Brake Master Cylinders

[CriticalMass]

I was bleeding the front brakes today on ERA164. I opened the first bleeder on the front and when I went to pump the pedal it depressed as I would expect through about 50% of its travel, then got stiff for a moment, and then collapsed to the floor (the reservoir was full). Now I have a never ending supply of air exiting the system at the bleeder.

I pulled the master cylinder cover and there was some fluid leaking into the boot of the front brake cylinder which I assume began with the odd pedal travel, because the inside of the cylinder cover was dry and they have never dripped onto the floor in the past. So I guess I'm in the market for a new cylinder.

My question is do I need to replace both cylinders at the same time? If not, I'd prefer to just do the bad cylinder as it will eliminate the need to pull the inspection panel to bleed the rears.

If I can just replace the bad cylinder, I assume I shouldn't mix two different makes of cylinders. The manual says that from chassis #220 on, Tilton cylinders are used, but doesn't specify what was used prior. It's definitely not the Tilton on there now. I attached a picture of the cylinders. They're stamped with V-1089 and a Google search seems to indicate they're Volkswagen or aftermarket Volkswagen replacement units. Anybody recognize them?

If I do have to replace both at the same time, is it correct to assume that the Tiltons can replace these without modification on a pre-220 chassis?

Also, based on the manual, it seems to me that the balance bar is angled improperly...that it should slant away from the outer/front cylinder as opposed to towards it. Any idea what's going on here along with the bent rear cylinder push rod? The brakes have always performed nicely and the fronts lock up just prior to the rears, but the setup is a bit different than the manual describes.

On an unrelated note, should the pedal needle bearing be lubricated while I've got the cover off, or not necessary?