if I have 1LE style brakes in the front and 89+ PBR brakes in the rear on a 1985 Z28? I noticed in the sticky 1LE thread that the two proportioning valves listed are broken down for 82-88 and 89+. It is not clear if this is because of the difference in the rear brakes (older style rears vs. PBR 1LE rears) or maybe because of routing or brake line changes.


thanks.

 

according to andyz28 the 1LE combo valve.....

1st design 14089496 89.5' and older

if your existing line comes right out of the front of the valve, you will need to modify the existing hard line to make it work.

 

but he doesn't sate if the reason is because of plumbing differences or because of the diference in rear brake designs that are totally different. That's what I'm wondering. Yes I have an 85, but I have a 92 rear with 12" PBR brakes.

 

It is not clear if this is because of the difference in the rear brakes (older style rears vs. PBR 1LE rears) or maybe because of routing or brake line changes.

It's brake design difference. Get the late style '89-'92.

Don>>>

 

thanks.

 

You will need the Proportioning Valve for the PBR rears a 89 to 92.

 

I disagree fellas. The differences in the prop valves are based on the thread pitch of the tubing threads, not on year model brakes. James should use P/N 14089496.

The following quote is from Daniel Burke's site and (hopefully) should clear this up.

1LE Combo Valve (proportioning valve)

14089496 1989 1st design: M1.0 tube nut threads (For 1982 - early 1989 applications)

10136840 1989 2nd design: M1.5 tube nut threads (Late 1989)
10136840 1990-'92: M1.5 tube nut threads.

Measure your existing brake line tube nut threads before ordering. The Master cylinder tubes have one that is M1.5 and one that is M1.0 so don't worry about them. Worry about your existing brake lines to the calipers and rear axle.

I used the 14089496 1st design because my car was built in 1984.

Mine required some relocating of the rear disk brake line: My old combo valve had the line coming in the front, whereas the 1LE piece had it coming in from the bottom of the valve. My existing line bent with no problems. Be prepared to replace that line if it's at all corroded. It might crack.

Here's his site's link:
http://www.ws6transam.org/1LEbrake.html

It's some good reading.

Hope this helps. FWIW, I also ordered P/N 14089496 for my 1988 Iroc. I will be installing it this week.

Ed