C3 Proportioning Valve
Thread Starter
Burning Brakes
Joined: Jun 2000
Posts: 951
Likes: 0
From: NW Burbs IL
C3 Proportioning Valve
You guy are always there for my dumb questions. 
Here's another one.
I need a new brake proportioning valve for my '81, so I did a quick search of all the usual suspects and found a pretty large price disparity of what looks like the exact same part. Can anyone tell me with any confidence if these parts are indeed identical, or if one might be of higher quality, or a better manufacturer?
Ecklers:
Price: $119.99
http://www.ecklerscorvette.com/corve...1978-1983.html
(By the way, I love how the link lists the part going through the Corvette year 1983. That alone should disqualify Ecklers from my choices.)
Zip:
Price: $79.95
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={52583c3d-56a2-4ded-a316-5ef7df005d01}&gid={05a116b1-42db-4983-9684-37de2c7c8e84}&GroupName=Proportioning+Va lves&pname=78-82+Proportioning+Valve&Referer=&Alias=&p tct=SGR-SR&CTitle=&
Parts look identical, but looks can be deceiving. It also appears that one part might be of a slightly different material, but again that might just be from different picture quality, or the angle of the shot. Any help is greatly appreciated!! Thanks!
Here's another one.I need a new brake proportioning valve for my '81, so I did a quick search of all the usual suspects and found a pretty large price disparity of what looks like the exact same part. Can anyone tell me with any confidence if these parts are indeed identical, or if one might be of higher quality, or a better manufacturer?
Ecklers:
Price: $119.99
http://www.ecklerscorvette.com/corve...1978-1983.html
(By the way, I love how the link lists the part going through the Corvette year 1983. That alone should disqualify Ecklers from my choices.
)Zip:
Price: $79.95
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={52583c3d-56a2-4ded-a316-5ef7df005d01}&gid={05a116b1-42db-4983-9684-37de2c7c8e84}&GroupName=Proportioning+Va lves&pname=78-82+Proportioning+Valve&Referer=&Alias=&p tct=SGR-SR&CTitle=&
Parts look identical, but looks can be deceiving. It also appears that one part might be of a slightly different material, but again that might just be from different picture quality, or the angle of the shot. Any help is greatly appreciated!! Thanks!
Thread Starter
Burning Brakes
Joined: Jun 2000
Posts: 951
Likes: 0
From: NW Burbs IL
Thanks Mike.
I was having major braking issues, replaced the master, bled the brakes twice, but was still having soft braking issues. Took it to my trusted mechanic who did a check of the system. I had a calliper I suspected was leaking so I bought a new one, but couldn't get one of the bolts out, so I had him replace it and he power bled the system. He said that braking was still not what it should be and the brake light wouldn't go off. He tried getting the existing valve to work, but he said sometimes they go bad. I can't remember exactly how he explained it, but something about the valve getting stuck. Anyway, he said that the local parts places didn't carry the part, so he'd be willing to replace it if I could get the part. Zip was the most "reasonably" priced.
Any other opinions on what the difference might be between these two parts? I'll try to call both companies, but figured I'd try the real experts first.
I was having major braking issues, replaced the master, bled the brakes twice, but was still having soft braking issues. Took it to my trusted mechanic who did a check of the system. I had a calliper I suspected was leaking so I bought a new one, but couldn't get one of the bolts out, so I had him replace it and he power bled the system. He said that braking was still not what it should be and the brake light wouldn't go off. He tried getting the existing valve to work, but he said sometimes they go bad. I can't remember exactly how he explained it, but something about the valve getting stuck. Anyway, he said that the local parts places didn't carry the part, so he'd be willing to replace it if I could get the part. Zip was the most "reasonably" priced.
Any other opinions on what the difference might be between these two parts? I'll try to call both companies, but figured I'd try the real experts first.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If the light is on, then the differential spool is blocking one system and the brakes won't operate properly. You really can't tell any more until the valve is centered.
You should be able to remove the valve assembly, take it apart, clean the parts, center the spool and test while you're at it. I've done it without replacing the orings.
I doubt there is any performance difference in any of the valves you mentioned.
You should be able to remove the valve assembly, take it apart, clean the parts, center the spool and test while you're at it. I've done it without replacing the orings.
I doubt there is any performance difference in any of the valves you mentioned.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
What's the finish on these p valves? Not necessarily the replacements but the originals. Or, is it machined from a solid block of alloy?
Also on the topics of brakes, had the 78 on the lift and noticed what appeared to be brake fluid had accumulated on the bottom of the brake booster. I can only imagine that fluid has begun to leak from the rear m/c seal and finding its way to the bottom of the booster. Any ideas? Not bad but obviously noticeable.
Also on the topics of brakes, had the 78 on the lift and noticed what appeared to be brake fluid had accumulated on the bottom of the brake booster. I can only imagine that fluid has begun to leak from the rear m/c seal and finding its way to the bottom of the booster. Any ideas? Not bad but obviously noticeable.
Last edited by hunt4cleanair; Aug 17, 2011 at 04:31 AM.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
What's the finish on these p valves? Not necessarily the replacements but the originals. Or, is it machined from a solid block of alloy?
Also on the topics of brakes, had the 78 on the lift and noticed what appeared to be brake fluid had accumulated on the bottom of the brake booster. I can only imagine that fluid has begun to leak from the rear m/c seal and finding its way to the bottom of the booster. Any ideas? Not bad but obviously noticeable.
Also on the topics of brakes, had the 78 on the lift and noticed what appeared to be brake fluid had accumulated on the bottom of the brake booster. I can only imagine that fluid has begun to leak from the rear m/c seal and finding its way to the bottom of the booster. Any ideas? Not bad but obviously noticeable.
Yes, the the master is leaking, and to make it worse, it will drip onto the steering column and rust the lower bearing, shaft etc, making it impossible to remove without destruction.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If you can find the original part number on the prop valve,go to the truck parts dept at your local chevy dealer and see if they have it. Years ago I used to buy that part for 1/2 in the truck dept than I could in the car dept.
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Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
Supporting Vendor
Joined: Mar 2008
Posts: 576
Likes: 3
From: Muskegon MI
They all come from the same place. I've got them for $75.00 if you are still looking.
You guy are always there for my dumb questions. Here's another one.
I need a new brake proportioning valve for my '81, so I did a quick search of all the usual suspects and found a pretty large price disparity of what looks like the exact same part. Can anyone tell me with any confidence if these parts are indeed identical, or if one might be of higher quality, or a better manufacturer?
Ecklers:
Price: $119.99
http://www.ecklerscorvette.com/corve...1978-1983.html
(By the way, I love how the link lists the part going through the Corvette year 1983. That alone should disqualify Ecklers from my choices.)
Zip:
Price: $79.95
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={52583c3d-56a2-4ded-a316-5ef7df005d01}&gid={05a116b1-42db-4983-9684-37de2c7c8e84}&GroupName=Proportioning+Va lves&pname=78-82+Proportioning+Valve&Referer=&Alias=&p tct=SGR-SR&CTitle=&
Parts look identical, but looks can be deceiving. It also appears that one part might be of a slightly different material, but again that might just be from different picture quality, or the angle of the shot. Any help is greatly appreciated!! Thanks!
Here's another one.I need a new brake proportioning valve for my '81, so I did a quick search of all the usual suspects and found a pretty large price disparity of what looks like the exact same part. Can anyone tell me with any confidence if these parts are indeed identical, or if one might be of higher quality, or a better manufacturer?
Ecklers:
Price: $119.99
http://www.ecklerscorvette.com/corve...1978-1983.html
(By the way, I love how the link lists the part going through the Corvette year 1983. That alone should disqualify Ecklers from my choices.
)Zip:
Price: $79.95
http://www.zip-corvette.com/ProductDetails/ProductDetails.aspx?pid={52583c3d-56a2-4ded-a316-5ef7df005d01}&gid={05a116b1-42db-4983-9684-37de2c7c8e84}&GroupName=Proportioning+Va lves&pname=78-82+Proportioning+Valve&Referer=&Alias=&p tct=SGR-SR&CTitle=&
Parts look identical, but looks can be deceiving. It also appears that one part might be of a slightly different material, but again that might just be from different picture quality, or the angle of the shot. Any help is greatly appreciated!! Thanks!
