Hard brake pedal solved - Vacuum issue -

[ølaf]

Hmmmm .... do you really think a leak in the booster could cause a lean air-fuel ratio? How about just plugging that vacuum line or nipple, clearing the code, and see if it trips again?

- olaf

 

[HiLife]

I still have to troubleshoot further to confirm that is my issue.
All the air entering the intake has to go through the maf where it is measured by the ecu. Any extra air after the maf gets picked up the the air/fuel o2 sensor and triggers a lean code.

 

[HiLife]

Update: it ended up being my brake booster was my hard brakes issue. Replaced with a Toyota unit and all is fine again.
At first, I switched out the booster hose with a toyota one, no change. Switching out the check valve with a toyota one, no change.
My short term fuel trims pegged into the 19s everytime I stepped on my brakes while the rig was moving above 5mph. Let go the brakes and stft went back to normal +/- 2. During all of this rig ran fine. No jump in rpm like you get with a vacuum leak, no rough running.
The bad booster did set a P0171 code, even after I erased it.

 

[FD7683]

Sorry to bump an old thread. Is it possible to remove the check valve and clean it with lets say brake cleaner? Servicing brakes and my pedal is rock hard on a cold morning. I know people like to clean PCV valves when they are clogged but I want to see if this method can be applied to the check valve before I replace it with a new Toyota part.

 

[ølaf]

I know people like to clean PCV valves when they are clogged but I want to see if this method can be applied to the check valve before I replace it with a new Toyota part.

Certainly worth a shot. You can also remove it, and put it into your freezer, then try to suck through it in the right direction, to see if the booster valve is the problem. Most people just swap them out with an OEM one, when they experience your symptoms. It's one of the cheaper parts to throw at the problem. If you do go that route, make sure to get a new grommet as well.

Keep us posted!

- ø

 

[gamefreakgc]

Sorry to bump an old thread. Is it possible to remove the check valve and clean it with lets say brake cleaner? Servicing brakes and my pedal is rock hard on a cold morning. I know people like to clean PCV valves when they are clogged but I want to see if this method can be applied to the check valve before I replace it with a new Toyota part.

It is only plastic so yes, definitely something you can do! Can't really hurt it unless you start jamming something through the valve. Best to diagnose and possibly replace the cheap stuff before the more expensive items.