I have a 1994 Honda Accord US Wagon. When the motor stops the brakes have no boost at all. I also have a Nissan Primera & the booster retains its vacuum when switched off, sufficient for about 3 applications of the brakes, which is normal. Could the non return valve to the booster be faulty? It has done 163,000 km.
It could be either the valve or the booster; they're about equally suspect. The hoses to the valve should not affect the ability to retain vacuum. The valve is easy enough to check by pulling it out and giving it The Kiss of Test. You should be able to blow through it from the booster end to the hose end but not the other way. Now wipe that silly black ring off your lips. :-)
If the valve tests okay you are probably in the market for a new booster. (The "probably" is from doubts whether pushrod adjustment can cause your symptoms - you can check the adjustment by following the link below.) Replacement is a medium DIY project with tight spaces, and wrecking yards are the most affordable source (I paid $75 US to a they-pull-it yard for the last one I did.) If you have to replace it, and you go the DIY route, check
Mike
it should retain vacuum. as mike says, test & replace accordingly.
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