Rear brake pad change - issue retracting calliper

Dracoro · June 19, 2016

Changed brake pads a few times over e years (not this car though, 07 Lexus GS300) but i can't see how to extend out the calliper. Managed to compress in the piston OK but could not retract the calliper so effectively could only put new pad on one side of disc, the pther side I could inly put in the worn pad, too small a gap to put in new pad. Handbrake off, undid bleed nipple, top off fluid reservoir but could not retract back calliper.

Any ideas? For. Kw I have put old pads all back on to tackle another day (or pay someone )

is200 Newbie · June 19, 2016

I believe the calliper is the same as the IS models (someone can confirm if this is correct ?)

The calliper is held on by a bolt and a fixed slide pin. Undo the bolt at the top of the calliper, drop the calliper down and slide it from the fixed slide pin. If the calliper wont drop down then you have a seized calliper which I expect is the case.

Verbout · June 19, 2016

If they are the same as the IS250 sounds like you have a seized sliding pin.

Plenty of WD40, or equivalent, and a large rubber hammer.

Have a look in the "Brake and Suspension" section of the GS forum, lots of advice.

Dracoro · June 19, 2016

There are two pins that hold the pads in. They came out OK once the retaining springs removed.

the top bolt undos, but the bottom one was stiff (but cannot unbolt it as it's just a hinge) and cannot "slide it" it in/out.

the rear callipers were mew from Lexus about 3 years (27k miles) ago. Would they sieze in that time?

where would I spray WD40?

Verbout · June 19, 2016

On the part that seized, the sliding pin.

I would respectfully suggest you give the job to someone who knows what they're doing, you shouldn't be messing with brakes if you don't know what you're doing.

is200 Newbie · June 19, 2016

Sounds like you have seized calipers - ideally they need greasing up every year (I do mine every 6 months) .

They can be released / eased free if not too far gone by a bit of patience / WD40 / GENTLE tapping from hammer over a piece of wood or other medium (not direct on the caliper itself) - if they can then give them a very good clean and grease. They should be a service item but for some reason Lexus has elected not to include them on the schedule. Last done 3 years ago, sounds like they are seized especially when you cant drop them out of the way. If one has gone then its likely the other will need doing - also consider the fronts. Its not a hard job - 1 hour should see you complete all 4 corners if no issues arise.

is200 Newbie · June 19, 2016

2 minutes ago, Verbout said:

On the part that seized, the sliding pin.

I would respectfully suggest you give the job to someone who knows what they're doing, you shouldn't be messing with brakes if you don't know what you're doing.

As with Garry on this one - but ensure all 4 are checked out.

Dracoro · June 19, 2016

Done pads/discs many times on variuos cars, however not had callipers siezing before.

if I can free the slider pin, does one grease with copper grease or normal?

Verbout · June 19, 2016

I prefer silicone grease, but have used copper grease. Some will say buy super duper Lexus/Toyota grease because "I want to keep it original"

Whatever you use its a good idea to check, clean and grease regularly.

is200 Newbie · June 19, 2016

Owners will use different greases (what they are used to) - just make sure its suitable for its intended use. I use Toyota rubber grease which greases the pins and does not attack the rubber components allowing dirt to get in, used it for years with no issue. Comes in a large toothpaste sized tube for around a tenner.. Don't use normal grease, it needs to be a hi temp grade.

Verbout · June 19, 2016

Due to this being a common issue has anybody thought of taking off, or has taken off, the calliper carrier and having it bored out a little so there is more play and therefore hold a decent amount of grease?

is200 Newbie · June 30, 2016

On ‎19‎/‎06‎/‎2016 at 10:51 PM, Verbout said:

Due to this being a common issue has anybody thought of taking off, or has taken off, the calliper carrier and having it bored out a little so there is more play and therefore hold a decent amount of grease?

The pin recess on mine are quite deep and it collects a wod of grease right at the end of travel for the pin - when I clean them out there's always a lot at the end that needs to come out - with the rubber grease I put on, it goes on clean in a pink colour and when cleaning after 6 months it comes off in a slightly faded pink colour. Does its job well with no worn rubber boots on the calipers (yet !)

Verbout · June 30, 2016

I'm going to have a look at mine, when I can be bothered, I did them six months ago but like to keep a check on them.

The first time I did them they took some moving with WD40 and a rubber hammer.

Boddney · October 30, 2016

I think I'll do mine next week and take pictures a and pop it in the 'how to' section .

Edit...... No I won't bother doing the 'how to' as it's already been brilliantly done by Tigerfish in the GS (1993-2004) section.

Edited October 30, 2016 by Boddney
Incorrect information

Verbout · October 30, 2016

Checked all mine a few weeks ago...silky smooth still

Britprius · October 30, 2016

A grove ground along the slide pins preferably in a spiral path, but straight is ok will hold more grease and allow it to travel along the pins more readily from the blind hole end of the caliper. This works better than increasing the clearance, and avoids the rattle cause by to much clearance.

John.

true blue · October 30, 2016

Hi this is a very common problem as discussed ,I have recently greased mine ,which I do regularly with ' Locktite ' super lube synthetic grease ,I have been using this for years on many different calipers and it gives excellent results .I would not advise using copper grease as this attacks the rubber bellows .I wonder if part of the problem is caused by careless replacement of the rubber bellows in the machined grooves in the castings .You have to be very careful that the rubbers are fitted properly using a torch to see all the way around ,if there is one small area where the bellows is not in a groove water will soon enter ,and by capillary action wash out your grease to allow seizure in a very short time .

Verbout · October 30, 2016

I don't hold with the "Copper grease/slip causes damage to rubber" I believe it's just a mantra that everybody chants on forums.

Its use is not as a grease, it's an anti-seize, and isn't "rubber" on cars composite silicone?

true blue · October 30, 2016

Hi ,Verbout ,I can assure you I don,t chant mantras on a technical question , I am a trained engineer ,time served in the aircraft industry and having worked many years in the automotive industry ; we were taught by the suppliers of some of these compounds ;- antiseize grease is NOT a lubricant ,it is designed to dry out and leave a base which will not allow parts to bind together , eg threaded fasteners ,close fitting assemblies , if you look at one of the manufacturers specification https://james walker.biz/products /88 it states not to be used on natural rubber ;butyl;or ethylene propylene compounds . I know various manufacturers will use different petroleum type carriers in their grease ,but this is not the correct solution when correct alternatives are readily available

Dave

Verbout · October 30, 2016

11 hours ago, true blue said:

Hi ,Verbout ,I can assure you I don,t chant mantras on a technical question , I am a trained engineer ,time served in the aircraft industry and having worked many years in the automotive industry ; we were taught by the suppliers of some of these compounds ;- antiseize grease is NOT a lubricant ,it is designed to dry out and leave a base which will not allow parts to bind together , eg threaded fasteners ,close fitting assemblies , it states not to be used on natural rubber ;butyl;or ethylene propylene compounds . I know various manufacturers will use different petroleum type carriers in their grease ,but this is not the correct solution when correct alternatives are readily available

Dave

Hi Dave,

I am a trained engineer ,time served....So am I. :)

Antiseize grease is NOT a lubricant......I believe I said that. :)

If you look at one of the manufacturers specification https://james walker.biz/products /88....corrected that for you :)....https://www.jameswalker.biz/products/88

The reasons I don't particularly believe that copper slip causes damage to modern car "rubber" components is they are not made of rubber.

Another reason is, in my experience, I cannot recall replacing a "rubber" component on a car that has come into contact with copper slip and therefore been damaged by it. I also cannot call replacing a "rubber" component on a car that has perished due to coming into contact with the obvious petroleum products that are on our road, either in the make up of the surface or products spilt on the roads. All this is continually thrown up at our car while we drive.

And finally, aren't the gaiters on the driveshafts, on the steering racks and the connection to the petrol tank feed all made of "rubber". They are all in constant contact with petroleum based products that they keep in place, they seem to survive.

I believe the only time I have replaced these "rubber" components is due to mechanical damage.

I could go on, her indoors says I do