In need o fdisc brake advice

In need disc brake advice

Hey guys

I need some help.

A lil back ground.

I installed Wilwood front brakes(4 piston) and Wilwood rear brakes (4 piston) on my 73 Saty.

The stopping was only about marginal. I installed a new master cylinder and power brake booster. Oddly it went to almost no brake pressure at all.

I added a dial proportioning valve to the rear and adjusted the rear to very little pressure.

This brought the brakes back to simply marginal again. Poor pedal feel and seems to build better pressure if I pump the pedal first.

I have the master cylinder about 3/4 or so full. Im think I may need to add a lil more fluid and recheck.

When I bleed the brakes I have more pressure at the back than the front.

Any suggestions? Should I add a replacement front proportioning valve.

Thanks in Advance

Richie

I'm thinking you should try another "BLEED"
Have you tried this first?

you might call willwood and make sure your master moves the correct amount of fluid for your set up.also,check to make sure your bleeder screws are on the tops of the calipers,otherwise you are trapping air in there.

. Link to willwood tips on brakes...

http://www.wilwood.com/TechTip/TechTip.aspx

Thanks for the replies. Ill do the bleed again.

The screws are on top and bottom so I bleed all 8.

Thanks. The links much appreciated!

Richie

Just got off the phone with Wilwood, thanks again for the link, I hadnt even thought to contact them, they suggested eliminating the factory proportioning valve...anyone else used thsi approach??

RICHIES ARMOR said:

Just got off the phone with Wilwood, thanks again for the link, I hadnt even thought to contact them, they suggested eliminating the factory proportioning valve...anyone else used thsi approach??

Click to expand...

I would agree with that. The factory proportioning valve is non adjustable and utilizes a certain sized orifice in the block to supply a controlled pressure at load to the rear brakes. It was engineered to work with your factory brakes, not Wilwoods. I'm guessing your car had front factory disc and rear drum? If so, it's really going to be off now you have disc in the back. If your car came with drum/drum, that original block under your hood isn't even a proportioning valve, it's a distribution block that just routes fluid to each wheel from a centralized junction. Being you have an aftermarket kit all the way around, you would need a variable control (ie adjustable proportioning valve) to compensate the difference in braking pressure needed between front and rear (about 60% Bias to the front). Wilwood makes a combination proportioning/distribution block that would work, or if you had a drum/drum car with that factory distribution block you could plumb in a variable control proportioning valve in your line to the rear brakes. I would also ask Wilwood if you need an in-line residual valve for the rears with your current set up.

Wilwood Combination prop valve



Wilwood prop valve

Also with 4 wheel disc's, the master has to be bigger to move the volume required for the disc's......so what size are ya runnin'?

Thanks for info propwash.

I just replaced the stock master cylinder with a replacement/remanufactured unit. Ill ahve to research the size.

Richie

Hey no sweat....I don't want to start sweating it if I ever see you rolling up in your mopar behind me..lol

Propwash said:

Hey no sweat....I don't want to start sweating it if I ever see you rolling up in your mopar behind me..lol

Click to expand...

Yeah no kidding!!

I ordered the Wilwood proportioning valve. I may step up to their master cylinder as well.

Thanks

Richie