2007 RX 400h SE Brake disc thickness and Rear wiper assembly

TomSaintJames · November 25, 2023

Morning Lexus folk, I have two questions that I'd like to ask:

1. Minimum rear brake disc thickness, I've been reading online for the past hour and have seen many different numbers posted - 6.5/8/8.5mm. Does anyone know where I can find the correct thickness for my car? I think the discs on the car are the originals, it had just over 100k miles when we bought it a few years ago and were over 150k now, I replaced the fronts (and pads) when we bought it. Funnily enough, when kwik-fit put some tyres on earlier this year they tried to sell me rear brakes - dream on boys.

2. Rear wiper assembly. This was seized, lubricating made no difference so I removed it and because the nut and metal washers were seized either side of the glass, I only went and broke the glass... I was being so gentle as well! A new windscreen later and I now need to source these inner and outer washers with their rubber gaskets.

It took me 20 minutes of gentle persuasion just to get the wiper arm off the splines!

I can find a part number for the outer metal washer (85169R) and the nut (85168R) but not the inner washer. The complete assembly is obviously now off the car, but I cannot undo the nut without further knackering the apparently quite soft metal - below is how it came off the car. What I think happened is the whole washer assembly was turning as I was trying to undo the nut, the locating tab at the rear hit the wiper motor housing, pushed it out and broke the glass. It did go bang!

I'd appreciate your thoughts, I'm yet to contact Lexus themselves for the rear screen parts but will do so.

ColinBarber · November 25, 2023

3 hours ago, TomSaintJames said:

1. Minimum rear brake disc thickness, I've been reading online for the past hour and have seen many different numbers posted - 6.5/8/8.5mm. Does anyone know where I can find the correct thickness for my car?

Minimum thickness is 8.5mm. If they are original discs then that figure will be stamped on them somewhere.

INSPECT DISC THICKNESS

Using a micrometer, measure the disc thickness.

Minimum thickness:

8.5 mm (0.335 in.)

Standard thickness:

10.0 mm (0.394 in.)

If the disc thickness is less than the minimum, replace the front disc.

TomSaintJames · November 26, 2023

Thanks for an excellent reply Colin 👍

ColinBarber · November 26, 2023

On 11/25/2023 at 6:46 AM, TomSaintJames said:

I can find a part number for the outer metal washer (85169R) and the nut (85168R) but not the inner washer. The complete assembly is obviously now off the car, but I cannot undo the nut without further knackering the apparently quite soft metal - below is how it came off the car. What I think happened is the whole washer assembly was turning as I was trying to undo the nut, the locating tab at the rear hit the wiper motor housing, pushed it out and broke the glass. It did go bang!

Unfortunately I believe the part you are looking for comes as part of the motor assembly and isn’t available on its own. If you purchase a secondhand motor, make sure it includes that part.

Also make sure you use the full part code, not just the category code. E.g. 90099-05157 for the nut.

85110R	MOTOR ASSY, REAR WIPER
85130-48030		1	€ 218.83
85132A	COVER, REAR WIPER SHAFT
85132-53010		1	€ 4.66
85168R	NUT, REAR WIPER LINK PIVOT, NO.1
90099-05157		1	€ 5.26
85169R	WASHER, REAR WIPER LINK PIVOT, NO.1
85134-53010		1	€ 6.56
85178R	NUT (FOR REAR WIPER ARM SETTING)
90179-06158		1	€ 1.20
85190R	ARM ASSY, REAR WIPER
85241-48040		1	€ 44.76
85192R	COVER, REAR WIPER ARM
85292-28030		1	€ 4.59
85214R	RUBBER, REAR WIPER
85214-30280		1	€ 11.51
85220R	BLADE ASSY, REAR WIPER
85242-48030		1	€ 12.81