How or can this check valve be tested, and if need be, repaired to good order, or must it be replaced?
Thank you
Carlo
The way you check it is, with car at standstill and handbrake on, to start your engine, let it idle for 30 seconds, and then turn it off.
Wait 10 seconds after engine off and then pump the brake pedal and see how many times you can pump it and still feel the assist. You may want to repeat the test after waiting 20 seconds after car is off
If the valve is gone, there will be no assist with engine off. If valve is slightly defective and leaking, you may only get a pump or two before all the vacuum has leaked from the storage tank
Dennis 69 OTS
3 Likes
Thanks, Dennis- I’ll give that a shot.
BTW- if it tests n/g, can it be cleaned or repaired?
No it cannot be prepared. It is very cheaply built and never seems to last very long.
I have replaced mine many times and recently used an American part in its place
that seems to be very good
Do tell us how yours works out
Dennis 69 OTS
Dennis- Okay, understood. May I ask which American part you used? I read in a search result on this forum that NAPA sells a good one, but searching NAPA came up with nothing.
Thanks
Carlo
I epoxied it to the old valve.
Not the most handsome outcome but it works.
Be careful and use very little epoxy as you don’t want epoxy sucked into the new valve rendering it defective
Let it set for 48 hours
Dennis 69 OTS
I was about to ask how you got it to attach. Good show,. 
A few weeks ago at the huge AACA flea market in Hershey, PA. (9000 vendors) I found a vacuum tank that was a dead ringer for the late 150 tank. It’s like the E, but different mount and no flat spot like the E has. The vendor said it was from an American car and when I looked it over, I saw the valve was all brass. I bought it for a few dollars for the valve. The guy said he never sold any tanks before as they never rust and the valve never leaks.
Phil.
Phil.
1 Like
Here’s a link to the original style from SNG…
https://www.sngbarratt.com/us/#!/English/parts/2ca14e25-c18f-4e16-90d2-cac5347e4d6f
I will never buy a stock servo valve again. They just don’t last and when you open them up, you can see why!
American part?
It’s easy to check too on a 3.8, just by pressing the button on the Kelsey Hayes booster. The booster should operate several times after you’ve switched off the engine. Incidentally, the original booster check valve on my 3.8 still worked fine right up until I sold the car recently.
Hi try to find an original that works, most of the new reproduction Chinese crap ones do not work at all.
Regards,
Allen
I just took mine down to the local parts store and bought a generic replacement.
LLoyd
Wherever space and time interact, there is information, and wherever information can be ordered into knowledge, and knowledge can be applied, there is intelligence.
Pavel Mirsky, mid 21st Century Russian General
Well the one that a picture was posted of, says on it made in China.
Ditto: Tweety’s was 1963 OE, and still worked fine till I sold it, in 2016.
In testing my check valve I’m using a MityVac attached to the port that goes to the tank, and a finger pressed hard against the port that goes to the booster…this is of course with the valve on the bench. With the set up mentioned, how long should the vacuum hold? I can get mine to hold for about 10 -15 secs…solid if just blocking the MityVac so it’s not that that’s leaking…10-15 secs ok? The replacement wont hold that long!
I must tell you how happy with the aftermarket american valve. It holds the vacuum in the tank for hours!!
Looks like I may be going the route of splicing in a generic modern day check valve, but I’d like to make sure I’m testing the stock valve properly first. And, if my testing method is correct, I’ll need to let the company I bought two new ones from know they are bad, right off the shelf!
Below is a picture of how I bench tested the three valves I have. With all ports “fitted” as shown, I was able to get each of the valves to hold vacuum. However, as soon as I removed my finger from the top port, the vacuum would drop to zero, in all three cases. My old valve actually took 3-4 seconds to bleed to zero while the two new ones were pretty immediate.
Based on my knowledge of how these should work, these tests tell me the check valve in all three valves are bad. Am I missing anything or do I have it wrong?
Thanks all!
RobY
No, not testing correctly. The “black” port should have vacuum. Block one or the other of the red or blue ports, and put your finger over the other. When you remove vacuum, you should feel it hold.
I had replaced the entire valve with a combination of a T fittting and a modern valve. But I found it very hard to look at, and as we know that once it’s on your mind you keep looking. So I bought a stock replacement, which has held up for more than twenty years. Not sure about the quality of the new stuff, but they used to be reliable.