2015 GS350 AWD (NOT F Sport)

Even at red lights, I have to press super hard to stop car from rolling forward! And even if I let off my foot just the slightest bit, the car immediately moves forward!

But the overall braking is acceptable to come to a stop, even though I have to push the brakes slightly harder than before for full clamping

any advice on how to fix?

Should I choose:
1. Do a Brake Flush?

2. Do a brake bleed?

-got new brake pads/calipers in 2022 (at Canadian Tire)

-brake flush (and refill) in 2021

 

You should have the brake hoses checked to make sure one isn't ballooning somewhere.

 

Do you think it’s just a Brake Flush requirement to bleed out air and debris?
can I get a brake flush done at a Toyota dealer?

I read it could be a master cylinder leak. Anyone know how much that’d cost to fix in Canada?

 

So my big question is when did it start, immediately after getting brakes done, or down the road? Diagnosing without knowing the timeline, the conditions, etc make it very difficult.
I had a ripped rear caliper seal, made braking a bit tricky until I put new calipers on, only driving I did was straight to the shop.

 

My local Toyota dealer has done a very good job servicing my ‘15 GS.

 

It sounds like you’re going to have a mechanic do the work, so why don’t you take it there and have them diagnose it and recommend what needs to be done? Then you could report that back here for opinions if need be. I would think any mechanic/dealer can probably handle a brake issue; as far as I know this car does not have anything exotic in the braking system…

 

As others have suggested, have your car looked at by a mechanic. It should take almost zero brake pedal pressure to hold your car at a stop.

It would be interesting if you could post more information about this such as when the brakes were serviced, parts, etc, and what the solution is.
Thanks in advance.

 

I think a brake flush or a brake bleed will have zero impact on this.

This sounds like a classic booster issue. The fact you can stop it but it takes excessive effort tells me the basic hydraulic brake system is functioning. What you are missing is the power booster assist.

Do you hear a hissing under the hood while it is running?

Look behind the brake master cylinder and you should see a big round disk. This is your power brake booster. There is a vacuum line that runs to it. Make sure it is a) connected at both the booster and the other end at the intake as well as b) not cracked/torn/loose.

 

This is a very good question..

I think this issue most likely slowly started after my brake flush in 2021… (I had specifically told dealer to to flush, not just refill).

 

I went to a Toyota dealer near me and service department said “we refuse to touch a Lexus”..
lol..

 

awesome information

And I don’t hear a “hissing noise” when the car is running in general. (I don’t think I hear it either when I brake)..

 

The booster can fail internally and stop providing boost but it will usually cause a hissing sound as the vacuum escapes.

With the car off, are the brakes harder to press than when it is running?

If the booster had any vacuum stored, it would feel slightly easier the first time then get progressively harder to press. If not, the booster isn't holding vacuum at all and is possibly bad. A decent independent shop should be able to tell you in a minute or two.

 

Is the brake pedal going further to the floor than normal?

How long/miles from the last new brake pads and/or rotors?

 

This is likely the culprit. I had the same issue. Replaced the unit and all was working well.