proportioning valve adjustment

That would be 3/4" of thread showing past the jamb nut.

and for adjusting:

I believe threading the adjuster OUT decreases the pressure available to the rear brakes.

Z. Ray

Well we are now into the horrible rainy cold weather so I have tackled one of the jobs I have been putting off - Brake proportioning valve.

I wanted to find out whether I had early or late internals so I could get a seal kit and also what the internal condition was.

If it will help anyone my 13th April 1965 car has the later style type A piston to go with the type A KIT 2B091-1BK (NPD NUMBER).

The internal condition was quite good, only one small pitt on the larger diameter bore. The piston was stuck fast at the smaller end beyond the seal but came out ok. It is all cleaned up now and refitted with the old seals. I stood on the pedal hard for about 10 mins and no leaks, but will keep a VERY careful eye on it, will also order a new seal kit.

BTW I had 0.700" of thread sticking out beyond the nut.

Edited by - cobraboy on 11/13/2009 12:14:28

Cobraboy,

As you said the date code on the end plate determines whick seal kit

you need. My 65 Shelby built at San Jose the first week of May, 1965 has a valve dated 39-5, i.e. day 39 of 1965 and I believe it has the one piece plunger while my friend's 66 Shelby built second week in Jan.1966 I believe has the two piece. If I don't recall wrong, the size on one of the seals is different in size. Also, I can have reversed the different types above A and B. Exactly 11 treads are visable outside the nut on

39-5.

/Bo

Bo

I got the info on the valve from http://www.stangerssite.com.

However there is a decrepancy between what kit is listed on that site for the NPD part number and what NPD list, they are saying the opposite to each other.

I have emailed stangersite asking which kit is needed for a valve that has a one piece piston - either early or late.

Will post feed back when I get it

Mark

Edited by - cobraboy on 11/13/2009 13:50:32

Cobraboy,

They have reversed the information on their site.

To be sure to get the correct one I bought both types

and my friend in Sweden rebuilt my valve with one of them and his (6S923) with the other.

/Bo

Bo

Sorry to be a dummy which NPD kit do I need for a one piece piston - early or late ?

Thanks

Sorry, but I don't remember. If I were you I would buy both

to be sure. They don't cost that much and you know you get what you need.

/Bo

Ok, I now have my NPD kit 2B091 - 1BK late type seal kit and it is compatable with my valve. My cars scheduled build date is 13th April 1965.

BTW the number on the end cap is F-278.

Hope this is of help to someone.