Brake Issue.

JamesIS220 · October 12, 2019

I have a 2006 IS 220D. 186,000miles and over the last week I have braked for an island and the brake pedal goes down halfway and then goes hard/firm. I have to release and full brake power is back and normal operation. It has done this twice. All other times no issues. Any ideas as to the fault? Fluid reservoir full. Air in system? Faulty Master Cylinder?

James.

Barry14UK · October 13, 2019

Hi,

You don't say what work has been done on the braking system and when. If the brake fluid has not been changed in the last 2 to 3 years that would be a good place to start. You may be aware that brake fluid is hygroscopic - it absorbs moisture, so a high level does not exclude this possibility.

johnatg · October 13, 2019

Check the calipers for sticking - either the sliders, which need cleaning and greasing regularly or the caliper pistons.

JamesIS220 · October 13, 2019

15 hours ago, Barry14UK said:

Hi,

You don't say what work has been done on the braking system and when. If the brake fluid has not been changed in the last 2 to 3 years that would be a good place to start. You may be aware that brake fluid is hygroscopic - it absorbs moisture, so a high level does not exclude this possibility.

The brake pads and disks were changed around 3 years ago by the previous owner, but no record of the brake fluid being changed. I'll get it renewed.

7 hours ago, johnatg said:

Check the calipers for sticking - either the sliders, which need cleaning and greasing regularly or the caliper pistons.

I'm going to take it to a garage I trust and get them checked out.

Many thanks. James.

Texas · October 13, 2019

""The brake pads and disks were changed around 3 years ago by the previous owner,""

if this was the last time the calipers were 'worked' on then (as stated above ) the Caliper pins may have well siezed up causing your erratic braking symptoms.

paul m.

is200 Newbie · October 14, 2019

The pins should be cleaned and re-greased at least once a year

JamesIS220 · October 18, 2019

Thanks everyone.

Went in to ATS today and they spent 90 minutes and cleaned the brakes and replaced bleed nipples as blocked and bled new fluid in. The rear nearside did have some air in as went round each caliper. Pads and disks/calipers all good. Said may need to change rear pads as 4.5mm of pad left. Said If I want to supply they'll fit them. Old brake fluid was dirty/old.

They now work much better!

Many thanks. James.

is200 Newbie · October 19, 2019

21 hours ago, JamesIS220 said:

Thanks everyone.

Went in to ATS today and they spent 90 minutes and cleaned the brakes and replaced bleed nipples as blocked and bled new fluid in. The rear nearside did have some air in as went round each caliper. Pads and disks/calipers all good. Said may need to change rear pads as 4.5mm of pad left. Said If I want to supply they'll fit them. Old brake fluid was dirty/old.

They now work much better!

Many thanks. James.

You will find that theres not a lot of meat on the rear pads from new - the braking distribution does not rely on the rear pads like it does on the fronts, Think it is something like 80/20 or something like that. I have just changed my front and rear pads today (inbetween the rain showers - forecast was dry!!) The rears look like they are the ones on the car from new, stamped with Toyota on the backs of them, car is 13 years old although low mileage.

Pins greased on front and back calipers / oil changed / oil filter changed and i scrubbed the wheel arches today - was amazed at how much muck came out of them as they looked clean.Coated all mechanics and rubbers with WD40. Started at 11am and finished at 1:30

is200 Newbie · October 19, 2019

On 10/18/2019 at 7:55 PM, JamesIS220 said:

Thanks everyone.

Went in to ATS today and they spent 90 minutes and cleaned the brakes and replaced bleed nipples as blocked and bled new fluid in. The rear nearside did have some air in as went round each caliper. Pads and disks/calipers all good. Said may need to change rear pads as 4.5mm of pad left. Said If I want to supply they'll fit them. Old brake fluid was dirty/old.

They now work much better!

Many thanks. James.

Dis they take the calipers off when they replaced the bleed nipples?

johnatg · October 20, 2019

You don't need to change the rear brake pads at 4.5mm. Standard rear pads start at 10.5mm and the minimum thickness spec is 1mm (but note that the MoT requires at least 1.5mm). So 4.5mm is about 2/3 worn - plenty of miles to go yet!.

is200 Newbie · October 20, 2019

Agree with John above - more important to stay on top of the front in recognising when they require replacing. That said, i have just been out in mine after replacing all the pads, and along with the re-greased pins, what a difference in the braking - Replaced them all with Mintex pads, I have never gone for the fancy green or red pads etc, just made sure the ones i have used have been a recognised brand.

The brakes are a lot more sharper than before and stop very very well.

JamesIS220 · October 20, 2019

21 hours ago, is200 Newbie said:

Dis they take the calipers off when they replaced the bleed nipples?

Thanks everyone.

Not sure as had to wait in reception. They said they cleaned the brakes by removing pads and pushed the calipers back..

James.

johnatg · October 20, 2019

Hmm... I'm afraid that doesn't sound as if they have cleaned and greased the sliders/pins. You need to find a garage familiar with Lexus brakes.

I can send a drawing of how the sliders are accessed if it would help your negotiations.

It may not be desperately urgent just now but don't leave them too long.

Sent from my PSP7551DUO using Tapatalk

is200 Newbie · October 20, 2019

I doubt ATS would have taken the calipers off - Why do i say this, the time is off (takes someone knowing what they are doing about 15 minutes to do each wheel alone. They didn't know about the pad depth required and the wear factor, the pad depth you have should last with normal breaking at least 2 years possibly more.

I have got to question the pin grease they have used if they are still stating they done it - some of these companies use copper ease or grease which cannot be used for the pins as it will soon degrade due to the heat, clump up and sieze the caliper.

No specialist tools are required to grease the pins - a 14mm and 19mm spanner/socket to remove them. Rubber grease to re grease the pins and bobs your uncle. Would take a garage about an hour to do so would cost an hour or so in labour and cost for grease (no parts are replaced)

If you have the space to do it yourself i would recommend if confident to give it a go, you will soon realise how easy it is to do.

JamesIS220 · October 20, 2019

2 hours ago, johnatg said:

Hmm... I'm afraid that doesn't sound as if they have cleaned and greased the sliders/pins. You need to find a garage familiar with Lexus brakes.

I can send a drawing of how the sliders are accessed if it would help your negotiations.

It may not be desperately urgent just now but don't leave them too long.

Sent from my PSP7551DUO using Tapatalk

That would be great. Pm me or can send my email address.

1 hour ago, is200 Newbie said:

I doubt ATS would have taken the calipers off - Why do i say this, the time is off (takes someone knowing what they are doing about 15 minutes to do each wheel alone. They didn't know about the pad depth required and the wear factor, the pad depth you have should last with normal breaking at least 2 years possibly more.

I have got to question the pin grease they have used if they are still stating they done it - some of these companies use copper ease or grease which cannot be used for the pins as it will soon degrade due to the heat, clump up and sieze the caliper.

No specialist tools are required to grease the pins - a 14mm and 19mm spanner/socket to remove them. Rubber grease to re grease the pins and bobs your uncle. Would take a garage about an hour to do so would cost an hour or so in labour and cost for grease (no parts are replaced)

If you have the space to do it yourself i would recommend if confident to give it a go, you will soon realise how easy it is to do.

I have replaced my Volvo 240 front disks once myself and went well. So will remove and re grease.

Many thanks. James.

johnatg · October 21, 2019

See drawings below.

Front: To remove the caliper from the bracket you only need to remove the small bolt at the very end of the slider. The hexagon on the slide pin itself is to hold the slide pin whilst you undo the small bolt. Take care with the rubber dust boots - if yours are original they will be in a fragile state. They can tear easily if you turn a bolt or pin to which they are stuck - make sure they are free before you turn anything - they are just push fits into grooves. If you need to replace boots you can get them from various sources - Brakes International in Rochdale (mail order or in person) is good. The front ones are a bit of a pain to replace as you need to remove the caliper completely from the car and hold it in a vice whilst you hammer in (with a socket over the rubber part) the metal collar into the caliper. The slide pins themselves just pull out of their holes - but they might need a spanner on the hexagons if they are stuck. Clean and grease the slide pins and reassemble.

Rear: Make a note of how the springs on the pad retaining pins are arranged. Remove the pins and the pads. Remove the top slide pin. Now the caliper should rotate and push off the other pin which fits into a blind hole. This is the one which causes most trouble - it can be hard to rotate the caliper and even harder to push it off if it's seized. Again take care with the rubber boots. Clean and grease the slide pins and reassemble..

is200 Newbie · October 21, 2019

Also check the how to guides on the forum - there are a few instructions of how to strip the caliper down to grease the pins.

normski2 · October 22, 2019

Here is Newbie's guide

I've updated the link in the 'How To' section as well, as that had gone awry.

JamesIS220 · October 23, 2019

That's great everyone, thanks for your info.

I have been doing a few jobs on my 940 as it's in for it's MOT tomorrow so checking it over. Only done cosmetic jobs like clean, underseal, replace tailgate struts, dismantle and clean sunroof switch as opened but wasn't closing! Oil, coolant checks and lights and tyre pressures/ condition.

I'll have a read of the how 2 guide on the pins and do them in around 2-3 weeks as starting a big bathroom gut out and refit next week.

James.