Brake issue 2022 (1 Viewer)

[Pennwestmechanic]

Sorry if this has been brought up but no luck searching the forums.
My 2022 gx is having a brake issue where the pressure slowly bleeds off while on the pedal. No leaks and level is full/Lexus has serviced it since new and I just bought this one used in February with now 59000 miles.
I had it towed to the dealer and they will look at it Monday.

So when I was stopped at a light the gx would start to roll and I'd have to press the pedal further with the same pressure. Obviously I knew something was wrong but once I let off the pedal I had a good pedal then it would slowly get soft again. Made it work safely cause I got to pay them bills!

Lexus history shows they have flushed the brake fluid twice so either something is goofy on that end of things or maybe the master cyl is failing? I look quickly and didn't see anything dripping.

No warning light either.

Any thoughts?

Thanks

 

[r2m]

Sounds like your brakes need to be bleed. If I'm not mistaken, it's not something you can just shade tree, I think you need Toyota's Techstream software on a PC to bleed breaks.
Somebody correct me if I'm wrong.

 

[Pennwestmechanic]

Sounds like your brakes need to be bleed. If I'm not mistaken, it's not something you can just shade tree, I think you need Toyota's Techstream software on a PC to bleed breaks.
Somebody correct me if I'm wrong.

Brakes have been fine since I bought it back in February. Lexus is the only one servicing it.

 

[Acrad]

Actually.. standard bleed works fine without TS… I flushed all of my brake fluid

 

[ericm979]

It there's air in the system the pedal will be soft and will travel farther, but the braking level will remain consistent. A sinking pedal would be a bad master cylinder. Or maybe a slave cylinder that's leaking, but you'd see fluid leaking from it. The master can fail such that fluid does not leak to the outside, just internally.

 

[Hiluxforever]

This is how my truck was until I upgraded the brakes.

 

[Pennwestmechanic]

I'll find out Monday. It did feel exactly like I was bleeding the brakes as the pressure would slowly let off and the pedal would need to be pushed further. Like I said earlier I looked quickly and did not see anything leaking and the reservoir was still on the max line, doesnt mean a bleeder screw could have been letting a few drops out at a time. I didn't want to push the pedal to the floor as I really don't like missing work so I had to baby it. Lexus just did a multi point service on it in July and shows the brake fluid was flushed again as it was done at 30k also in the service history.
I have seen master cyl fail and leak into the passenger compartment.
My luck is screwed up as I bought this to not be at the dealership for repairs. LoL

 

[Hiluxforever]

I'll find out Monday. It did feel exactly like I was bleeding the brakes as the pressure would slowly let off and the pedal would need to be pushed further. Like I said earlier I looked quickly and did not see anything leaking and the reservoir was still on the max line, doesnt mean a bleeder screw could have been letting a few drops out at a time. I didn't want to push the pedal to the floor as I really don't like missing work so I had to baby it. Lexus just did a multi point service on it in July and shows the brake fluid was flushed again as it was done at 30k also in the service history.
I have seen master cyl fail and leak into the passenger compartment.
My luck is screwed up as I bought this to not be at the dealership for repairs. LoL

My truck did this. I think it may have had the cheaper oem brake pads put on it, before I bought it. I upgraded to more aggressive pads and it has not happened again.

This affects a decent numbers of trucks with everything else being good. I personally think the oem brake pads are inadequate.

 

[Pennwestmechanic]

It there's air in the system the pedal will be soft and will travel farther, but the braking level will remain consistent. A sinking pedal would be a bad master cylinder. Or maybe a slave cylinder that's leaking, but you'd see fluid leaking from it. The master can fail such that fluid does not leak to the outside, just internally.

This is my thinking also of what has failed. Possibly normal out of so many I got the one that has to fail or maybe the dealer flushing the fluid caused it either by human error or something else.

Good thing will be seeing the new dealership they just opened up.

 

[Pennwestmechanic]

My truck did this. I think it may have had the cheaper oem brake pads put on it, before I bought it. I upgraded to more aggressive pads and it has not happened again.

This affects a decent numbers of trucks with everything else being good. I personally think the oem brake pads are inadequate.

I understand brake fade, but this was clearly right out of my driveway I noticed it. So no heat build up and didn't get worse driving 14 miles. I do prefer the oems as they are more ceramic make up and less dust to my liking.
If I towed often I would look at upgrading.

 

[Hiluxforever]

I understand brake fade, but this was clearly right out of my driveway I noticed it. So no heat build up and didn't get worse driving 14 miles. I do prefer the oems as they are more ceramic make up and less dust to my liking.
If I towed often I would look at upgrading.

Correct. It happened randomly, from cold to hot. Nothing like fade at all. More abrasive pads fixed it.

Even with positive pressure on the prake pedal.

 

[Pennwestmechanic]

Update: dealership cannot duplicate and I remebered this happening briefly before so I told them to keep it until it's fixed.