2015 RX350 hard brake pedal after start and stop driving

[XiaobinHao]

Hi All, 

      My 2015 RX350 ran fine until last month.   I did some shopping and when I came out to start the car, the brake pedal was very hard to depress, so I could not press the start button to start the car.   I had a friend come over and push the pedal down, started the car, and it didn't happen again for a few weeks.   I searched some forums and found that its probably either the check valve on the vacuum booster, or the booster itself leaking.  Since it happens rarely and I can park the car for days or a week and it doesn't happen, seems to be that it is probably the check valve.  Dealer won't give me a price to first replace the check valve, they just want to do open ended diagnostics.  I can't see how they can diagnose this if it happens once a month!   i think they want to run the bill up.

      Has anyone had this problem, and if so, any idea what a reasonable dealer would cost to first replace the vacuum check valve, grommet and vacuum hoes?  Best I can estimate its about 100.00 in parts, for real lexus parts.

Thanks!

X

[RX400h]

That may be a failing brake booster check valve.

This page shows where it is located. It looks to be fairly easy to replace.

2015 Lexus RX 350 Power Brake Booster Check Valve - 4473022150 - Genuine Lexus Part

The part itself is less than $45.

[XiaobinHao]

9 hours ago, RX400h said:

That may be a failing brake booster check valve.

This page shows where it is located. It looks to be fairly easy to replace.

2015 Lexus RX 350 Power Brake Booster Check Valve - 4473022150 - Genuine Lexus Part

The part itself is less than $45.

Thanks!