on the end of a pretty big rachet spanner.
In order to secure the caliper so I could push and turn the stuck piston I removed the disc and re-attached the caliper to its standard mounting (see pic 'piston rewound').
Had to stop the caliper halves sliding apart as I leant on the piston. An axle stand taking the weight of the car on the rearmost suspension mount was perfect to wedge a block of wood against the back of the caliper (see pics 'axle stand' and 'wooden block').
Cheers!

Rewind tool:

Piston rewound:

Axle stand:

Wooden block:

 

[SillyBilly]

Helpful pics
Thanks

 

[BikeDoc]

I've just finished doing my rear pads.
I remove the calipers when I do mine, gives me a chance to clean and re-lube everything.

I've often said/written, that if I ever met a modern car designer, I wouldn't get tired of punching them.
Maybe that's too much of a sweeping generalisation.
So.
Whoever thought it would be a good idea to get rid of those simple and reliable opposed piston calipers, and replace them with the sliding type, they deserve a good hard kick in the plums.
Also, linked to that, whoever decided you couldn't have a hydraulically activated/locked handbrake system needs one too.

Next, whoever decided to get rid of Bonnet stays, and just rely on hydraulic struts to keep it open, so that as soon as you get a gust of wind (or a Mouse farts within 10m), the Bonnet slams down and smashes one of the headlights (I kid you not, happened to me today).
They'd get their D*** slammed in said Bonnet.

Then there's the prat who decided to get rid of simple electrical connectors, and replace them with a reconfigured Chinese puzzle.
They'd be dealt with by a trough of water, a Truck battery, and a set of jump-leads.

Rant over...for now.