James911

Hi,

I have some problems with my breaks in my Impala 1970, all drums.
The wheels dont lock, even while break very hard, and I have a bad pressure. Afer some miles the breaks are becoming better, but they are still bad.
Meanwhile I have changed the master cylinder and have checked all wheel cylinder, none is leaking, all air is removed.

I heard that some cars have a proportion valve. What is it for?

I attached a pic. Is this the valve?
http://i303.photobucket.com/albums/n...k-P1050328.jpg
Could this cause my problems?
I could nor find it at rockauto or summit. Where can I buy it?

Thanks
James

leadfoot4

iTrader: (1)

Although it's been a LONG, LONG time since I worked on an Impala that old, I'm almost 99% positive that if you have drums all around, you don't have a proportioning valve. The proportioning valves were used on disc/drum cars. IIRC, the part in your picture is a safety device, in case one end of the car or other suffers a loss of line pressure, there's a "slider" valve in there that closes off that side of the brake system. The wire coming out of the piece triggers the dash board "idiot light" for the brake system.