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Discussion Starter #1
Ive searched all over- anyone have a good link to a video or guide to bench check a midland(band type) power brake booster

brakes were working fine when i removed booster
got the shells powdercoated
put back together, very difficult as the extra thicknesses of powder coating on both sides of the shell half flanges, plus the inner two sides of the clamp itself, but managed to get back together with some muscle.

Now- i have one of those mighty vac things for pulling vacuum, bleeding brakes etc-
ive sealed the back end of the booster with a master cylinder, the clamp is tight, new check valve and gasket and i plugged off the second hole in the check valve securely
i cant get vacuum up with mighty vac alone- should i be able to?
So i connected a hose from the check valve to an actual vacuum pump i have at work- the vacuum does get up to around 20- but the following happens
a) while the vacuum is solid, its much more difficult to press the rod in(the rod with the hole that connects to the brake pedal rod) is that normal?
B) after shutting off the vacuum pump and quickly pinching off the suction hose attached to the check valve, the pressure goes right down

bottom line- when vacuum is up- back end sealed with master cylinder and gasket, all hoses pinched, should it hold vacuum to some degree for at least an hour?




I spoke to dewy a long time ago about another booster and am sure he gets 20 annoying help me calls a day, so i'd like to help myself and figure out whether or not i need to send out to him

any help/links etc are appreciated
thanks!
 

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Your much more ambitious than I! I take the easy way out and get a replacement/rebuilt one....
Sounds to me like it's still having issues if it looses vac when you pinch it off? Maybe that check valve has some rust/dirt still..?
 

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Discussion Starter #3
thanks for the reply, i fogot to mention i checked the check valve by itself, and it seemed to hold fine
 

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It should hold vacuum for days if it is sealed properly. Also, you shouldn't have to pinch the line when you remove the vacuum if the check valve is working properly.
 
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