Proportioning/Metering Valve

[tkoforpresident]

Okay... So I swapped a rear end from an lt1 into my 93 3.4 firebird.

I just got the brakes system bled completely at a shop to finish out the swap.

However, they told me that my proportioning vavle (or metering vavle) on the master cylinder is missing! Apparently the wiring is there for it but the valve itself isnt?

They suggested that it might be an aftermarket master cylinder (doubtful) and that i need to get a valve on there asap.

But I never touched that part of the brakes system and I've owned the car for almost 4 years.

I've heard some things thrown around before about this "proportioning valve" but never needed to read into it more.

What's going on here?

[tkoforpresident]

Re: Proportioning/Metering Valve

got the car back from the shop this morning and the BRAKE light is now on and the brake pedal is still way too soft. They bled the whole system and put new bleeder screws in up front because they were stripped out. Why isn't my brake system working right?? I think i might just need to take it to a competent auto shop... i explained to him that the proportioning vavle was INSIDE the MC and he started, then proceeded to show me a "wire" that was for the missing vavle and it ended up being my old alarm system wire that i had cut a long time ago...

[Bird_Of_Prey]

Re: Proportioning/Metering Valve

lol, I was reading your first post thinking the proportioning was controlled by the master cylinder, and these guys are idiots. Your second post confirmed that. By the sound of it, I wouldn't let them work on my lawnmower. Why not just DIY?

[Slowside]

Re: Proportioning/Metering Valve

people tryin to scam

[ssms5411]

Re: Proportioning/Metering Valve

lol, I was reading your first post thinking the proportioning was controlled by the master cylinder, and these guys are idiots. Your second post confirmed that. By the sound of it, I wouldn't let them work on my lawnmower. Why not just DIY?

X2, there your problem. I ordered a valve so I can adjust my rear brakes also have a line lock to install, just waiting for the proportioning valve to come in. It didn't give me the size of the line , but you can always order or make your own brake line to run to it ot fit it to work.

[LETZRIDE]

Re: Proportioning/Metering Valve

prop valve is only needed if you have deleted the ABS...did you delete abs? they probably didnt bleed the abs block if you didnt.

The red BRAKE light that comes on, comes on for 2 reasons.

1) your parking brake is up.

2) Your brakes are not functioning properly... I believe there is a sensor that monitors the brake pressure to each side. They should be the three connectors on top of the abs unit if you have it. Now, don't quote me on this as I am still trying to research so I can tap into the right wires to get my light off (I dont have a brake problem, but I deleted abs and the sensors are not longer hooked up) but 1 sensor should be for front left, 1 for front right, and one for the rear brake pressure...if any of these are out of wack or there is not enough pressure (I.e a leak) then that red BRAKE light will be on...

[tkoforpresident]

Re: Proportioning/Metering Valve

yup, i get the feeling that they didn't bleed the ABS properly.

[Blizzard242]

Re: Proportioning/Metering Valve

Yeah, I read somewhere the ABS valves have to be cycled via the computer or some type of diagnostics equipment which I'm assuming is run through the OBD port.

[Mogobs30th]

Re: Proportioning/Metering Valve

Yeah, I read somewhere the ABS valves have to be cycled via the computer or some type of diagnostics equipment which I'm assuming is run through the OBD port.

Technically yes, there is an option in most high end diagnostic tools to do this.

[tkoforpresident]

Re: Proportioning/Metering Valve

i would have bled the ABS myself but i heard there is a special tool to do it. (tech 2?) So i did the brakes as best i could.

The car is now at a good shop.. it might take longer, but it will be done right.

Brakes are NOT my cup o tea.

[Bandit127]

Re: Proportioning/Metering Valve

I don't believe that you HAVE to use a Tech 2 or something like the Snap-On Veros to bleed the brakes (infact, the only scan tool I can use on my 94 3.4 is the Tech 2). OnDemand5.com says theres a bleeding method without having to use a computer tool.

Its like 1 RR wheel 2 LR wheel 3 "port 1 ABS" 4 "port 2 ABS" etc etc with 11 or 12 steps total. I shall swing by the shop tomorrow and bring back some goodies. :)

[tkoforpresident]

Re: Proportioning/Metering Valve

brakes are nice and tight now!



plus they put on a new tie rod and gave it a NYS inspection for like ~ 120$ !!!



Great deal imo.



But as soon as i started driving home i realized the speedomoter wasn't working =(



It was working when i drove it in, I wonder what could have happened?



something the shop did? or just bad luck?

[LETZRIDE]

Re: Proportioning/Metering Valve

I know for the 3.8 when I unistalled the abs, I lost my speedo only when I put the car in neutral...so check your connections on the abs...make sure everything is snapped in...

[tkoforpresident]

Re: Proportioning/Metering Valve

oddly enough... the speedo kind of fixed itself.

I'm VERY curious as to how THAT would happen.