so i just did a swap, i put a ford 9 inch in my 87 iroc and it has drum brakes with the new rear, and the car stock had disks out back, now do i need to change my prop valve to run the drums in the back or cna i keep my prop valve as is ....i do have the prop valve that came from the same car as did the rear so i can change them but rather not if i dont have too...

 

Yes you should change the prop valve. I would suggest an adjustable prop valve, but I don't see why the parts car wouldn't work.

You need to change it cause, the drums take less pressure, and the disc take more.

 

Sorry, I'm a bit thick headed this morning. You say you have the prop valve that came from the same car as did the rear. So the prop valve is a Ford part?

JamesC

 

no, the rear is a built unit from currie inc that was in a 86 camaro...

 

Change it, yes. But whether it will bolt in will depend on what years they are from.

Ed

 

86 to 87 if not...ill jus make some new brake lines then and throw the line lock in that i have been putting off

 

hey man...from what i'm reading i'm assuming you mean you picked up the 86's drum prop valve, but if you need one i got my 88 drum if you need it.

 

yeah i had my oby who got rid of the car after i took the front and back suspension out of it....i had him take the prop valve out which was in the car with this rear and worked...

i just want to kno if i have to change it and if i do, will it fit or do i have to do new lines....the reason im askin is cuz brake fluid eat paint...and i dont want to repain my engine bay i got nuff things to do

 

shouldn't pour out, but i would suggest replacing it with the drum prop valve...as mentioned drums use less pressure, so you will be locking the rear up.

I don't see how the adjustable prop valve would taper down the pressure, although i do not fully know much about them. I can see that it easily can raise pressure, just don't understand how it would bring the pressure down for drums.

 

The adjustable should bring press up and down as you need it.
You should be able to keep the prop valve you have with an adjustable one. You will just have to "turn down' the press with the adjustable.

Call summit or jegs and ask them too.
I know summit's tech line is, 1-330-630-0240, don't know if jeg's has one or what their # is, but you have to call summit's tech during the day. I'm sorry I don't remeber the hours either.

So long as I recal and assume correctly, the rear take less pressure, cause the rotation of the drum "turns" the shoes and pulls them out, usuing the turning motion to add pressure, also they are the rear, you want more in the front, but rotors take more pressure, cause they just push straight out.

To who said that they don't understand how an adjustable can lower pressure, look at it like a water faucet. (outdoor you would hook up a hose to, to wash your car)
If you turn the faucet on a little you don't have much pressure, the more you open it the more pressure and volume you have. Same idea, the pressure it there before the valve (faucet), but the valve (faucet) regulates it. The more open it is the more pressure you have.

What I don't know is if you can turn them down to 0, but you obviosly have to have some press.