Hold off/prop valve question.

[DaneBisel]

I am in the process of converting my roadrunner from drums to front disc/ rear drums. They are manual brakes. I Just bought a prop valve and hold off valve from inline tube. They could not tell me how to install it or offer any suggestions. I have a metering block now that is along the frame, under the master cylinder. My question is: how the hell does this thing plumb up? Prop valve looks pretty self explanatory but hold off valve (3 port) is attached to the prop valve and not marked. Any help or tips would be much appreciated. I cant post pics but if you pm me than I will email them to you. Thanks a million!

 

[miller]

Kinda familar with what your talking about. Along those later years, they added in those devices.

Be best if you could get a service manual. Without being able to see the valve itself, the front brake feed line from the block, goes to the prop valve. The hold off valve...you could check if it's 'open' through all 3 ports. If so, one is feed line from the prop valve, the other 2, to each front brake.
SM would show the correct line set-up, and how the factory mounted it all.

 

[440+6]

This is the 1970 setup, don't know what year yours is.
You need a manual for your car, everything you need to know is in there.

 

[DaneBisel]

Thank you. I have a manual for it but it does not have that illustration. The confusion on my part comes from the fact that I am using a combination valve ( inline tube) and the metering block that bolts onto the combination valve. This eliminates the deprecate prop valve ( I think) and I don't know how to plumb it. Does it plumb the same as that pic minus the prop valve?

 

[miller]

What year car? Is it the metering valve your talking about?

Just glanced at my 69 manual. Set-up is different than the 70.

 

[440+6]

I have only used stock brake setups so I can't answer your question.
You should call inline tube, if they sold you the parts for a conversion they should know how they plumb together.

The one with 3 ports (top of diagram metering valve) splits off to the 2 front calipers from the safety tee.
The proportioning valve (hold off as some call it) goes to rear drums and once it reaches a certain pressure it stops the flow to the rear (hold off) and the front continue to work harder as you brake harder.

I know newer systems incorporated the proportioning valve into the safety switch tee, if you have that type of tee you don't need the separate valve going to the rear
You will also need the correct master cylinder, they are front drums are different than front disc.

I am not a brake genius or anything but I have done quite a few and they all work the same way, you just need the parts that are meant to work together.

 

[nm9stheham]

Can you list the Inline Tube PN's for the parts that you have?

 

[DaneBisel]

1969 . The part numbers are blk246 and blk247. I called inline tube and they could not offer me any assistance. I am going to plumb it according to 440+6's diagram. I think it is spot on. I sent the pic to inline tube and they said it appears to be correct. They also stated that they will save the pic for future uses! Thanks for the assistance