Rear brake maintenance - follow on from 'Safety recall'

[johnatg]

Those of you following the 'Safety Recall' topic will have noticed that 'corroded rear discs' is a recurring theme in the visual safety inspection report. In my own case, they said 'Urgently required - rear calipers seized, discs corroded, pads worn - replacement estimate £530'

So when I got home I checked myself and agreed that the discs and pads needed replacement but there was absolutely nothing wrong with the calipers - sliders were smooth and free and the piston moved in and out easily.

I ordered these:
http://www.ebay.co.uk/itm/310945970419?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.co.uk/itm/EBC-UltiMAX-Rear-Brake-Pads-for-LEXUS-IS250-2-5-2005-/311494286662?hash=item4886819d46:g:mxcAAOSwA4dWNfkY

Total cost £54.64.

Make sure you order the correct discs and pads - these are solid discs - most IS models 2007- use vented rear discs. And 2013- pads are different (and cheaper).

Here's the work:

Remove the wheel, then remove the guide pin retention spring - you can see that peeking out to the right of the outer pad. It locates in holes in the pins.

http://tinyurl.com/ho4bwkn

Now remove the pins - mine were quite well stuck and needed some gentle tapping to extract them, recover the anti-squeal spring and winkle the pads out. They come out fairly easily but you may need to use a screwdriver in their holes to lever them out a little at a time. The inner pad (right) shows the effect of corrosion on the disc - it has worn away the pad on both outer and inner edges

http://tinyurl.com/hwos25n

Now remove the top caliper support pin (/bolt) and rotate the caliper out of the way of the disc. Note that you need to ensure that both the bottom pin and top pin are clean and greased prior to reassembly.

The trickiest part of the whole operation is locating and turning the parking brake adjuster - actually, because this brake is not used when the vehicle is moving (much!) the shoe linings should not be worn and there should be no significant lip on the bell, so you can usually remove the disc without backing off the adjuster. To remove the disc screw a M8 bolt into the threaded holes provided (if it won't just pull off by hand).

http://tinyurl.com/za28lsc

Now clean up the parking brake shoes etc with brake cleaner. You can see the adjuster and how it works. The bottom fork has a pin which turns freely in the body and the top fork is threaded into the body. The adjuster is located at the 3 o'clock position on the left hand side (nearside) and at 9 o'clock on the right (offside). You will need to adjust the parking brake at the end of the job - the adjuster is a bit to the outside of the bell relative to the hole and you turn the notched wheel with a screwdriver towards the front of the car (on both sides - the right hand adjuster has a left hand thread) to expand the shoes and towards the back to contract them.

http://tinyurl.com/zvswmvy

Comparison of the old and new discs - corrosion has set in from both the inner and outer edges of the back face of the old disc. Why this happens is beyond me - you would think that as the inner pad is in contact with the caliper piston, it at least would be pressed against the disc and keep it clean. But it doesn't - and it happens with most cars, that the inner disc face suffers more than the outer. When inspecting brakes you need to remove the pads and take a good look at the inner disc face!

http://tinyurl.com/jdxd5wh

Nothing much wrong with the outer disc face.

http://tinyurl.com/gottv2x

Reassemble with the new discs and pads and adjust the parking brake as above. You screw up the adjuster until the disc is locked, then back off 7 clicks and check the footbrake (/handbrake) operation - it should go down 7-9 clicks) There are two shims on each pad and the inner one should be coated with brake or copper grease on both sides. You should check the run out of the disc with a dial indicator, but I must admit to just doing a visual check that the disc was running true. (I always check front discs with a dial indicator though)

And job's a good'un!

http://tinyurl.com/zw5kx8g

Although I use Redstuff pads on the front, I reckon that Ultimax pads are OK on the rear because the rear brakes don't do much and there's really no danger of fade. They probably will wear more quickly than normal as Redstuff need higher pedal pressures, but Redstuff rear pads are a silly price.

Overall, this is an easy job which should take no more than 30 minutes per side, even with time for cleaning the caliper etc.. It took me quite a while as I took the opportunity to power wash the underside of the car and change the brake fluid as well.

 

Edited June 22, 2016 by johnatg
additional info.

[Cracksta]

Awesome write up! I too had the 'rear brake corrosion' and quoted me something stupid but the rears looks fine and i can do it much cheaper too.

Will definitely be using this guide as a reference when i change the rears in the coming months! :)

[jackcramerr]

To remove the disc, do you need to release the foot brake?

[johnatg]

Yes!

And to turn the wheel when fiddling with the adjuster etc you need the car to be in 'Neutral' rather than 'Park'

[jackcramerr]

why would I need to bother with adjuster ? I am not able to understand how it is working.

[johnatg]

You need to set the brake shoes so that they are very close to, but not touching, the drum, to get the appropriate amount of travel on the parking brake pedal/lever.

As you turn the adjuster the top claw, which engages with the top shoe, winds in or out of the body of the adjuster. Obviously you have to do this with the disc/drum in place so it's a bit like dentistry through a keyhole. You turn the adjuster with a screwdriver against the teeth until the shoes bear hard on the drum at which point you can't turn the adjuster any more and the disc is locked. As the shoes are floating, they centralise themselves in the drum.  Now you back off the adjuster by 7 clicks, or notches on that toothed wheel - it clicks against the spring. Now check that the shoes are not binding on the drum. (This is not that easy as you have to turn the transmission, or at least the diff. as it's connected to the rear wheel, so it is a bit hard to turn the disc anyway. It helps to use a lever against the wheel studs).

Then you check that the pedal travel is 7-9 clicks (on the ratchet). If it isn't, there is further adjustment available at the cable end at the top of the pedal

[johnatg]

I've edited the first post in this topic to add a note about rear discs and to add the step of undoing the top caliper support pin and cleaning and greasing the pins. I think it's complete now!

[jackcramerr]

Thanks. When should one replace the disc? I did not do them when I replaced the pads this year. The pads had atleast 1 year left in them but because I was greasing the pins, I replaced them. 

Visually they look ok. 

[johnatg]

When changing pads, you don't need to replace discs if they are OK - which means thickness greater than 8.5mm (that's for solid - I think yours will be vented and there's a different spec for them), they are not too scored and above all, that there is no corrosion on the faces. In particular, it's easy to miss corrosion on the inner face - unless you take the disc off it's really quite hard to see the whole of the inner face. I hadn't spotted that mine were quite corroded (and both were identical) and I think the MoT tester in November hadn't noticed it either. I am sure they must have been corroded then.

If in doubt, replace! You should replace pads if replacing discs, regardless of wear on the pads.

[Linas.P]

I wonder how corrosion can occur on the faces of the disks? Is that maybe uneven wear on the inner face compared to outer? or is that because rear disks gets used much less than front ones and they are wearing slower than the do corrode? 

[aly-g]

corrosion on the face of the disc would normally mean the caliper slide pins are seized and the pads are not connecting with the discs, i found this out when i first bought my car, so replaced discs ,pads and calipers, no problems since.

 

Allan

[johnatg]

That would explain corrosion on the outer disc face - piston pushes pad into inner face, caliper doesn't slide - hence corrosion on the outer face. But it doesn't explain corrosion on the inner face - the piston should push the pad into the disc and keep that face clean - even if the sliders were stuck. If the piston was sticking, not pushing the pad into the disc nothing would happen and both faces would be corroded. The piston slid in and out easily - compressed inwards with a G clamp and out by gentle brake pedal pressure.

My sliders weren't sticking - the outer disc faces were perfectly clean, but the inner faces were corroded. (Actually probably not badly enough to affect brake force much). And both discs were identically corroded (I only photographed one - you can see it in the link in the first post in the topic)

There's a garage proprietor writes in 'Car Mechanics' every month about interesting jobs in his garage - usually fairly mundane, but interesting nonetheless. It is not uncommon for him to mention a case of inside face disc corrosion.

More theories, please!

[aly-g]

Yes your 100% right John ( I didn't look at the pics before I posted ! ) the rust on the outer edges of the inner disc is strange, I would say the corrosion was present on the disc and the the pads were replaced at some stage with this corrosion in place already . The replacement pads would have worn away to the shape of the rusty discs, what do you think ?

 

The rust on the face of my discs was over the whole face not just the edges which pointed me to seized calliper pins.

 

Allan

[johnatg]

You may well be correct - I changed the pads last time (and it was almost certainly the first change). As the front faces of the discs looked to be in pretty good nick I probably didn't check the inner faces as carefully as I should have.

But it still begs the question - what is the mechanism for clean front faces but corroded back faces?

[RUFFNECK]

Great post fellow member i have a is220d i have had it for a month the brakes are lacking stopping power do you think i should change discs and pads when you buy a car. my discs and calipers look very rusty or brown with brake dust Thinking about getting the parts you stated fellow member.

[aly-g]

Hi Lloyd , welcome to the Loc, don't rush in to buying new discs , pads and calipers, the calipers on my car were seized to the caliper housing very seized !!! After using heat and penetrating oil on the slide pins I managed to free the near side caliper slide pin but the driver side caliper was so seized solid , so I decided to replace both the rear calipers, discs and pads, this job was done curbside out side my house , so what I'm saying is this job is not that difficult .   (Just make sure you have the car properly supported  and chocked at the front wheels) But have look first before you do anything !  Is it brake dust or rust ? The face of the disc should be shiny with no pitting on the face , if any of the discs has pitting on the face then both discs will have to be replaced + new pads . You will have to check the caliper slide pins are free and lubricated . What is the mileage of your car ? Were there any advisory's on the  last mot ?    There is a good service that the dvla are doing now where you can see all the past mot history of your car,if I had had the information from this before I had purchased my car i I would have been warned by the advisory's on two previous mots that the rear brakes should be done , how you can get advisory's two years running for the same thing is beyond  me !  Just one thing more , the brakes on the is2 are not the greatest , so take the wheels off and check the discs, pads and calipers properly before buying any parts. There is a very good post on this forum of how to do this job . If you need any   More help just ask, plenty of people on here have had problems with rear brakes ! ! Let us know how you get on.

Allan

[johnatg]

Spot-on advice from Allan. Only thing I would add is to make sure you check the rear faces of the discs as well as the front faces and check the condition of the rubber boots on the slide pins. At 7 years old they are likely to be quite deteriorated. Be careful when undoing the slide pins/bolts  - if the rubber boots are stuck to them you can destroy the boot as you undo them. Gently unstick the boots if necessary with a bit of manipulation first.

A potential problem you might come across - in my original post I blithely said 'rotate the (rear) caliper to clear the disc'. If the lower pin for the caliper (which goes into a blind hole) is seized, it can be very difficult or impossible to rotate it. There's a good post from jack Cramer a while back on how he freed his up.

And get hold of a workshop manual if you plan to work on the car yourself. They are available on eBay (they come on a CD). That will show you how everything fits together, torque settings for nuts and bolts, etc.

[lexusisfan]

Hi John,

Many thanks for the excellent post, very helpful.

Just got my car back from the safety recall and they have pointed out exactly the same - rear caliper seized (£195 to replace).

Spoke to my mechanic and indeed I've noticed that rear wheel is very hot when I park up and have been told that I should get the caliper pins from the dealer as it looks like the pin is seized. Any ideas if I can get them on eBay or will the dealer have them in stock?

They have also pointed out that I might have to change discs and pads (quoted £295 to replace), whats the feedback on the APEC discs? Any improvements on the braking as I feel the IS250 braking is not the best (compared to the IS300h loan car that stopped like a train!).

 

[ahmedali44]

U better of changing complete calipers , on my is220d front calipers were seized pins were quite expensive, if I'm not mistaken only dealer part, so complete calipers cost me 350 for pair from eBay brand new.not sure how much pins r for rear.check price for pins,then price for complete on eBay 

[johnatg]

It's more likely to be the slider pins than the caliper itself. Your mechanic should be able to free them, but you should certainly replace the pins and rubber boots as well as the discs and pads.

You can't really improve the braking much at the rear - most of the work is done by the front brakes and unless you got into really extreme performance mods you might as well keep the rears standard. The Apec discs are fine - just the same as standard really. And the EBC Ultimax pads.

Dealers would be able to supply pins and boots, but I doubt they'll keep them in stock. (They keep hardly anything except bog standard service stuff.) If you ask a Lexus dealer to do the job, they'll replace the calipers, mounts and everything as a unit. The sliders and boots are all part of that. Best place I know to get brake parts other than on eBay (and I doubt you'll get sliders and boots there) is Brakes International in Rochdale  -  http://www.brakesint.co.uk

They do online stuff and they do pretty much everything you need (including pins and boots - they are officially called bushes.)

Check whether you need solid or vented discs - likely solid, but check!

[steve2006]

Slider pins are around £10.00 each from Lexus.

[RUFFNECK]

Hi john and allen thanks for the advice about the discs,calipers and pads any way cut a long story short i took the car to my mechanic to give it a full service and take the wheels off to look at the brakes. The car has done 135000 not had a service for 2 years when i looked at the service history log book, The car had one owner from new the car is very clean in side and out any way my mechanic rang me today and said the car is ready i said to him how much is the cost of the job he said £120 i was shocked i said no parts he said no theres nothing wrong with brakes discs,calipers and pads ok still in shock paid him the money and drove the car out onto the road to go home the car drives like a dream its running and stopping better than when i took it in to the mechcanic it used to sound like a tractor engine now i cant hear the engine its like my mechcanic waved a magic wand i am still in shock money well spent car drives like new and stops like it should do . Great bit of advice fellow members i love my lexus 220d and the girls love too.

[aly-g]

Glad your all sorted out now, now start enjoying your your new and not that common a car ! 

Allan

[ahmedali44]

On my is220d mechanic did try to free pins but couldn't as were too seized, that when changed calipers.thought about getting new pins but we're working out quite expensive, front ones must b more expensive than rear plus calipers were quite bad, didn't really have brakes.plus it was 1st time in 25yrs had siezed calipers on car like lexus. My black cab tx1 got 400k on clock no siezed calipers. Lexus design is rubbish 

[RUFFNECK]

They make them like that so you have go back to the dealership lexus make more money on parts than they do cars but dont all car makers are the same.