Brake proportioning valve recomendation

[GabeRoc]

I almost have my '73 project up and running. I was test driving around the subdivision and one of the lines rubbed up against a half-shaft and put a hole in it. As a result I lost all hydraulic braking (Three cheers for a working hand brake!). I knew that there had been some changes to the braking system, the front has a Toyota conversion and the rear has ZX disks, but I did not know they had gutted the proportioning valve. I have searched and looked through several threads trying to find a recommendation for a proportioning valve and haven't had much luck.

 

This is just going to be a street driven car, so I don't need a racing set up, but losing brakes is something I don't want to do again.

 

So, recommended set up? new master cylinder? proportioning valve? if a proportioning valve is the answer, one-in / one-out or two-in/two-out? What am I forgetting to ask?

 

Many thanks,

 

-Gabe

[Nigel]

When will people learn!? Proportioning valves on '73 and later Z should not be gutted! These proportioning valves use brake pressure going to the front right caliper to modulate pressure to the rear brakes. Gutting the valve ties the front and rear brake circuits together, which, as you discovered, defeats the purpose of having separate circuits. You need to remove the OEM valve from the firewall, splice the gap in the brake line going to the front right caliper, and splice the gap in the brake line going to the rear of car. Then, install an adjustable valve somewhere in line with the rear brakes. Wilwood, SSBC, Titlon and I'm sure a few others all make adjustable proportioning valves. They all work pretty much the same. Just don't buy some Chinese made crap. There is definitely information on Hybridz regarding installation...

 

http://forums.hybridz.org/index.php/topic/89547-how-and-where-to-install-the-adjustable-proportioning-valve/page__p__850112__hl__%2Bproportioning+%2Bvalve__fromsearch__1?do=findComment&comment=850112

 

 

Nigel

'73 240ZT

[GabeRoc]

I would have been really angry when I figured out what was going on, but I was too thankful that no one got hurt and that no real damage was done. I suppose I shouldn't have assumed that the stock valve was working. Something learned. :/

 

Thanks for the reply, I wanted to be sure that the tying the front brakes direct to the master cylinder and putting one of the one-in/one-out proportioning valves in the rear line was the correct solution. I am pretty comfortable with the installation.

 

have a good one.

 

-Gabe

[xShodaimex]

Hey Gabe I just ordered this prop valve the other day. Another member [crazyoctopus] has this in his set up I believe. There are tons about prop valves on this hybrid. Here's the link to the prop valve.

 

CLICK ME!

Edited September 13, 2010 by xShodaimex