Britprius

Your battery I would say will be in the average range as the longest period of inactivity is only three days. John.

Yes this is generally the accepted formula. Many disability batteries are rated to 100% discharge. If you have a battery of 45 AH a 70% discharge would be 31.5 AH of usable capacity. If you have a battery of 60 AH a 70% discharge would be 42 AH of usable capacity an increase of 25%. I use a mobility battery in my GS450H rated at 110 AH instead of the OEM 70 AH. John.

This is so, but only when the car is in ready mode. In all other modes the high voltage battery is completely isolated from the rest of the car. John.

Well Matt this is not as simple a question as it may sound, but I will keep it as brief as I can. All lead acid batteries have one thing in common. They do not like to be stood partially charged. In this state the plates of the battery are prone to sulphation " a hard white lead/sulphur compound that if left cannot easily be turned back into acid no matter what some charger manufacturers say". This compound acts as an insulator, and also reduces the strength of the acid. If a hybrid is used every day for a reasonable length of time the 12 volt battery will always be at or close to fully charged so no reason to trickle charge it. If the car is used only once a week then trickle charging while the car is idle would be beneficial because the car discharges the battery while standing, and the battery has some self discharge. If the car is used even less frequently I would say it is essential to trickle charge if you want a reasonable battery life. The 12 volt batteries that Toyota/Lexus use in the hybrids are AGM batteries "absorbed glass mat". This means there is no free liquid acid in the battery as in the case of ordinary normal car batteries "flooded lead acid". So there is much less acid available, and is reduced in strength quicker when sulphation takes place thus reducing the available capacity more quickly with AGM. AGM batteries tend to have a greater amp hour capacity for a given physical size, and have a slightly higher output voltage of circa 14.2 volts against the flooded battery of 13.8 volts. It is important therefore that the charger used is suitable for AGM batteries as some flooded battery chargers do not put out enough voltage to fully charge AGM batteries. The Toyota batteries are known for not recovering well from being deeply discharged. If you want a battery with a higher amp hour capacity of the same physical size to the OEM the batteries used in disability scooters not only have much higher capacity, but are much more ruggedly built, and designed to be deep discharged on a regular basis with little or no damage. The only downside is that they do not have standard battery terminals. The Toyota 45 amp hour battery can be replaced with a battery of between 55, and 60 amp hours. for the same dimensions. John.

I would think you are talking about the servo vacuum non return valve. If so this should be available as separate part. John.

Replacing a reluctor ring is within the realms of the average DIY requiring removing the drive shaft nut, and wheel hub to expose the drive shaft end, and reluctor ring. If the old ring is cracked it will just pull off with your fingers. It is then a matter of cleaning the drive shaft surface and tapping on squarely the new reluctor ring. If the new ring is not very tight on the shaft apply some bearing fit to the mating surfaces. Bearing fit is is a compound that as it dries expands. Ebay is the place to get the rings. Check the inside diameter, and the number of teeth for correct fit. John

As others have said this looks like an acid leak from some time ago. It may be the first owner had carried a split battery in the rear of the car or had a battery fall over spilling acid. This would take considerable time to show up as damage, and could and most likely is continuing to take place. Treatment with an alkali would be advised as soon as possible to stop this spreading further. Another step to take is to check the date stamp on the existing battery to see if this has been replaced possibly due to damage or a problem with the old battery. If the battery has been changed this may well be on Lexus service records for the car. John

Well done. Do you find the exhaust as quiet as the OEM or do you get a bit of a drone under acceleration? Also the burning question if you do not mind telling us. What price did you pay, and how much was replaced? John.

It is not imperative that you use tagged batteries, but it is desirable as the tags can be soldered to the connections in the monitors.You can just fit the replacement cell in the monitor and rely on the surface contact as the electrical current draw is minimal. Another alternative is to use the conductive glue to connect standard cell in the monitors. This is listed in the link below. http://www.smallbattery.company.org.uk/sbc_tagged_lithium_coincell_catalogue.htm John.

Check the condition or the propshaft joints possibly the most likely cause. John.

The speedo in most cars over reads the actual speed, and this is allowed for in law. A speedo may reed over by a given maximum formula, but may not under read. This is to stop people saying they were sticking to the speed limit according to there speedo, and therefore were not deliberately speeding. I doubt very much anything will be done to correct your cars reading as this is done electronically from the ABS wheel speed sensors, and is not adjustable. John.

Unfortunately HPI will not always show up a damaged vehicle. It will only show where there has been a insurance claim. There are many situations where this is not the case. You will find many salvage yards advertising damaged cars as "not recorded". John.

It is perhaps a little ironic that the hybrid battery in the RX is very different to the rest of the Toyota range. The RX battery is arranged as 3 packs with 3 cooling fans, and the modules are steel cased instead of plastic having 8 cells per module at 9.6 volts against 6 cells 7.2 volts for the plastic variety . This will mean unfortunately that the RX modules will be much harder to obtain than there plastic counterparts. Picture below. John.

Have a look at the US Prius Chat forum. This is something that can be done for a few pounds as it only require the column switch and a new stop lamp switch. The CT is based on the Prius using the same running gear. John.

There is one for sale on Ebay with front end damage still drive-able for £4795. This would repair for less money, and you would have full knowledge of what the damage was. John

Leigh. Try Ebay item number 332285774538 this is a pack of 4 for £8. There will be parts you do not need, and they are labeled for BMW, but this makes no difference. Alternatively you can use item number. 252719828473 at £5 for one, and these are listed as Mazda. John.

Not sure what you mean about voice control button. The tyres are standard tyres but the valves in the rims are not the standard rubber type. Externally they are aluminium, and internally they have a battery operated pressure sensor with transmitter. A receiver in the car picks up this signal to give low pressure warning. The sensors are £40 each upwards, and are replaced when the batteries go flat. You can replace the batteries for very little money. Do a search on TPMS battery replacement. John

If you can find anyone to refurb the shocks that would be a good option as long as there is not to much rust near the bottom of the shocks that I have already mentioned. In my opinion it is the poorly designed or virtual none existence of dirt contamination protection of the seal area that is the basic cause of the failures. I have managed to refill, and reseal the shocks, but found the seals were difficult to get hold of, and required new caps to be machined to hold the seals. The reason the shocks are so expensive is that they are adjustable. The adjustment being driven by a servo motor mounted on the top of the shocks. You could fit the shocks off the same year non hybrid GS300. These are virtually the same, but are not adjustable, but at £150 for the pair in your situation could be a viable alternative. Leave the servo motors in the top housing not mechanically connected to the shocks held in some sponge to stop them rattling. This would stop any fault codes appearing. John.

Yes the shocks are £250 each, and I could have made that clearer. Good luck with with the used parts, and I hope they prove me wrong, but the warning was genuine if you go back through the many 450H posts on this subject. John.

Hi Lee. There is no option for aftermarket shocks for the GS450H. I cannot see any reason why left and right hand drive shocks should be any different. If you are considering using used parts I would strongly advise against this as the GS450H shocks are prone to leaking at even low millage's at the shaft seal. Anything over 80,000 miles is doing rely well there have been reports here of shocks failing at 20,000 miles. So you could be going through the exercise again within a short period. Also be wary of rust between the lower body of the shock and the ABS cable support bracket. A common failure point according to the Lexus dealers. There is a place in Birmingham that is selling genuine shocks at around £250 if you need details let me know, and I will dig them out. Fitting is easy with no special tools or spring compressor. I can fit fronts in less than 1 hour per side. Again if you need details just ask. John.

It is a misconception that higher rated fuel means more mpg. It is the number of calories in fuel that decides it's energy content. The so called lower grades of fuel contain more calories, and as such used in an engine designed for that fuel will give the best mpg. Diesel is a lower grade of fuel than petrol, but gives better mpg. Higher rated fuels will only give there best when used in engines designed to use them. You get no benefit from using a high rated fuel in an engine not specifically designed for it. John

It can be done at home with little mechanical knowledge. Do a search on cleaning EGR valve. I should have said the means "exhaust gas re circulation" John.

www.gov.uk/getting-an-mot/after-the-test According to the above you can drive your vehicle away to have work done providing it is not dangerous. John

It could be the EGR valve is blocked, and needs cleaning a common problem with diesels used for short journeys. John.

Yes. If the cover is missing the is a possibility of a metal object placed in the boot shorting out the battery giving rise to a fire. John.