I got a new master for a 1998 dodge v8 dakota that bolted up to the booster perfectly and … Some 94's had a dual diaphragm but they are not very common. Unless you're having to stomp the brake pedal with your single diaphragm booster, I don't think you'll see much improvement swapping to the dual unit. A power-assist booster by itself retails for between $139 and $190. When I bd dropped it, I purchased a 7" dual diaphragm booster on ebay. A dual diaphragm … Swapped it out to a single 8 inch ,far better brake pedal feel and control.G body has GM Metric front calipers and rear drums.

Walkers wrote:Looks like brake code (rpo) JG4 and JD9 are dual diaphragm and JF3 and JL4 are single diaphragm. On the JL4 it looks like there is both a rear disk and a rear drum in that code. A dual diaphragm booster simply applies more braking force with less pressure on the pedal. The only part of my brake system I changed was this booster, did not disconnect any brake lines! Dual diaphragm brake boosters tend to give extra braking even when the vacuum from the intake manifold is low. Single vs. Dual Diaphragm Power Boosters.

BOOSTER SIZE is an important consideration. Now that we have told you which direction we would send you, we think it is important to understand what the number of diaphragms means along with the size. If the same car were to add a 9” single diaphragm vacuum booster the brake pressure would increase by 899psi with a total brake pressure of 1790psi. Given your vacuum level, a dual-8" or dual-9" booster would make a world of difference in your brake feel and performance. The following charts show the “free pressure” each size vacuum booster can provide. However the stock brake system on your Cabalero with the small single piston calipers and small rear brake cylinders doesn't require any more hydraulic pressure than the single diaphragm booster … The 899psi increase is “free pressure”. … Prolly not worth the time & money doing the swap unless your current setup is in need of repair. Smaller brake boosters … The car will make 891psi of brake pres-sure. In this case, we would recommend a 9” single diaphragm system which is a great choice for drum brake equipped vehicles. From that time my brakes have been horrible. Single diaphragm power brake boosters can produce up to 950 p.s.i. Boosters are available in 8-inch dual-diaphragm, as well as 9-inch and 11-inch single-diaphragm units. Inline’s combination units are available for $275, or you can add the correct proportioning valve for … They work well with four wheel drum systems or disc brake front/drum rear systems. So when I go to a smaller 9" booster (which I know will have less assist) WOULD using a smaller bore master (say 1" bore) ..about = the same amout of overall brake effect ? The factory single-9" unit was intended to be used with power drum brake applications, which require less pressure than disc/disc or … How much more help do you get and is a dual longer so it will be to long to fit inside a 65?

Works very well. I have a disk/disk and brakes are not good. Power brake boosters require 17" of vacuum or more to function properly. A dual diaphragm booster produces more hydraulic line pressure than a single diaphragm booster which of course is better. The simplest way to look at it is the booster … Brake boosters can range in size from the small 8-inch single boosters to the large diameter 11-inch single booster and everything else in between. The 78-88 G body GM cars has 7 inch dual boosters.....In an OT G body El Camino I found the stock dual booster to be too touchy,like a 60's Mopar. 11"single booster with big bore 1 1/8" master = 9"single booster with 1" bore master??? All 95's had the dual diaphragm brake booster it was the only and last year the YJ was sold with it. Normal stopping seems less than ok but if I need to stop quick or slam on the brakes, it doesn't stop. Whether you choose a single or dual diaphragm booster depends on how much brake assist your vehicle needs.
My booster started to hiss so I went to the pick and pull and found a dual diaphragm booster out the newest cherokee I could find, cut part of the rod off, hacked my stock rod/loop that connects to the brake pedal, setup the right length and welded it to the xj booster. Somebody said it looks like I have a single diaphragm booster with a 1" bore best suited for a disk/drum setup.