So I've replaced my brakes, front and rear. New rotors, master cylinder, etc. The brakes are much better, but the brake light is still on, and I get a loud CLUNK that sounds and feels like it's coming from the driver's side front when I step on the brake, but not all the time. It seems more pronounced if I'm driving slow.
The only culprit I have left is the proportioning valve. This comes off of the brake lines below the master cylinder. Go figure, I can't find a new one anywhere. LMC has them for $439 which is just plain ridiculous. I have found them on Ebay but they are made of brass, but they are only $70.00. I hate to waste money on a used one from a junkyard with no guarantees. So has anyone tried one of these brass brake proportioning valves?
Second part of this is, how hard is it to replace. It looks pretty simple, as it is just hanging there from the brake lines. I replaced the master cylinder easy enough and bench bled it with no problems. Is there any prep work like that with the valve? Thanks for the help! This is on my '85 EB.

 

Get a Haynes, i'm not 100% sure, but i think i recall reading you could calibrate that valve.

 

I've got the haynes and it doesn't even mention the valve anywhere for my truck. I think it mentions it as being part of the master cylinder in a different year. I honestly don't like this Hayne's manual at all, it's not been very useful. I think I'm going to go to O'Reilly's tomorrow and buy a Chilton's. But you think it may be adjustable? That's a positive thing. It isn't leaking so maybe it's something simple with it.

 

I too am thinking it's something simple, i do recall reading something about that, check the info on my generation's model, because i recall it was stated there that some of the older models could be calibrated/adjusted.