I did a BW 9 bolt rear end swap with 1LE brakes and I beleive 3.27 or 3.42 gears.

My car is a 91 and the swap was from a 89. Still unable to get my brakes working due to the incorrect prop. valve.

I did a search on google for the correct valve which I think is this one here:

http://www.flynbye.com/catalog/i160.html

Was not able to find the valve anywhere else on the web and in stock.

Anywhere know some other alternatives? That's quite expensive and I was actually going to order it till I read that they are no longer taking orders on their main page.

Already tried the stiffer spring and it did not work. :/

 

you could always do away with the stock prop valve and go with an adjustable aftermarket one. that way you can dial it in just right. I also remember seeing one member around here who modified their stock one to be adjustable. something I may try to do myself as well if I can grab a spare at the local jy

 

Its been a while since I posted about my brakes, Till today I still have not been able to get them working correctly.

I have tried a few things with no success. Its a 91 f-bird that came stock with front disks and rear drums. I swapped in a 9 bolt 3.42 borg warner rear end that came stock with the 1LE brakes.

At first my rears did not lock at all, I ended following one of the prop. valve tricks and installed a harder spring... same issue, no rear brakes no matter how hard I would hold them down.

Got pretty upset so I then bought a 1 3/4 spring that was much harder than the first one. Finally I was albe to get my rears to lock... although not the way that they should.
Now they only lock under full brake pedal pressure... they slow down a bit in between but this is all testing when in drive and on jacks.

Just today I received two brand new brake calipers for the rear and installed new brake lines as well, I have the same issue, the rears only lock under full brake pedal pressure.

Seems like the E brake is working although I need to adjust the small allen bolt to get them to lock, as they only slow down to a crawl when I pull the e brake.
I feel as though I have two options left.

1. Install my own adjustable valve which I would really like to avoid.
OR
2. Purchase the correct prop. valve below:
http://www.flynbye.com/catalog/i160.html

I would like to go with the second option yet my main concern is that I have seen posts in which they show that the two valves are almost identical... after installing a 1 3/4 inch spring which was extremely difficult to put in without threading the plug... I'm a bit skeptical as to whether the correct valve will actually fix the issue.

 

Apparently the bias is increased from disc/drum to disc/standard disc to disc/1LE, so for best braking performance, the correct valve for your application is the best bet--that or an adjustable. No issues for me with my conversion.

JamesC

 

Ok, I will be purchasing the correct valve. Is there anyway to obtain the valve from anywhere other than flynbye.com ? Seems like every time I call either a lady answers who takes my message or no one answers at all.

 

GMPartsDirect, GM 10164112.

JamesC

 

LOL

*10164112
Eng Asm
VALVE ASM
1
$65.44
1
$65.44
$61.62
$0.00
$65.44
Shipping & Processing & Handling:
$416.69
Total:
$482.13

I think I'm going to have to keep trying to get in contact with Ed Miller lol...

 

Well... I did find this one as well but the site looks a big iffy, no pic, no details...

http://www.gmpartsgiant.com/parts/gm...-10164112.html

 

Check at the bottom of the page of company info. Looks legit. The shipping/handing to me was only $12 or so from them--versus the $416 from GMPartsDirect (how can that be correct?).

JamesC

 

"Order Succeeded
Thank you for shopping at gmpartsgiant.com. Your order will be processed and shipped in about 3-5 days."

*Fingers Crossed*

I'll advise of results when I get it.

Thanks!

 

I really dont think this is going to make a difference for you. IIRC the only difference is the spring in the assembly on the later cars. I dont think the outcome is going to change, you will need to get an adjustable or a stiffer spring.

Or your master cylinder may not be correct and you are not getting the proper pressure for your setup

 

The master won't be an issue. 89-91 shows the same Cylinder, Brk Master GM 18014286. Earlier years show different masters for J50 and J65. GM, however, pretty much made them interchangeable (All have the 'quick take up' master):

https://www.thirdgen.org/forums/susp...fferences.html

The valves, of course, are different.

JamesC

 

What also makes me believe that the valves are different is that FlynBye.com has this modifiication purchase: (Or had lol)

http://www.flynbye.com/catalog/i160.html

 

Thats to modify the current disk/drum valve... I dont think he would make ya ship the entire unit just to install a spring... or I hope not.

 

Well the only difference between the threads for the different years is the bias, I have taken a few of these apart and functionally all of the are the same internally with the spring being the only real difference. If he needs more rear line pressure I dont think that a different factory valve is going to make much of a difference.

I meant he may want to consider a different master with a smaller bore (I think?) to get more line pressure out of the rears, or just put in something adjustable.

 

I find the info in Pat Hall's post (#9) revealing where the matter of bias and the 1LE valve is concerned:

https://www.thirdgen.org/forums/tran...ve-91-z28.html

EDIT: For what it's worth, I converted to the 1LE set-up a number of years ago (using the 1LE valve) and have never experienced any issues.

JamesC

 

Well... I guess that didnt work lol

"Hello Marco

Thank you for ordering parts with us.

We are writing to inform you that order 37138 has been voided. Your order has been voided because of the following reason: The ordered part(s) have been discontinued by the manufacturer and no longer available from our warehouses.

If you have any question or believe this is an error, please contact us at service@gmpartsgiant.com for additional assistance.

Regards,
Customer Services
Gmpartsgiant.com"

Now what lol I dont want to install an adjustable... just seems like too much of a hassle but might have to be my only option...

 

I have the same problem. Took my 10 bolt drum out of my 92z. Threw in a 88 9 bolt disc. Cannot get them to work and i put the porp valve in from the 88. Clueless on what to do.

 

Curious. Since the tube nut threads on the 88 are different from the 92 (M1.0 vs M1.5), how'd you mate lines with the valve?

JamesC

 

So... problem is fixed! ...
Installed a wilwood proportioning valve and my rear brakes now lock.

Hardest part of the install was flaring the 6mm rear end to prop. valve brake hose... or well may have not been so hard if I had known it was metric and not a standard line.

I broke my first flaring tool trying to get it to grab on, second tool was more heavy duty but the line kept slipping. Finally gave up and drove to a local brake shop with only my front brakes to have them flare it for me.

After measuring the line I was told it was a 6mm and they did not have the tools to flare it so I ended up finding a metric flaring set at autozone for rent. Finally got it flared with no leaks!

Only problem now is my brake booster still doesn't have quite enough vacuum. I have a cam with .477 lift and its really not too bad but it use to be much better with the stock engine. Any quick fixes for this?

 

do you have a pic or schematic to how you did the lines to the adj. prop valve?

 

I'll post a few in a bit.

 

Here they are

 

hey guys im in the process of doing a conversion right now.i did all the work at the rear of the car and i would love the same set up as napster134 has. napster can you tell me the fitting sizes on the tee you made up to twin together the fronts. i know i have metric fittings on my car cus the first brake lines i bought for rear were the wrong ones.thanks in advance!

 

The T is a 3/16ths female on all three.

There were 3 different sizes I believe.

The front brakes are all 3/16ths. Now the line coming from the rear-end of the car to the valve is a 6mm metric line.

And I have no idea what size is small one coming from the top of the master cylinder into the valve because I was not the one who flared it, the brake shop flared it for me since I was already there and it was a short line so I would have had trouble cutting it and flaring it myself. I am almost sure it is a 1/4 standard line since according to the brake shop they did not have the tools to flare metric.

Therefore if your car is stock and the same year as mine you would only need to worry about the 6mm metric line coming from the rear end to the valve. Almost sure that the rest are standard.

 

There is a tech article on how to do this although it is not accurate (in regards to the size of the brake lines) for all thidgens since apparently my year has a metric line.

Here it is:

https://www.thirdgen.org/propvalve