Master brake cylinder not coming back

[rcolijn]

Hey all,

I have reconditioned my master brake cylinder, this means a thorough clean, new valve seat, spring, piston and boot. She pumps ok but the piston does not readily come back all the way, in fact it takes quite a while. So I soaked her in degreaser and sanded the inside with 400 grit. This seem to make it a bit better but certainly not happy.

Am I missing something or should I sand a bit more?

I seem to just sand the metal as she is squeeky clean.

A second question is about replacing it for a dual reservoir one, as mine is bolted to the frame but on the right side (converted to RHD) are the kits simply a bolt in or should I worry about complicated conversions?

Thanks guys,

ps, I have an original optional brake booster still to install, would that make a difference to the returning of the pedal?

[oldtime]

There are two ports going between the supply resevoir and the pressure cylinder.
One of those ports is very small. Make sure its clear via a wire probe.
You should ligthly hone the cylinder with a fine cylinder hone.
Then observe the cylinder bore in direct sunlight for evidence of defects.

For dual safety master cylinder upgrade please see: http://z4.invisionfree.com/CJ3B_Bulletin_Board/ar/t2591.htm
I can tell you that the Aussie RHD will mandate the need for a special master cylinder.

In service I have experienced no actual problems to date using the standard single stage master cylinder.

[rcolijn]

As always, thanks mate, good stuff. I have it working at the moment, sort off:)

I sanded a bit more and than twisted the old spring into the new one so it has the length of one spring, but the strength of two:) It seems to work fine, and I reckon will improve over time. Talk about bush mechanics...

I will order a new one when the budget master allowes me some more...

[Daryl]

The bracket for the MC would have to be replicated to mirror a right hand mount. It really is just a stamped piece of steel with 2 bends though. I built a couple of them before Herm had them readily available.
I have experienced brake failure twice myself with a single pot MC. Both times involved damage to sheet metal and the gutsick feeling of foot on the floor and nothing happening brake wise.
I have also had a wheel cylinder blow with a dual MC and it was just a press harder and come to a controlled stop much slower as half the braking system still functioned.
40 years ago when nothing on the road had very good brakes it really wasn't that big of a deal to have 9" brakes and a single pot master.
Today's world is a whole different story though. When you have 1500 pound cars zipping in and out of traffic with 4 wheel anti-lock disc brakes that can stop from 35 mph in 2 car lengths, the factory installed Willys braking system is just plain inadequate for daily driving in any type of urban setting.
It really doesn't matter how careful that you drive or how slow you go when someone stops dead in front of you in traffic.
Unless you have a 100% original show piece that sits in a museum, there simply is no reason not to run better brakes on a vehicle that gets driven in an urban enviroment.
I will now jump down off my soapbox and go back under the Jeep in the driveway.

[rcolijn]

Thanks for your reply Daryl, and see your point totally. I would like the change so will attack when appropriate money wise.

I was lookingt at the kit and can not see why I could not simply bolt it on the other side of the truck. It looks identical on the right and left hand side. Doesnt it simply have two bolt holes though in it? All I had to do is make sure those two holes align with the bracket I allready have for mine at the moment, than ensure the push rod from the pedal aligns niceley?