Replacing MB rear brake pads

NZ XR6 · 21-06-2016, 02:04 PM

I've bought a set of rear pads (Remsa Ultra ceramic) and had a look online for tips on replacing the pads. I'm not planning to replace the discs as they are well above the minimum thickness.

But it seems that it can be something of a mission to get the calliper off, as the piston can't be pushed straight into the calliper and the pads can get stuck on the lip on the outside of the disc.

If you have replaced the rear pads, how much of an issue is this? And can anyone recommend a good tool to retract the piston? I had a Stanley tool, which was OK, but was stolen with my tools when some low life scum burgled our house a couple of years ago.

rondeo · 21-06-2016, 05:52 PM

You need a special tool for the rears. The pistons wind in clockwise. The tool has two 4 or 5mm pins about 32mm apart. I haven't done mine but I have the tool (typical). Not required at front. I just got mine off ebay - caliper wind back tool, clockwise 32mm.

The ridges on the disk edges can be ignored if the disc thickness is OK? Someone?

rondeo · 21-06-2016, 06:26 PM

Looking at the caliper rewind tool I bought it has a reversible disc with 22mm one side and 32mm the other. Must be one or the other because I did the research at the time.

Discs are softer on these? Black dust on mine, but the LX has black steel rims anyway.

My thinking on the disc ridges is they will soon wear the pad and themselves, but my experience is limited.

NZ XR6 · 21-06-2016, 06:51 PM

You're supposed to get the ridge machined off, but I don't bother. Discs are so cheap now it's not worth it.

If the pads do contact either the inside or outside ridges, then I just chamfer the edge of the pad.

Binny · 21-06-2016, 06:54 PM

I had the same issue a couple of weeks ago when I went to replaced the rear rotors and pads.
Finally got the pads over the disk ridges to find I couldn't retract the pistons due to needing a special tool.
I wish I had YouTubed how to do it before I started. There are some good how to vids in there.
I ended up putting it back together how it was.
I have the 105k due in a couple of weeks so I am going to try the mechanic down the road instead of the dealer and I will get them to fit them. I just cbf. I'm too time poor to stuff with it any more.

cobrin · 21-06-2016, 07:24 PM

Quote:

Originally Posted by NZ XR6

But it seems that it can be something of a mission to get the calliper off, as the piston can't be pushed straight into the calliper and the pads can get stuck on the lip on the outside of the disc.

If you have replaced the rear pads, how much of an issue is this?

Decent strong pair of long nose pliers rotate as you lightly push, donski. Wasn't hard nor an issue.

If you did have an issue and weren't able to get the pads out, it's a simple case of removing the caliper from the carrier and bob's your uncle.

NZ XR6 · 21-06-2016, 11:54 PM

OK then, I'll try a pair of pliers first. If that doesn't work, then off to the local Supercheap to buy the Stanley tool.

Some of the stuff on YouTube is a bit dodgy LOL. Watched the Greasy Primate one where he puts a "smear" of copper grease on the edge of the pads and the spring clips. Just when I'd recovered from seeing that, then he puts another "smear" on the back of the outside pad where it contacts the calliper. Not good!

Binny · 22-06-2016, 07:17 AM

I tried the pliers. Couldn't budge it. That's when I decided to put it back together.
I take it that it's that way because of the handbrake?

cobrin · 22-06-2016, 08:19 AM

Oh man....you need the H.B off. It's locked on otherwise.

NZ XR6 · 24-06-2016, 02:22 PM

Quote:

Originally Posted by cobrin

Decent strong pair of long nose pliers rotate as you lightly push, donski. Wasn't hard nor an issue.

If you did have an issue and weren't able to get the pads out, it's a simple case of removing the caliper from the carrier and bob's your uncle.

I tried to change the pads on one of the brakes, but the long nose pliers weren't up to it and started to twist. It was quite difficult to remove the calliper, but that was nothing to do with the ridge on the disc. The calliper was a snug fit over the pads, and there are serrations on the piston which had gripped the rubberised backing plate. There's a bit less rubber there now ...

The pads still have 3-4 mm left, so no rush to change them - I'll probably wait until the service is due after winter. I was interested to see that the OE pads are Galfer, which I associate with motorcycle brakes. But it seems that they are actually a Spanish company.

cobrin · 24-06-2016, 04:44 PM

I used a cheap pair of JBS long nose pliers (kept my good tools aside if they needed) to test and it did it first go. H.Brake cable was removed, it was as it should be.

NZ XR6 · 24-06-2016, 06:31 PM

Quote:

Originally Posted by cobrin

I used a cheap pair of JBS long nose pliers (kept my good tools aside if they needed) to test and it did it first go. H.Brake cable was removed, it was as it should be.

I removed the handbrake cable (that was fun!), although I'm not sure that it's necessary and it isn't in the Ford manual. The piston wasn't going to move without some serious force, so I put the old pads back and left it for another day.

The pads had worn very evenly and the outer had worn more than the inner.

Binny · 24-06-2016, 07:31 PM

Yes I removed the HB too.

cobrin · 24-06-2016, 11:45 PM

I was doing the rotors as well, may have been the Haynes manual suggested it.

rondeo · 25-06-2016, 10:11 AM

This is the windback tool I bought. Looks the same as the Ford special tool and good quality:

http://www.ebay.com.au/itm/Ford-Mond...K6kZ-sHNJB6YPg

Binny · 25-06-2016, 04:52 PM

This is the first vid I found when I looked it up and he describes it all well.
Even says you can do it with decent pliers but the tool is better.
https://www.youtube.com/watch?v=8MA41pqREEE

rondeo · 25-06-2016, 08:43 PM

The video gives you an idea what's involved. I'd consider a bit less or no copper grease (I thought he used too much, attracts dust and risks spreading to the disk) clean and lube the guide pins and remove old threadlock residue from mounting bolts.

rondeo · 25-06-2016, 08:56 PM

Quote:

Originally Posted by NZ XR6

I removed the handbrake cable (that was fun!), although I'm not sure that it's necessary and it isn't in the Ford manual. The piston wasn't going to move without some serious force, so I put the old pads back and left it for another day.

The pads had worn very evenly and the outer had worn more than the inner.

Maybe the MB has RH thread one side and LH thread the other, I have a vague memory of something along those lines from when I bought my RH windback tool for the MC. Just a hunch.

NZ XR6 · 25-06-2016, 11:35 PM

Quote:

Originally Posted by rondeo

Maybe the MB has RH thread one side and LH thread the other, I have a vague memory of something along those lines from when I bought my RH windback tool for the MC. Just a hunch.

I don't think so, you'd need 2 different wind back tools.

I agree about not using grease - never put it on brakes unless the manual says to do so.

cobrin · 26-06-2016, 01:32 AM

It spins me out that he never noticed that there wasn't any grease on the whole lot and parts not supplied with grease, so then thinks that you should use some....ludicrous!

always dry unless it's designed with grease, to which I've not come across ever......(not saying there can't be in some weird situation or weather)

rondeo · 17-08-2016, 05:49 PM

I'm about to replace front and rear pads and rotors on my MC.
I watched the greasy primate video on You Tube, handy for rehearsal but:

''CAUTION: Make sure that the mating faces are clean and free of foreign material and that no grease is applied to the brake pad guides."

Is from the Ford manual, just to confirm what has been discussed previously.

The outer rear pads were showing 3mm but the inners were beginning to score the disc. Front discs down to 26mm which is the wear limit. Not bad for 148000 km on original pads and rotors.
Will grease the slide pins only I guess.

bundybear75 · 17-08-2016, 07:55 PM

Quote:

Originally Posted by rondeo

I'm about to replace front and rear pads and rotors on my MC.
I watched the greasy primate video on You Tube, handy for rehearsal but:

''CAUTION: Make sure that the mating faces are clean and free of foreign material and that no grease is applied to the brake pad guides."

Is from the Ford manual, just to confirm what has been discussed previously.

The outer rear pads were showing 3mm but the inners were beginning to score the disc. Front discs down to 26mm which is the wear limit. Not bad for 148000 km on original pads and rotors.
Will grease the slide pins only I guess.

Uneven wearing like that is a sure sign of the slide pins sticking.

Happened to me about 12 months ago on my Commodore, noticed the uneven wear on one side, though I must do something about that, and then promptly forgot about it until the horrible grinding sound commenced.

New pads and a little grease on the slide pins and all good.

rondeo · 21-08-2016, 07:58 AM

I have the rear brake caliper mounting brackets on the bench at the moment and the guide pins appear to be in very good working order. They slide easily and the grease appears clean.

This leaves me wondering why the inboard pads have worn 27% faster than the outboard pads.

If the caliper piston were not retracting (slightly) wouldn't wear be equal on both pads?

Or were the pads were sticking in the guide shims? But they look OK. Anyway - both pads wearing on the inboard only, and by exactly the same amount?

I noticed when inspecting the guides that if I pushed the pin inward air was expelled from the boot which then held the pin in by a partial vacuum, because the air pressure only increases the sealing effectiveness. On the other hand if the pin is pulled outward there is a force acting to push the pin inward which would result in a small constant push of the inboard pad onto the disc, because it is trapped between the caliper piston and the disc.

This led to the idea that the grease inside the guide would act as a seal to prevent movement of air around the pin, resulting in even stronger forces, one of which is in the same direction required to press the pad to the disc . . . but only if the guide was packed fully with grease, which it wasn't.

So in conclusion: Unresolved. The brakes have been great up to now though.

This little animation shows the action of a single piston sliding caliper:

https://www.youtube.com/watch?v=ar5j1mUdFA8

The guide pins on the Mondeo are different though, effectively reversed with the pin sliding into a hole blocked at one end.

This one is more for entertainment:

https://www.youtube.com/watch?v=YJmDNJn0WW0

cobrin · 21-08-2016, 01:37 PM

Inner pad wear is typically the piston in that it's not returning to the retracted stop position, often due to a worn seal or damaged or corrosion. It can also be caused by a problem with the master cylinder, I've not yet come across one that was.

If the piston were at fault you'd see the inboard pad typically wear more and evenly.

Is the wear across the inboard pad even or tapered?

Tapered can suggest seized at/during some stages on one side the guide pins, but as you say they're free floating well then check out your shims for any binding/restrictive movement for the pads in situ. I wouldn't worry about the boot as long as it's not perished. You're using the proper silicon grease for brakes yeah?

and lets not forget the rears also have the Handbrake that could also be the reason either through use or wear/adjustment. When I did my pads I also adjusted the H.brake cable down the rear/mid end and needed to re-route (re-tie) one of the cables as it could be seen from outside- under the vehicle, didn't seem right was all.

hope it helps.

rondeo · 21-08-2016, 03:58 PM

Thanks Cobrin. I didn't look at the piston, seemed easy enough to move, I have CRC Brake caliper grease but didn't use it because the original grease looked fine. Now installed the brakes and pedal work fine.

I made a few notes for next time, any improvements or corrections appreciated:

DIY RENEW MC BRAKE PADS AND ROTORS.

Apply the handbrake and remove the T50 disc securing screw.
Release the handrake.
With 10" adjustable spanner wind the handbrake spring back and remove the cable nipple from the lever.
Remove the cable with long nose pliers by squeezing the tabs on the plastic retaining ring and pulling on the cable (easier said than done, and the tabs are easily trashed, being very flimsy).

Remove the slide pin retaining bolt with a 13mm spanner.
Use a 15mm spanner to prevent the slide pin turning.

Remove the caliper and support it somewhere out of the way. Remove the pads.

Use an 18" bar and 15mm socket to loosen the caliper mounting bracket bolts and then remove.

Remove the disc.

Temporarily install the mounting bracket and caliper with lightly tightened bolts.

Make provision for dealing with the brake fluid as discussed below.

Wind the piston back to the stop with a clockwise rewind tool and close the bleed screw. The plate on my rewind tool needed shortening to 75mm to fit inside the caliper.

Remove the caliper and support it out of the way by resting it somewhere. Remove the caliper mounting bracket.

Instal the disc.

Instal the mounting bracket, pads and caliper, having cleaned everything and lubed the guide pins ONLY.

NOTES

I fiound it easier to wind back the piston when it was installed in its usual place, ie bolted to the caliper bracket.

Brake fluid:

The concern may be that particles might enter the ABS system.

A few ways to do this:

a) Clamp the brake hose closed and open the bleed screw with a tube to a container.

b) Apply pressure with a pressure bleeding device and open the bleed screw with a tube to a container. Caution: Do not exceed 14 psi, as per Ford manual.

c) Just loosen the bleed screw to a tube and container.

I don't like clamping the hose for three reasons: the hose is stressed, debris could delaminate fron the inside and if the bleed screw is open the fluid isn't going very far up the brake line. I use a pressure system.

cobrin · 21-08-2016, 07:23 PM

One omission I noticed:

As these are top hat rotors don't forget to wire buff/brush clean both hub and mating surface on the rotor (hub, rotor side and wheel side), it's always forgotten and important to keep clean. Otherwise you can introduce or allow a slight misalignment causing vibrations/drag/pulsations....simply put undesirable affects.

rondeo · 22-08-2016, 09:13 AM

A few things I missed:

DIY MC REAR BRAKE PADS AND ROTORS. 1st revision.

Apply the handbrake and remove the T50 disc securing screw.
Release the handbrake.
With 10" adjustable spanner wind the handbrake spring back and remove the cable nipple from the lever.
Remove the cable with long nose pliers by squeezing the tabs on the plastic retaining ring and pulling on the cable (easier said than done, and the tabs are easily trashed, being very flimsy).

Remove the slide pin retaining bolt with a 13mm spanner.
Use a 15mm spanner to prevent the slide pin turning.

Remove the caliper and support it somewhere out of the way, not dangling from the hose. Remove the pads.

Use an 18" bar and 15mm socket to loosen the caliper mounting bracket bolts and then remove.
Remove the old guide shims, noting any difference between them.

Remove the disc and clean the hub with a brass wire brush.

Temporarily install the mounting bracket and caliper.

Make provision for dealing with the brake fluid as discussed below.

Wind the piston back to the stop with a clockwise rewind tool and close the bleed screw. The plate on my rewind tool needed shortening to 75mm to fit throught the caliper bracket.

Remove the caliper and support it out of the way by resting it as above.
Remove the caliper mounting bracket.
Remove clean and lubricate the guide pins with brake grease if required. (The Ford manual cautions against applying grease to any other component).

Instal the disc (T50 screw).
Instal new guide shims into the mounting bracket and instal the bracket (bolts 110 Nm) pads, caliper (bolts 35 Nm) and handbrake cable, having cleaned everything.

Press the brake pedal a few times to settle the pads.

Test, don't forget the road wheels (nuts 140 Nm).

NOTES

I found it easier to wind back the piston when it was installed in its usual place, ie bolted to the caliper bracket.

Although torque figures are given for the caliper mounting bracket bolts, my torque wrench and socket didn't fit in the confined space.

Brake fluid:

The concern is that particles might enter the ABS system.

A few ways to do this:

a) Clamp the brake hose closed and open the bleed screw with a tube to a container.

b) Apply pressure with a pressure bleeding device and open the bleed screw with a tube to a container. Caution: Do not exceed 14 psi, as per Ford manual.

c) Just loosen the bleed screw to a tube and container.

NZ XR6 · 23-08-2016, 12:45 AM

Thanks for the write-up. With regards clamping the brake hose, the fluid will follow the path of least resistance. I'd suggest opening the nipple a couple of turns and using tubing with a decent ID.

Sent from somewhere using Tapatalk

rondeo · 23-08-2016, 05:02 PM

Quote:

Originally Posted by NZ XR6

Thanks for the write-up. With regards clamping the brake hose, the fluid will follow the path of least resistance. I'd suggest opening the nipple a couple of turns and using tubing with a decent ID.

Sent from somewhere using Tapatalk

I think the same.

Finding it too hard to pull the handbrake cable through its mounting bracket I used a locking plier on the cable ferrule and levered it out with a screwdriver while squeezing the plastic retainer with long nose pliers. Since the ferrule is plastic there's a risk of cracking it so best to clamp only as much as needed and use a bit of cardboard or leather in the jaws ...

bundybear75 · 01-09-2019, 01:31 PM

Once again, I've brought my excavator out and dug up an old thread....

When winding the piston back, is it a lot of turns? I have turned mine heaps and it doesn't appear to be retracting. Do I have to crack open the bleed screw?

Im stuck at the moment, old pads out but cannot get the caliper over the new pads....