pianiy

iTrader: (2)

Ok, before anybody jumps down my throat, I'm a big advocate on searching for answers first and I did that but came up with nothing.

I need to know which proportioning valve I have. It should be stock (I didn't change it).

91 Firebird
L03
non-1LE

The valve appears to be made of aluminum and has clean 90* machined edges. There are three diagnonal hatch marks, two above the outlets and one below what appears to be a pressure sensor all located on the passenger side. I cannot find a part number on it. I DID find these numbers/letters engraved on the driver's side of it though: MB 32 KH 0640. If anybody has a 1LE car or the 89+ 1LE proportioning valve could you please check this out and see what your's may say?

Both hardlines to the brakes exit out the bottom of the valve. There is nothing that I've read that can distinguish this stock valve I have from a 1LE valve. According the parts and illustration catalog for my vehicle I should have proportioning valve part number 10136839 (J41/J42) but should be looking for valve part number 10164112 (J65).

[b]NOTE: I have just upgraded to 1LE brakes and they work fine with the valve that I have now. I'm about to upgrade the rear (drum/open/2.73) to a disc/posi/3.23 rear out of a 92 GTA with the PBR brake setup and I need to know if I have the right proportioning valve.

There is only ONE master cylinder available for my year according to the parts and illustration catalog which leads me to believe that it doesn't matter what MC I have for any of these upgrades.

I took some pics of it tonight and I'll upload them when I get a chance.

Of course, I'd like hard concrete evidence like a part number but I cannot find one.

ebmiller88

iTrader: (7)

You've got a '91 year car, you're good to go. GM used the same prop valve on all brakes from '90 on up. Just to be sure, it should have an FX on the front. My '88 Iroc with the J65 (bad) disc setup had FY on the front of the valve, adn I had to change it.

Check my rebuild page for pics and such, they're almost at the end of the first link:

http://photos.yahoo.com/taramiller72

Have fun!!

Ed

pianiy

iTrader: (2)

That FX is on the master cylinder, there is nothing on the prop valve. And according to the parts and illustration catalog, there are two valves listed for my model year.

mystikkal_69

iTrader: (2)

172-2038 VALVE,BRK COMB
With CAST IRON BRK SYS(J41)^AL BRK SYS(J42) USED W/M1.5 TUBE NUT THREADS BROADCAST CODE MB<-----


172-2074 VALVE,BRK COMB
With 4-WHL DISC BRK(J65) USED W/M1.5 TUBE NUT THREADS BROADCAST CODE MC/MD<-----


broadcast codes are one way used to identify the combo valves. your MB is one. MC & MD are others.

as for which one is the correct one.......... i can't tell right off hand.

pianiy

iTrader: (2)

Here are the pictures:

ebmiller88

iTrader: (7)

Geez...

..pardon the brain fart Luke. I had M/C on the brain and didn't think of anything else.

Look here, hope this helps. I list both M/C and prop valve P/Ns in this old thread:

https://www.thirdgen.org/techbb2/sho...e&pagenumber=2

On page 2, I posted this:

OK, prop valves now.(All GM P/Ns FYI..)

82-85.....................14075706
82-83 RR Disc.............25511944
82-83 EXC RR Disc.........25515423
84-85 EXC RR Disc.........25517738
84 RR Disc................25517739
84-85 JE1.................25517740
85 RR Disc J65............25521985
86-88 J50.................14089495
86-87 JE1.................14089496
86-88 J65.................14089497
89 J50 2ND Design.........10136839
89 J65,1LE 2ND Design.....10136840
89 J65 EXC Y82,1LE 2ND Des.10136841
89 J50 1ST Des.............14089495
89 J65 EXC 20TH Ann Y82,1LE 1ST Des..14089497
90 J41,J42................10136839
90 J65,1LE................10136840
90 J65(EXC 1LE)...........10136841
91 Cast Iron Brk Sys J41
Alum Brk Sys J42.......10136839
91 J65 4 Wh. Disc ........10164112

Since you posted the car as a "L03, non-1LE", I'll assume you have the disc/drum setup stock. Regardless of that, here's the P/Ns concerning you:

91 Cast Iron Brk Sys J41
Alum Brk Sys J42.......10136839
91 J65 4 Wh. Disc ........10164112 (Doesn't list 1LE)

IMO, you should be running part number 10136840. I say that for 2 reasons: One, because it will be the 2nd design threads for the 90 and up years; and 2, that's the valve listed for the 90 1LE system. I don't understand the difference in part numbers 10136840 and 10164112. SInce they're the same rear disc system, I'd think they'd be the same, therefore there must be a difference in the front system, I.E. the calipers.

Maybe Andy can help us out a bit.


Ed

pianiy

iTrader: (2)

Thanks for the info Ed, but it still doesn't narrow it down really until I actually see something on my valve that distinguishes it. I'm one to not believe until I see, who wants to screw around with something as important as brakes anyway? :nono:

I think the best evidence so far is the broadcast numbers that mystikkal_69 posted which would mean that I have a J41/42 valve.

Does anybody know if there ARE part numbers engraved on the valves?

mystikkal_69

iTrader: (2)

from the info posted you do infact have a standard(J41/J42) disc/drum as presviously metioned. do you have the complete 1LE system or just the rear. if you do have the whole the system then 10136840 is the right choice. if you only have the rear then
10136841 is the right choice. 90-91 same difference.


90 J41, J42..........10136839 <--- (you have this one) broadcast MB
90 J65, 1LE..........10136840 <--- broadcast code MD
90 J65(EXC 1LE)...10136841 <--- broadcast code MC



if your looking for a used one then go by the broadcast code. if not go to gmpartsdirect.com (that's what i did) and type in the corresponding part# for your application. happy hunting.

pianiy

iTrader: (2)

Alright, there we go, thanks mystikkal_69 for that last bit of info... turns out they aren't available through gmpartsdirect anymore so I'm gonna have to start searching the yards.

I upgraded to 1LE and now I'm upgrading the rear so I'll need the one with broadcast code MD.

mystikkal_69

iTrader: (2)

try emailing them this acdelco part#. tell them to cross reference it for you. that will give the prop valve you need.

172-2074 VALVE,BRK COMB

With 4-WHL DISC BRK(J65)^PERF PKG(1LE) USED W/M1.5 TUBE NUT THREADS BROADCAST CODE MC/MD

pianiy

iTrader: (2)

Thats gonna be a problem as I've emailed them before with specific questions regarding parts I'm upgrading TO yet aren't found stock on my car. They have emailed me back asking for the VIN number of my car so they could get me the right parts - basically I'd need the VIN from a 90-92 1LE f-body to give them. They're just stubborn like that.

mystikkal_69

iTrader: (2)

hmm let me give it a try. i've never had that problem before . i'll get back with info.

mystikkal_69

iTrader: (2)

Andy is right about the prop valve you need. here is an excerpt of the email i recieved when i emailed them about the 172-2004 valve.

Thanks for your inquiry to www.gmpartsdirect.com.
Here are your part numbers you requested.

10164112 valve

pianiy

iTrader: (2)

Thanks man, I went ahead and ordered it last night