Parking brake adjustment 2007 GS 450h MK3

[Manee]

Evening all,

Sorry if it has been covered before but can anyone please help me in adjusting the parking brakes in my car. I was searching online for adjustment procedure for MK3 GS model but unfortunately could not find one. There are plenty of help for MK2. 

So far I have learnt that there is adjustment nut in driver footwell, but the one thing which confused me is I read somewhere there is another pair of screws under the car but I don't know the exact location for these. Can anyone guide me whether these model have adjustment nuts under the car or it has only one adjustment nut in the driver footwell on the padel. 

In addition to these, please correct me if I am wrong, there are adjustment screws in rear brake discs/pads. 

Any help or guidance will be highly appreciated.

Thanks.

[Farqui]

You're right, the rear disks/drums have adjusters that can be tweaked with a screw driver/similar.

If i were you, then i'd be checking these first.

While the wheels are removed, you should also also pop off the rear drums and check how much material are left on the drum pads.

[Manee]

Thanks for your reply Farqui. The situation I am having is that my parking brake padel is going almost to the floor, which put me in thinking that there might be a need of shoe adjustment. 

As mentioned above the rear discs/hubs have adjustment nuts in them but before touching them I want to ensure that there is no other nut involved which I don't know about, as I don't want to put any unexpected tension on parking brake cable. Hence I want to know about involved nuts/connections. 

Again much appreciated your input. 

[Sami Tilander]

Hi Manee,

I was also suspecting the parking brakes of my GS450h, when I bought it few months ago: also my parking brake pedal was going almost to the floor. So I adjusted the parking brake shoes, and got the brakes even tested (in the yearly inspection): everything was fine, but the pedal still goes almost to the floor... So, I guess this is just normal.

Adjusting the parking brake is very simple (you can get the official instructions from the Lexus Tech):

1. remove wheel

2. remove the small rubber cover from brake drum

3. with a flat screw driver, tighten the adjuster nut until the drum does not move any more

4. loosen the adjuster nut 7 "clicks"

(you may want to remove the brake drum to see what kind of adjuster nut there is... and check the pads/shoes like Farqui mentioned)

BR. Sami

[Manee]

Thanks for your reply Sami. Much appreciated. I will update how I will get on, looking to do it over the coming weekend. 

[Britprius]

Once you have removed the drum "you will have to swing the caliper out of the way first" you can see the brake shoes. These have very little lining material on them when new about 3 mm only. They tend to ware at one end of each shoe, but as long as there is more than 1 mm they are serviceable.

John.

[Manee]

Thanks for your time John. 

Regards. 

[Manee]

Evening all

So finally I managed to sort out the parking brakes today. Took me some time but I finally sort it out. Pads still have enough to keep the car stopped. Now it's nice and firm with only 2-3 clicks and is not sinking at all in the floor. 

Thanks a lot for all your input. 

Manee

[Farqui]

Well done, how did you fix it?

[Manee]

Its pretty straight forward, only tricky bit is getting under the driver side footwell to undo/do 2 x 10mm nuts on the foot brake padel. There are two Philips head screws on each corner of lower trim level, nuts can be undone whilst brake is still applied, but once it's released to carry out the work, I think it's easy to do these nuts whilst the lower trim panel is off. 

The steps I tooks are 

First I undid the 2x10mm bolts. Quick tip is deep socket, ask me why 😁. I undid when the parking brake was applied, it made it so much easier. REMEMBER to release the brake afterwards before moving to take off the wheels.

Second step is take off the wheel AFTER securing/stabilising the car, don't forget to use wheel chokes or any thing which can be placed in front of wheel to stop the car from rolling. I used a piece of wood as wheel choke.

If possible use your tyre or any other stand/axel stand/wood as a dead weight under the car to prevent any mishap. 

Once the the wheel is off, take out the little rubber grommet. Quick tip is to use nose pliars, initially I used flat head screw driver but ended up it being inside the disc hub. So lesson learnt and used nose pliars on the next wheel. 

After removing the grommet need to locate the adjustment lever. All the YouTube videos I watched, showed the adjustment screw/lever is in 6 o clock position. Well it did not happen in my case🙄. I spent 45 mins looking for this adjustment leverage 😥. Anyway in the end I had to take off the disc from hub to locate it. I ensure that in this process I did not have the keys anywhere near the car as I did not want to take any risk for the caliper piston to shoot out. 

To remove the disc, first I remove the brake fluid reservoir cap to eliminate any  a pressure building in it, I then pushed the piston back before removing the caliper, quick tip is to use flat head screw driver to push the brake pad a bit, once there is a little gap to accommodate screw driver head, put the screw driver in it and use disc as a leverage to push the brake piston back. Once it's has enough space then undo the bolt on top of calliper and once undone caliper will swing down allowing enough space to remove disc. A 21mm socket will do the magic. 

Once calliper is off. The way to take off disc is to just tap gently but firmly on the disc with a small hammer, I used a solid rubber hammer to avoid any damage. It will loose the disc and the disc can be taken off easily. Once disc is off, rub its internals either with wire brush or with some sand paper lightly, to remove any dust or rust. Please ensure if you use sand paper don't go with full blown steam on either pads or discs as it will damage them. 

After taking off the disc I found that the adjustment screw was towads the end of the car i.e. 9 o clock position. After cleaning the pads and disc I put the disc back and checks the disc was freely floating. I then adjusted the lever/screw in question. I used a flat head screw driver and moved the lever/screw towards the front of the car. After few turns I checked whether the disc was still floating free or the pads are stopping it. Once the disc was stuck by pads, I loosened it a bit and once I was happy then I put the caliper and wheel back accordingly. I did the same process on both sides. 

After putting the wheels back and closing the brake resorvoir, I started to tighten the 2x10mm nuts on the foot padel, at this stage lowering the plastic trim really help as it gives some space to work on. As mentioned in the start, deep socket makes it a lot more easier as compared to normal socket, because to tighten these nuts with normal socket you have to do it in a awkward position 🤐. once the nut on back is tightened, the nut on the front (locking nut) can be adjusted accordingly and you can have a fully working parking brake with a foot padel that does not sink into the floor anymore. 

Please consider whilst tightening the nuts don't over tight them as they will over strecth the main cable. I kept checking the padel travel after tightening initially, once I was happy with the padel movement, I tightened the locking nut. 

This is how I adjusted my parking brake system, any suggestions to improve it would be highly appreciated. If you want to adjust your parking brake system, please do it on your risk as I will not be responsible for your actions. 

Thanks

Manee