Brake Calliper sticking again, time for GS brake upgrade?

[McShmoopy]

HI Guys

Just noticed today that my rear driver side calliper was kicking out alot of heat and a smell so the calliper has likely seized up again. Usually I tend to grease these yearly but I figured bad weather has sped this up although the rear driver side calliper has always been more problematic. I noticed a few old threads on here mentioning how alot of guys upgrade to the GS brake callipers and its a noticeable improvement not only brake wise but it also prevents alot of excessive brake pad wear and maintenance.

I was wondering if I sourced GS MK3 brake callipers for the rear is it worth doing the front at the same time, and will I need a whole set of new pads and discs when I swap them over? 

[J Henderson]

44 minutes ago, McShmoopy said:

I was wondering if I sourced GS MK3 brake callipers for the rear is it worth doing the front at the same time, and will I need a whole set of new pads and discs when I swap them over? 

The rear brakes on a GS are exactly the same as what you already have on a 2010 IS250, so that wouldn't be an upgrade.

As for needing new discs and pads. You might get away with cleaning the disc up, but new pads will probably be needed. Usually, when a caliper has been sticking, one of the pads gets heavily worn down compared to the other.

[McShmoopy]

30 minutes ago, J Henderson said:

The rear brakes on a GS are exactly the same as what you already have on a 2010 IS250, so that wouldn't be an upgrade.

As for needing new discs and pads. You might get away with cleaning the disc up, but new pads will probably be needed. Usually, when a caliper has been sticking, one of the pads gets heavily worn down compared to the other.

Interesting I read up that plenty the MK3 GS’s had the same brakes that the IS350 is rocking and is a significant upgrade? 

 

[ColinBarber]

16 minutes ago, McShmoopy said:

Interesting I read up that plenty the MK3 GS’s had the same brakes that the IS350 is rocking and is a significant upgrade? 

Yes on the front. The calliper is a 4 pot design, with 2 on each side which is unlike your single piston sliding calliper design that requires sliding pins that seize up. But the rears are all the sliding calliper design so will suffer the same issue if you don't do regular maintenance on them.

[J Henderson]

Sure, the fronts are definitely an upgrade.

4 piston monobloc AVICS calipers & 334mm discs vs single piston caliper/carrier setup (slide pins) & 296mm disc.

But the rear brakes are the same on IS250/IS350/GS300 - 310mm vented.

You mentioned sourcing GS calipers for the rear, hence why I said you already have those.

"GS brakes" on the rear would only be an upgrade on an early car with solid discs.

Edit: beaten by Colin 🙂

[McShmoopy]

28 minutes ago, ColinBarber said:

Yes on the front. The calliper is a 4 pot design, with 2 on each side which is unlike your single piston sliding calliper design that requires sliding pins that seize up. But the rears are all the sliding calliper design so will suffer the same issue if you don't do regular maintenance on them.

23 minutes ago, J Henderson said:

Sure, the fronts are definitely an upgrade.

4 piston monobloc AVICS calipers & 334mm discs vs single piston caliper/carrier setup (slide pins) & 296mm disc.

But the rear brakes are the same on IS250/IS350/GS300 - 310mm vented.

You mentioned sourcing GS calipers for the rear, hence why I said you already have those.

"GS brakes" on the rear would only be an upgrade on an early car with solid discs.

Edit: beaten by Colin 🙂

Ah that makes a whole lot of sense to be fair, cheers for clarifying guys, is the majority of braking done by the front brakes or the rear for rear wheel drive cars then? I do have new discs and pads for my front brakes that I haven't got around to doing yet so wondering if its even worth the upgrade for the front...

[ColinBarber]

29 minutes ago, McShmoopy said:

is the majority of braking done by the front brakes or the rear for rear wheel drive cars then?

The front, about 70% on a RWD car, and even more on a FWD car.

[Mihanicos]

Use silicon grease on the slide pin.

[McShmoopy]

1 hour ago, Mihanicos said:

Use silicon grease on the slide pin.

That’s usually my go to grease although I might try replacing the rubber gaskets for the slider pin as they seem like they’ve seen better days 

[Mr Vlad]

Hi Bilal. Instead of re-greasing the slider pins just get brand new ones. Also wrap some sandpaper around a screwdriver shaft, grit around 240, to clean the holes where the sliders go.

I had a quick look yesterday for aftermarket opposed calipers for the is250. Nothing came up but except from America and costing £3.5k but one British firm makes them from billets and at about £240 but they're not is250 specific. Perhaps look online and enquire to firms you find. 

HEL Performance was the firm I found. Look them up. Who knows you may strike lucky or they'd make them special if you mentioned there would be hundreds of fellow is250 owners would want them too.

[McShmoopy]

On 2/16/2024 at 12:42 PM, Mr Vlad said:

Hi Bilal. Instead of re-greasing the slider pins just get brand new ones. Also wrap some sandpaper around a screwdriver shaft, grit around 240, to clean the holes where the sliders go.

I had a quick look yesterday for aftermarket opposed calipers for the is250. Nothing came up but except from America and costing £3.5k but one British firm makes them from billets and at about £240 but they're not is250 specific. Perhaps look online and enquire to firms you find. 

HEL Performance was the firm I found. Look them up. Who knows you may strike lucky or they'd make them special if you mentioned there would be hundreds of fellow is250 owners would want them too.

Thanks for the suggestion Vlad, I took your suggestion and ended up getting new slide pins, funnily enough they give you the bind bolt also but its a little odd seeing as you cant ordinarily get it out.

I neglected to realise that the new rubber seals have to go over the slide bolt calliper lips and if they dont youll just end up seizing the calliper as it cant physically go all the way. 

This video from Bing a known Lexus 2IS enthusiast / model has an excellent video detailing how to remove and replace the slide pins and gaskets which isnt always obvious so I'd highly recommend it. 

A handy temperature gun after a brisk drive around showed both left and right rear brake discs were only heating up to 49oC compared to when the calliper was seized was 130oC! I considered changing out the left also but if it isnt broke dont fix it haha, I still may consider the GS front brake upgrade if I can score them at a decent price but I'll use these spare discs and pads for my mums IS250 worst case.