GS300h2014

Explanation of the complexity of working on hybrid brakes:

https://www.toyotaownersclub.com/forums/topic/198134-hybrid-pad-disc-replacement/

Changing the pads/discs on a Toyota/Lexus hybrid is only slightly more complex than for conventional setup. I found it best to disconnect the 12v Battery before starting. I suggest you review some of the youtube guides before you start in order to avoid problems specific to hybrid brakes.

My wife & I spent 5 days in Cadiz in late May several years ago. The jacamuda trees were in flower & a terrific sight. We loved our stay. I  recommend you visit Le Caleta beach used in 007's Die another day film. Great for coastal walks.

I had the same problem on my 2011 Toyota Auris. It was caused by a poor connection in the under-seat plug & socket. This is a not uncommon fault as the under-seat cables get moved whenever you adjust the seat.

Before doing anything more complex as Chris suggests try a quick & simple remedy. After waiting 2 minutes after having the car powered down, disconnect the under-seat connector & spray it with WD-40 Contact Cleaner (not the ordinary WD-40). If you are uncertain if the fault relates to the driver's or passenger's seat do both. This permanently solved my problem & hopefully will do the same for you.

In case you haven't seen this report dated February 2023. 'Which' has 3 categories: 0-4 years, 5-9 years and 10-15 years. Details include Lexus scoring 5 stars in all categories. Next were Toyota & Honda with 4 stars in each category. BMW, Mercedes, Vauxhall, Ford, Nissan & Peugeot all scored an average 3 stars in each category. Porsche was 2/3/na, Tesla was 2/1/na & Land Rover was 2/1/2 respectively. Alpha Romeo was bottom with 1 star in all three.

The report says that these ratings includes each brand's electric, petrol & diesel cars. However Mercedes EVs trumped all other brands & fuel types whereas Audi EVs scored 1 out of 5 stars. Presumably these EV ratings apply only for 0-4 year old cars.

My understanding is the coolant changes are only specified by Lexus & Toyota in miles covered & not time duration, but I'm happy to be corrected. So 100k & 150k miles for engine & the inverter respectively.  I guess this would make sense if it only degrades when it's hot. This would also explain why the inverter coolant has a longer life as I presume it gets less hot.

I wonder how Lexus tests the coolant; do you think they check to see if it's turned acidic?

Relax, you're fine. It's not the date that's important but whether your petrol car is compliant with Euro 4 emission standards. As the system show's your car is ... then end of story.

In my experience the major problem is caused by grease previously applied hardening over time due to heat from braking. The only effective solution is to ream out the hardened grease in the sliding pin hole and to use a tub of silicon grease for lubrication and rust resistance. This is highly temperature resistant,doesn't harden nor causes damage to any rubber or plastic such as the boot covering the sliding pin.

My suggestion would be to get the two rear tyres off the ground using axles stands or a centrally placed jack & try turning the wheels by hand to find out what is binding. Try doing this after pressing the brake pedal down.  If the brake master cylinder or a brake load proportioning valve is binding then the continuing high pressure will not allow the pads to retract causing the symptoms you describe.

It may reassure you know that the Mk4 GS is not inherently unstable. My 2014 GS300h with AVS feels totally planted on the road at speed. It feels very safe & stable at high speed, more so than any other car I've driven. It's behaved like that since new and has now done 67k. Presumably you've had the front hub bearings checked for play?

Your Toyota & Lexus tyres have the same diameter of 17" but your Toyota tyres are lower profile (45 vs 50) so you would expect the Lexus to have a superior ride. One can only assume its down to the tyres, what tyres have you got on both cars? My 2014 Gs300h with 18" tyres is better than my 2011 Auris even though the Auris has smaller rims with a much higher profile tyre. I suspect the heavier Lexus helps reduce the impact of bumps in the road. I've got all weather tyres on both cars.

I would think the procedure is the same for a RX450 as for my GS300h. No need to bleed the brakes or remove relays. Make sure the electric handbrake is disengaged & the driver's door is open then disconnect the Battery. Wait 5 minutes then pump the brake pedal 40 times to ensure the brake system is depressurised then proceed as normal. However when finished, press the brake pedal hard to reposition the new pads before reconnecting the Battery. You might need a syringe to remove excess brake fluid from the reservoir.

Chris,

By sound connections, I meant check the cables are firmly attached to the Battery posts. Check by just trying to rotate or move them by hand. Regarding the 12 volts, you don't want to be at 0% on this chart i.e. circa 10.5 volts.

I would expect your Battery is a wet type.

First off I would check your connections at the Battery are sound. Second I would use a multimeter to check your Battery voltage is circa 12 volts & if ok check you've got voltage at your fuse boxes. If you haven't got a multimeter, you can buy one for £9 from Screwfix.

My thoughts are only to use caustic soda or sulphuric acid on semi blocked pipes (just like Piers did). The logic being that if it doesn't clear a totally blocked pipe and you have to use mechanical means to clear it; then you're going to be dealing with some very unfriendly liquid in the way.

I would add a note of caution regarding diy on a hybrid's brakes. You will need to do your homework as the hybrid's brakes use an electric hydraulic pump which needs to be disabled by disconnecting the 12V Battery (as the pump can operate even when not in the 'ready' mode). However that shouldn't stop you working on them as the dealers are often neglectful e.g. regarding lubrication or freeing up of the floating brake calliper pins.

How old is your fob Battery? 

They look pretty hefty cables, do they connect to the starter motor or the Battery? I wonder if the joint's function is a cable connector rather than an earthing point. Is this a 'if it ain't broke don't fix it situation'? Have you any problems or symptoms with your car? 

How very odd behaviour in a 27k miles 5 year old car. Could it be fuel contamination?

I'd start by checking the state of charge your 12v Battery with a multimeter.

Isn't this addressed by Zotto's post above; option is for year of production (1508 means August 2015)

My 2014 GS300h Premier provides alternative routes. You can setup the 'detour' options by going to MENU (on the map screen) then 'Route' on the navigation menu screen then select 'Detour'. You then have various options  i.e. 'Around traffic event' & 'Whole route' (to calculate an entire new route to the destination.

Suggest you try replacing the expansion tank cap as it might have a weakened release valve.

If the Battery is in the boot it's likely to be an AGM type. Rather than spending 140 euros on the dealer, I would suggest you use a multi-meter to check the Battery charge as and when the problem re-occurs. These hybrids only recharge the Battery at circa 5A so it does take a fair bit of time driving to re-charge the Battery.

Be aware WD40 is not the best rusted bolt fluid to use in my opinion. In fact Car Mechanics did a comparison test published here:

http://www.bilthamber.com/downloads/penetrating-oils-2.pdf

Results gave GT85 (8 out of 14 for performance), Plus Gas Formula A (8/14) Bilt Hamber Ferrosol (8/14) but WD40 (5/14)

'Obviously we couldn’t do a penetrating oils test without having this household name in the group. But, somewhat predictably, WD-40 cannot quite cut it against the dedicated automotive brews. Part of the reason for this is the very reason that WD-40 has become such a big-selling product: its incredible versatility. Just reading the tin identifies diverse applications like polishing brushed metal surfaces, preventing slugs from climbing plant pots, and even cleaning crayons 
off washable surfaces. Another great bonus of the product is the simple fact that practically everywhere sells it. And, in all reality, compared to our fully dry ‘test control’ bolt, WD-40 did reduce the loosening torque and it certainly made it easier to spin the bolt out – just not anywhere near as effectively as other products here.