I was told that when I switch to disk brakes from my rear drums that I will NOT have to change my proportioning valve on my 1986 Iroc because that it originally came with aluminum drums. Is this correct?

Thanks

Chris

 

no, if you have an aluminum PV, flat sided machined looking you don't need to switch, if you have a roundish cast looking PV you do

 

It makes no diffenence if you have Aluminum or Iron Drum brakes
now, you will have to change the Proportioning valve for Disc Brakes,

 

So ede says I do not have to switch and DJP87Z28 says I will?

By the way, I do have the flat sided machined one.

Thanks

Chris

 

either take the prop valve from the donor car or get a pair of adjustable ones from jegs i did the conversion without the prop valve and its been hell ever since so far ive had to change the rear calipers at least 3 times im gonna go with the adjustable ones

 

Were you trying to say " I have aluminum drum brakes now"??
And do you need to change the present prop valve used with the Alum Drums???

 

Correct. I have the aluminum drums on my car right now with the square machined proportioning valve. I was wondering if I need to change the proportioning valve when I switch to rear disks.

Thanks

Chris

 

All right, at least that clears up that point. Yes I would change the Proportioning valve. Get the one from the donor car if possible, or buy a new one for a Disc brake application.