What brand of proportioning valve did you install? I have a Wilwood in mine and it had directions with it on how to set it up.

Steve

 

Hi
Put all new brake stuff on this winter,MC under floor,new lines,residual valves and proportioning valve in rear line. Car has 4 wheel drums,195/60/14 tires front and 225/70/15 rear. the proportioning valve is wound all the way out. How do I go about adjusting it? Is there a certain number of turns to start out with? How do I know when its right?
thanks

Set the proportioning valve midway from full open to full closed as a starting point.

Drive the car up to around 35 MPH and apply the brakes hard. This is best done on a wet surface where there is absolutely no other traffic. Large empty parking lots work well. The wet surface enables the tires to actually lock up and slide and you can then observe what is happening better. Someone viewing from the side is even better.

What you are trying to achieve is for the front brakes to be applied just before the rear.

If the rear brakes are applied first the back end of the car will have a tendency to "swap ends". Not a good thing.

Adjust the proportioning valve as needed to achieve the above. Closing the valve yields full pressure to the rear and opening the valve will reduce the pressure.

 

I have used the ssbc and summit brand valves with good success. You want to have the vehicle on a soft surface(sand,loose gravel,ect.) and do a few stops to ensure that all 4 wheels lock up at the same time under hard braking. the loose surface saves your tires while you adjust this, That is all you can really accomplish with a proportioning valve. :thumbup:

 

The way to a proportioned brake system should start with the correct parts in the correct place to begin with. Not trying to repair or adjust an inadequate system.

If you are in to light reading, then the answer would be, go to the appropriate web site of the Company who made the proportioning valve and see their recommendations. You could just 'luck out' and find a happy compromise.

The better way to go is by doing a search on brakes and reading the articles that come up under the search button. See this site for some good information:
http://www.mpbrakes.com/. You'll be way further ahead then going across a parking lot at 35 mph and slamming the brakes on in a puddle of water.

 

The valve I have is from Speedway---It might have had instructions,but I've missplaced or lost them

 

The valve I have is from Speedway---It might have had instructions,but I've missplaced or lost them

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Call Speedway and ask them if they can make a copy of the instructions for you and either fax them or mail them. They are usually pretty good that way. Just explain to them that you lost the orginal instructions and you are trying to set the proportioning valve now that you have the system together.

Good Luck.

Steve

 

Here is an article concerning the installation and adjusting the adjustable proportioning valve.

Adjusting the proportional valve

 

Give a man an fast answer and he's gone. Give a man an article to read and he just may learn something.

Excellent article Frisco!

 

DO NOT do your testing on a wet or loose surface unless that is all you will be driving on. When you have less traction you will have less weight transfer. If you set your rear brakes to lock up just after the front brakes on a reduced traction surface they will lock up BEFORE the rear brakes on dry asphalt.

 

Ditto, triaged!

locking up all four tires on a soft surface tells you nothing. The weight won't transfer to the front nearly as much as if you were on pavement, so you'll be setting it for the completely wrong surface. When you get it out on the pavement there will be too much in the back.

Get it close on soft surfaces, then tune it on the hard road. That way your first 15 lockups aren't destroying your tires; only the last 5.

 

Thanks for all the info,guys. I've been playing with it,don't have it exactly right yet,but getting close. Wife isn't too happy with all the skid marks on the driveway,might have to go to shopping center lot after they close

 

I turn my Summit unit (same as yours) all the way to the less brake side and start from there. You want to car to stop as fast as possible without the rear brakes from locking up. Do it on a regular street surface right on the top of the crown of the road.
The proportion valve has a "knee" pressure sensor built into it. It applies full pressure unless it senses high pressure coming from the master, like during a panic stop. Then it limits the rear brake pressure to keep the rear brakes from locking up during a panic stop.
I always wanted to try one on a four wheel drum brake car. My car is disc/drum.
A little tip with drum brakes is to remove all the self adjusters and manually adjust the brakes. Adjust the brakes all the way tight then back off until it moves with a little drag. Its more work but yields a more unified braking system with less drag.

 

I know what U mean,I have manual adjusters on the rear and self adjusters on front---I always know where my rears are adjusted,but always wonder if the front ones are doing their job