Booster Check valve fix or replace?

[hugho]

We have cold winters in Wyoming and this winter the dreaded frozen brake pedal finally hit, no brakes until the truck warmed up. All of the posts I could find recommended buying an OEM Toyota replacement. My 98 4R with 260 K miles did not have a plastic body check valve like most Toyotas. It was steel. I reasoned that maybe I could clean it. I removed it and soaked it in parts cleaner and then blew it out and added carb cleaner and soaked it and blew it out again. This morning it was -19. I cranked it and I had brakes ! Before I didn't have brakes if it dropped below 32 degrees. I am hoping this is a semi permanent fix and I ill amend this post if it fails again. Save your money.

 

[3bears]

all of mine have had the metal check valve, I have had the issue you are talking about with my cold temps. I too just cleaned it like you and it was good to go. I thought I would order one in case the cleaning was a short fix. New one has been on shelf for 2 winters now.

 

[T4R2014]

What is clogging these valves? Engine oil vapor from a bad PCV system?

 

[phattyduck]

What is clogging these valves? Engine oil vapor from a bad PCV system?

No, water vapor turning into a small amount of liquid water in the check valve. The engine pulls vacuum through the booster, so it is sucking air in through the booster (small amounts) with each brake application.

-Charlie

 

[3bears]

No, water vapor turning into a small amount of liquid water in the check valve. The engine pulls vacuum through the booster, so it is sucking air in through the booster (small amounts) with each brake application.

-Charlie

agree, when I had my issue, there was no oil residue so assumed it must have been moisture that caused the issue