SledDawg2
Veteran Member
I am having a boot problem.
I started my diagnosis by reading the thread histories here on the forums.
I found a few vacuum hoses worn and frayed so I replaced all of them. I also discovered the Black / White check valve to be dead so that was replaced too. I did verify that the new check valve was good prior to installation.
After a test drive I found the new check-valve to be as dead as the old one.
Can anyone tell me what would "kill" a this component so quickly
Update:
I connected a vacuum gauge to the first small nipple after the vacuum pump and I have a reading of nearly 30" of steady vacuum.
I then connected the gauge to the vacuum line at the black side of the check-valve and also have the same reading (30").
Where things get strange ...
When I turn off the engine there is no "residual" vacuum to cycle the change-over valve (anti-shudder valve) nor is there any residual vacuum at the black vacuum "reservoir".
When I replaced the vacuum hoses I was careful to replace only one line at a time to prevent any mix-ups.
My next question.
There is a (2nd) vacuum check-valve.
https://farm9.staticflickr.com/8722/16872254906_166acf578c_b.jpg
It is item #10 and it is part of the semi-rigid line to the brake booster.
My question is if this check valve is defective what symptoms would it cause ?
Update #2
I removed item #10 the 2nd check valve to the brake booster.
This check valve retains vacuum to the brake booster.
My check valve (#10) seems to be functional.
I started my diagnosis by reading the thread histories here on the forums.
I found a few vacuum hoses worn and frayed so I replaced all of them. I also discovered the Black / White check valve to be dead so that was replaced too. I did verify that the new check valve was good prior to installation.
After a test drive I found the new check-valve to be as dead as the old one.
Can anyone tell me what would "kill" a this component so quickly
Update:
I connected a vacuum gauge to the first small nipple after the vacuum pump and I have a reading of nearly 30" of steady vacuum.
I then connected the gauge to the vacuum line at the black side of the check-valve and also have the same reading (30").
Where things get strange ...
When I turn off the engine there is no "residual" vacuum to cycle the change-over valve (anti-shudder valve) nor is there any residual vacuum at the black vacuum "reservoir".
When I replaced the vacuum hoses I was careful to replace only one line at a time to prevent any mix-ups.
My next question.
There is a (2nd) vacuum check-valve.
https://farm9.staticflickr.com/8722/16872254906_166acf578c_b.jpg
It is item #10 and it is part of the semi-rigid line to the brake booster.
My question is if this check valve is defective what symptoms would it cause ?
Update #2
I removed item #10 the 2nd check valve to the brake booster.
This check valve retains vacuum to the brake booster.
My check valve (#10) seems to be functional.
Last edited:
