brake pressure gauge...usage?

elgecko · #1 (**permalink**) 07-23-2009, 06:58 PM

After a year or so of honey-do's, I'm back.
Things are running but now I gotta get things stopped!!!
I'm getting a hard pedal but very little pressure. Am I using the brake pressure gauge correctly?
Any secrets?
Want to make sure I'm using this gauge correctly before I invest in smaller master cylinders.(Any for SALE?)
I have a Wilwood dual floor mount with 3/4" front and 1" rear cylinders.
Only getting 500 - 600 pressure at wheel cylinders.
Thanks
Dave

strictlypersonl · #2 (**permalink**) 07-23-2009, 07:15 PM

100 lbs at pedal x 5:1 pedal ratio, divided by two (force split between the two cylinders) divided by the area of the master cylinder (1" > .78 sq in.)= 340 psi.

So, you're pressing pretty hard.

elgecko · #3 (**permalink**) 07-23-2009, 07:58 PM

Yeah wasn't sure of the recommended pressure. Haven't driven car out the door yet. Just checking things
before the GRAND moment.

elgecko · #4 (**permalink**) 07-26-2009, 04:27 AM

What I don't understand is that wilwood said.......quote.....
"With a 5/8 bore master you should see about 1935 psi and with the 3/4"
bore, your psi will be about 1364 psi. This is based on the information you
provided for your 6:1 pedal ratio."
So.... people are saying 300-4000psi at the wheel cylinder is fine but wilwood is saying
over a 1000 psi is a good reading.
The instructions with the gauge I'm using says don't drive a car with less than 900 psi.
I'm lost.
I do have a 5/8" front and a 3/4" rear MC setup planned.
Dave

strictlypersonl · #5 (**permalink**) 07-26-2009, 06:38 AM

See my analysis over on the other thread.