police vs. non-police cardone booster?

[BerniniCaCO3]

Replacing my hissing booster soon.
What's the difference?
I presume that i have non-police; police is actually cheaper. Still compatible?

non police:

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_20690070-P_x_x?cm_mmc=CSE-_-Google-_-VALUE3-_-VALUE4&ci_src=14110944&ci_sku=#utm_source=cse&utm_medium=google&utm_campaign=value3&utm_content=value4

police:

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Power-Brake-Booster-Cardone_20690069-P_250_R%7CGRPBRHYAMS_____

I know there's an aero/whale booster that will work, too-- if I got the master cylinder included in that package, would the aero/whale master cylinder still bolt right up? I feel like it's not a bad idea for marginally more money to replace the master cylinder with the booster.

[chitownvic]

Replaced mine not to long ago and do yourself a favor and paint it mines allready rusted and its been 6 months and I would think the diff is size Id imagine the PoPo one is larger??

[TomO]

I've noticed mine's starting to hiss a bit too. I've never changed one. What's the basic procedure for replacing it? In other words, how hard is it to do?

[chitownvic]

Yea I accidently drilled a hole into mine Haha.. Its not bad about an hour or two just push the brake lines outta the way and disconnect the brake pedal and crap I think 4 or 6 bolts holds the booster in place I dont remember

[gadget73]

Don't use the whale/aero master cylinder if you have rear drum brakes. Theres a valve in the master cyl to keep a couple psi on the rear wheel circuit so the cylinders don't leak. If you remove that, the rear brakes will likely do funky things. You can use the later booster though. Should be no practical difference in the police vs non-police booster. The aero/whale one has more total diaphragm surface area, so it has more assist.

[BerniniCaCO3]

will a new check valve likely be included with a new booster?

Good point on the aero/whale master cyl. I knew that about rear drums, just wasn't thinking about it. Those couple psi are just to keep the pistons in contact with the shoes, right, so that when you go to stop they start pressing on the shoes immediately? If you didn't have some held line pressure, they could back in...?

[1987cp]

I've read that the residual valve is supposed to be more like 10psi for drum brakes. According to whatever hotrod site I got the info from, (The Brake Man?), this is normally combined with a "metering" or "hold-off" valve that doesn't send pressure to the front brakes until line pressure exceeds 100psi. I've driven a car with neither, and it did tend to have premature front lockup.

Apparently streetrod guys use 2psi residual valves for disk brakes, but I read that that's unnecessary unless the master cylinder is mounted down really low, like under the floor, and that normally gravity is plenty to keep 1-2psi residual pressure anyway, so a normal car shouldn't need a residual valve inline with disk brakes.