pressure bleeding brakes

So I am making a pressure bleeding cap for my 89 xj and I am wondering if anyone know's how much pressure I should use or not go over.I put 2 rubber valve stem's in a spare master cyl cap and plan to use a hand bike pump to build pressure .It has new booster and master new lines ,I bench bled the master and it still has lack of pressure if anyone has thought's on this I would like to hear them

Thanx :doh:

It doesn't take much pressure. Just about any positive pressure should do, but something in the 20's is probably about right. Of course the actual brake lines can take plenty of pressure, but the plastic reservoir and cap cannot, so you don't want to blow apart your adapter or unseat the reservoir.

The Motive brand power bleeders use 10-psi.
http://www.brakebleeders.com/power-bleeder-instructions.html.

An 89 should be a metal reservoir. I suspect you'd start pushing air out past the seal before you got the pressure too high anyway.

Thanks I have another question I have 3 inch stainless steel wrinkle pipe I was thinking might make a sturdy snorkle would the smooth wrinkles mess up air flow that much

thank you lawsoncl that is good info I have all fresh clean fluid I think there must be air trapped in the metering block

A little more background on what you are doing or trying to fix would be helpful.

The brakes up through 94 are pretty awful. 95+ have the dual-diaphragm booster and upgrading to that system will do wonders for your stopping ability.

A common error if the front calipers have been changed is to put them on the wrong sides with the bleed screws facing down--you will never get the air out of the system if that happens.

Yes, occasionally air will get trapped at the proportioning valve and cracking the lines there to bleed becomes necessary.

IF you have ABS that is the crummiest system out there up through 91 and really should be eliminated. That would be the perfect time to upgrade to the 95-96 or WJ MC/booster setup.