Bigger than 1" master cylinder that will work with a new double diaphram booster

[chadjans]

Okay I need to find a brake master that will work with a later model double diaphram booster? I have tried the 1999ish to 2000ish Dodge 2500 and a 1999 dodge durango. None of them will seal correctly to the booster.

This is on a 1993 Jeep Grand Cherokee. I do not want to down grade the booster to a single diaphram to get a bigger master...

Any ideas?

[rock-rod]

Originally Posted by chadjans

Okay I need to find a brake master that will work with a later model double diaphram booster? I have tried the 1999ish to 2000ish Dodge 2500 and a 1999 dodge durango. None of them will seal correctly to the booster.

This is on a 1993 Jeep Grand Cherokee. I do not want to down grade the booster to a single diaphram to get a bigger master...

Any ideas?

what booster are you running? Got any pics?

[chadjans]

Stock 1993 jeep grand cherokee booster.



And stock 1" master. (Top one)

[rock-rod]

doesnt the ford van e350 master fit that application too?

[chadjans]

Originally Posted by rock-rod

doesnt the ford van e350 master fit that application too?

No. Stock uses the funky tube into the booster. Which can be found on the Durango master but the mounting foot print and the seal to the booster will just not work. Too wide and the diameter of the seal surface is too small.

[geberhard]

you can grind teh Ram master slightly to fit. My booster looks pretty much just like yours...

see this thread: http://www.pirate4x4.com/forum/showt...=334736&page=9



and

[chadjans]

How did you deal with the ram master not having the tube that the push rod sticks into? And is there an indentation where the master sits?

[geberhard]

Chad, you can extend your push rod on the booster side. (the center piin on your booster). It hsould unscrew, and then you can puta longer bolt or allen head shaved up. measure the length until it touches teh inside of teh ram and how much travel is needed to brake, and adjust accordingly.

[Bradford]

go here, the one i did

http://www.jeepkings.ca/forums/showt...851#post759851

If you are doing the disk/disk setup on a one ton, I would find a ram disk/disk master, I used the disk/drum but am using 1/2" smaller diameter pistons in the rear so it worked out alright for me.

It does not look like the exact same booster, mine is a 95, fit with zero modification, the lines would have bolted up if i didnt convert the rear to single flare (ya i know incorrect).

Bradford

[chadjans]

It appears to me the boosters are different from 1993 to 1995. Different part numbers on Napa's website. It also appears to me the rod in the booster is not unthreadable. There are some shims on the end of mine that I beleive are used for adjustment. Vary the shim stack. Looks like my best option is a 1995 booster and a 2000ish Dodge ram master.

[chadjans]

Originally Posted by geberhard

you can grind teh Ram master slightly to fit. My booster looks pretty much just like yours...

Seams on the case are different. I don't beleive they are the same.

[Thrash]

I'm still confused as to what the fit should be. Should the rod just touch the cylinder when the booster and master are bolted together? Or should there be some initial pressure on the master? Or should there be a little gap to ensure there is no pressure when you are not on the brakes? Any insight is appreciated.

Thanks,
Whit

Originally Posted by geberhard

Chad, you can extend your push rod on the booster side. (the center piin on your booster). It hsould unscrew, and then you can puta longer bolt or allen head shaved up. measure the length until it touches teh inside of teh ram and how much travel is needed to brake, and adjust accordingly.

[geberhard]

I tuned mine until it worked, took a few tries. Mine is touching, slightly pushing.

[chadjans]

Bringing this back from the dead. I picked up a newer double diaphram booster. And again a 2000ish Dodge ram master. My stock master has a funky tube that the pushrod rides in. And the ram master does not. Do I need to find a master that has the tube? I know a dodge dakota master does but the diameter is only 1.125.

[bnine]

Why would you think you need a 1.25" master? 1.125 should be more then enough master for your rig.

Anymore and you are going to start losing signicicant braking pressure.

I run a 1.0625 which is 98 dakota on chev 3/4 ton calipers and my pedal stops less then halfway down.

[chadjans]

I am running Ford dual piston calipers up front and chevy half ton / three quarter ton disks in the rear. I have been told bigger is better in terms of masters.

[bnine]

Originally Posted by chadjans

I am running Ford dual piston calipers up front and chevy half ton / three quarter ton disks in the rear. I have been told bigger is better in terms of masters.

Very common misconception on the net.

As small as possible without hitting the floor will provide the most braking pressure you can get.

As in you try as small as you can, and move up as required. You booster is to small, and not matched for a 1.25" master. You will have less then satisfactory pressure with that size of master.

If you cant move the volume with the smaller master, and end up with a 1.25, you will require a bigger booster, or hydroboost to get back into the good pressure range of 800 plus PSI.

The bigger master only moves more volume. It does NOTHING to improve braking power, and actually does the inverse when used on the same booster that was originally equipped with a smaller master.

The worst advice on the net is almost always the brake mod threads.

just to clarify. The large master will work. The difference is, working, or working good/properly.