1LE master cylinder and proportioning valve - Third Generation F-Body Message Boards

bjankuski · 10-27-2002, 04:26 PM

I have a 1988 formula with the J65 brake system (4 wheel disk) I have converted my car to 1LE brakes on all four corners my question is do I need to change my master cylinder and proportioning valve? When I went to the dealer and looked up part number he told me the 1988 1LE did have a different master cylinder then my J65 setup, the part number was 18009374 which was the same master cylinder used on all 1989 and latter J65 and 1LE brake systems. He also told me that the 1988 1LE proportioning valve was the same as my 1988 J65 setup, the part number was 14089497. In 1989 he said the 1LE brake system changed the proportioning valve to 10164112 which is different then my 1988 J65 and 1988 1LE setup. He then told me that the threads were different between the two proportioning valves and I could not just bolt in the 1989 and latter 1LE valve. So my real question is do I need to change to the 1989 and latter 1LE proportioning valve to get my 1988 system 1LE brake system to work to its full potential? Why does 1988 have the same proportioning valve as mine but 1989 is different? Do I need different lines (threads) to bolt in the 1989 proportioning valve?

The dealer also told me that he would not change the master cylinder or proportioning valve from my J65 to the 1LE setup because he felt there would be no difference in operation, has anyone tried this?

Thanks

ANDYZ28 · 10-27-2002, 05:23 PM

I believe the answer is contained in this old post by me; http://www.thirdgen.org/techbb2/show...threadid=59878

It was a "sticky" post for a long time. Then it was removed for some reason. It has helped a lot of people like yourself.

Thanx,ANDYZ28

ebmiller88 · 10-27-2002, 07:19 PM

The dealer guy is wrong..You have to change both the prop valve and M/C. Andy is right, and if you checked his thread you will see that. I did the swap on my '88 J65 car and here's what I used:

New combo valve (PN 14089496)
Disc/drum car M/C (PN 18014286)

These are the parts you HAVE to switch. The M/C threads will be fine, but you HAVE to get this prop valve in order for it to have the correct threads you mentioned, which are the 1st design /early threads (1.0 MM pitch).

E-mail me for any questions with this. These are the only parts you will have to change now that you've done the caliper switch.

Here's my suspension and brake upgrade page so check for yourself. Click on first 2 Camaro links:

http://photos.yahoo.com/taramiller72