Changing rear brake pads guide

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Hi

Great "How to thread", but I have run into a problem!!

After completing the procedure as per instructions - I pumped the brake pedal but found that the pressure is dropping once the car is started?? It is fine when engine not started.

Is this a sign of needing to bleed the system or a master cylinder issue?

Just for the record - no bleed nipples cracked open and no brake fluid overflowed and the brake fluid level is fine??

Confused.com!:confused: Cheers C

Generally speaking that sounds as per normal, maybe you have never tried pumping the pedal with the engine "off" then started it - if that is all it is then what you are experiencing is the servo doing its job, plus a bit of you needing to wait until the new pads have bedded in.
 

enigma

Active Member
Feb 9, 2007
109
0
Thanks for the guide came in very useful for doing my discs and pads, lessons learnt that might be useful for others attempting this:

1. Buy an impact driver before you start , saves a lot of swearing at the disc retaining screw/ rounding it out , tbh its not coming off with a normal wrench.

2. The caliper tool is worthwhile , however the pistons winding back in takes longer than you would think.

3. A hammer is also really useful for removing the old disc and pads.

4. Buy a can of WD40 before starting , as everything behind the wheel seems to be rusted like mad.

:D
 
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philje123

Chug chug
Jul 5, 2011
152
0
York
Hey guys.

I used this giude and the information in this thread to do my front discs and pads today.

It really is straight forward to do.

You will need a decent socket or spanner set. I recommend ones that push on the flats of the nuts (i.e. it looks like a star rather than just the 5 flat sides) as this will avoid rounding off those annoying stubborn nuts! I used a decent quality ratchet set from halfords (half price) and they came straight off by exerting some force with my foot.

I used a G-clamp to push the calipers back in as I found it a bit hard with just my hand.

Gave everything a good old scrub with a wire brush and used plenty of copper grease and all friction surfaces and on the back of the pads.

I'd say in total, including nipping to the parts shop on my bike for a G-clamp and a couple of sidelight bulbs, it took me about 2 hours. I did also have to shelter inside for 10 mins as it absolutely persisted it down with rain!

Sorry I didn't get any pictures but just needed to get it done as we're possibly going up to Masham tonight then Bridlington on Sunday.

Phil
 

krussel

Active Member
Oct 31, 2008
1,713
2
Hertforshire
Thanks for this guide and posts. Iam planning to strip mine down to re-paint the calpiers and will tackle the rusting rear discs as well before the mot. Folllowing the advice Ive ordered a impact screwdriver/ wrench :D

As i wont be changing the pads yet do you think i will able to get away with not winding back the calpiers ? :confused:
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Philje123, I don't want to cause an upset, but using "bi-hex" ring spanners is usually okay, but if you really want to avoid rounding off nuts or bolt heads then you should really use quality hex ring spanners and sockets - the bi-hex feature is only there to make fitting the head easier from an angle side of things. If you are meaning these "fit all damage all" metricinch spanners, then yes they do bite and they also damage the heads. Remember "hex" = 6 not 5 and STAR is usually only used for TORX type heads. One other thing, you say that you retracted the rear pistons only using a G-clamp, that was not too good as there is a thread in there that means that they need wound in while pressing them back in - you will now have either damaged them or not got them back in far enough.

Trouble is, all these tools tend to have a "lead in" at the start of the openings - to make using them easier - but when the bolt heads are "short" like on these mounting bolts which have a built in washer, then a bit of extra care is needed to avoid slipping off the head - same thing with sockets etc, which is why some people end up machining these "lead in" off and have a second set which stay as they were.
 
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RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Thanks for this guide and posts. Iam planning to strip mine down to re-paint the calpiers and will tackle the rusting rear discs as well before the mot. Folllowing the advice Ive ordered a impact screwdriver/ wrench :D

As i wont be changing the pads yet do you think i will able to get away with not winding back the calpiers ? :confused:

I bought in stainless steel screws and fitted them when the car was only 4 yaers old - to avoid any future problems - but getting the screws out was not too difficult - maybe put a spot of copperease on the screws before refitting them.

As far as not needing to retract the pistons to do what you want to do to the rear discs, yes as you are not replacing the discs with thicker(new) ones or pads that are not thicker(new) you should get away with it - but don't mess about with the handbrake or foot brake while the brakes are in bits. You might find that you will benefit from retracting both sides though as that will correct any issues that the car has with the handbrake levers not returning fully - so consider borowing or buying a tool from maybe Halfords.
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Thanks for the guide came in very useful for doing my discs and pads, lessons learnt that might be useful for others attempting this:

1. Buy an impact driver before you start , saves a lot of swearing at the disc retaining screw/ rounding it out , tbh its not coming off with a normal wrench.

2. The caliper tool is worthwhile , however the pistons winding back in takes longer than you would think.

3. A hammer is also really useful for removing the old disc and pads.

4. Buy a can of WD40 before starting , as everything behind the wheel seems to be rusted like mad.

:D

Re "3)" big screwdrivers used as levers are good!

Re "4)" try something stronger than WD40, start off with something that will not harm anything in that area, like brake cleaner used with a small stiff brush - ie loosen up and wsh away the dirt and brake dust, then only use stronger penetrating/release products - I'd be surprised if you end up needing the stronger stuff, just work away with the brake cleaner and stiff brush. WD40 is nothing more than light weight crap with caster oil in it to chase away water and create a short term water resistant layer - but it does have its uses elsewhere.
 

philje123

Chug chug
Jul 5, 2011
152
0
York
Philje123, One other thing, you say that you retracted the rear pistons only using a G-clamp, that was not too good as there is a thread in there that means that they need wound in while pressing them back in - you will now have either damaged them or not got them back in far enough.

Nah. The front calipers don't need winding in. They simply just push back in.

It's just the rears that need winding back in.

Phil
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Nah. The front calipers don't need winding in. They simply just push back in.

It's just the rears that need winding back in. Phil

Yup, but this thread is about changing the rears, but now I've seen that you were answering about changing the fronts, even though, given the subject of this thread, your advice could have been taken as "being okay, (in general) just to use a G-clamp" when it is not. By the way, if you use a thinnish block of wood and just reverse the wind-back tool's adaptor, you end up with something that will make life a bit easier when pushing the front pistons back in, kind of doubles the use you can get out of this tool.
 

philje123

Chug chug
Jul 5, 2011
152
0
York
Yeh sorry for causing any confusion!

What I should have said is that although this guide is for the rears it came it handy for the fronts as they are very similar!

Just ordered some new discs and pads for the rear.

Phil
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Thanks for the great guide, did new disks and pads all around today and this guide was useful. Only had a problem with the fronts trying to find a 7mm allen key, none of my kits had one! Cheers

Ha, you need to get a "man's" set of hex keys, I seem to remember needing to buy an individual 7mm allen key way back in my early Ford Escort days - but later I tended to buy proper sets of allen keys AND later a big set of hex/spline/torx/rib when I had more money!!
 
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spideymack

Active Member
Oct 24, 2008
17
0
Central Scotland
Can anyone remember what size and type the bolts that hold on the carriers are?

I'm in the middle of changing rear discs and pads (stopped now cos it's dark). Got the calipers off fine, so the carriers are next. Was getting dark but had a quick feel with a 7mm hex key and it feels too loose. Is it an 8mm?
 

spideymack

Active Member
Oct 24, 2008
17
0
Central Scotland
Update it is an 8mm hex for the carriers, but turns out you don't need to remove the carriers to replace the discs. It is tight but they just squeeze in without too much of a scrape.

Annoying thing is someone previously has replaced one of the slide pins with one thats too big and had jammed solid! When I eventually got it out you can see that it is bigger than the others! New one arriving tomorrow, so immobile till then.
 
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