Brake Valve on the side sub frame for a 69 camaro

[enio45]

Im cleaning out and rebuilding the brakes on a friends 69 Z 28 and was wondering if anyone has taken the brake valve apart. I was considering doing this as part of the cleaning process etc.....

Does the nut just unscrew - anyting inside i need to worry about?

Thanks for the advise

[sah62]

Does it look like the valve described on my web site?

http://www.musclecarresearch.com/197...-valve-autopsy

If so, there are three o-ring seals in the valve that can degrade over time. They're made of a special EPDM rubber compound that's compatible with brake fluid. The o-rings you can pick up at your local parts store aren't a good replacement because they're usually made of nitrile/buna-n rubber that isn't compatible with brake fluid.

I'm currently looking at the possibility of producing a rebuild kit for valves like the one pictured on my site. I'd appreciate your feedback in this thread if you think it's a worthwhile project:

https://www.yenko.net/ubbthreads/ubbt...;Number=453720

[enio45]

Scott - i have that valve on my camaro as well - however in addition to that one there is another valve down on the subframe under the driver seat (called the hold off valve) that has one inlet and one outlet. There is a large nut on it that gives access to "something" inside.

Here is the ebay pic
http://cgi.ebay.com/ebaymotors/67-68...item2eb597320e

let me know what you think for this valve to rebuild?

[sah62]

The fact that it can be opened up means it might be rebuildable. It all depends on what's wrong and what's inside. Is yours not working? Would you be willing to take yours apart and share pictures or send it to me so I could take a look?

[mockingbird812]

Hold Off Valve (referenced above)

[m22mike]

Sam and Eddie
If I may correct your nomenclature just a bit.
The round valve under the master cylinder is the "hold of valve" It holds off the front disc brakes untill around 40 psi. and allows the rear brakes to come in first to prevent nose dive.
The other valve on the frame is the rear brake pressue regulating valve.
Keep in mind Sam that all the companies out there selling these two valve's have no idea what there called. Like the link you posted.
Both these valves have been discussed at length over at CGR, and explained by John Z in detail.
Now...carry on

[169indy]

Can I send someone a image of one apart for them to post.

Jim W

[mockingbird812]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 169indy</div><div class="ubbcode-body">Can I send someone a image of one apart for them to post.

Jim W </div></div>


Jim forwarded these photos and description to me via email:

<span style="font-weight: bold"><span style="font-style: italic">&quot;Hi there this is 169indy (Jim Weaver) of Bremerton.
I took apart my vavle on my 69 pace car.
Here a couple of pics. The valve was full of gunk (Tech for CRAP)
The disassy was not very hard and I just cleaned the parts up and relubed with DOT5 and reinstalled being careful with the softgoods.

2 pics

I included another pic I lifted from CRG
NOTE also included is a pic of the one near the booster (photo credit JOHNZ)


Thanks for posting them

Jim&quot;</span></span>

[sah62]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m22mike</div><div class="ubbcode-body">Both these valves have been discussed at length over at CGR, and explained by John Z in detail.</div></div>

Wow, as I'm reading through eBay ads I see what you mean about the confusing nomenclature. Lots of people don't seem to know the difference between the pressure differential, proportioning, and metering/hold-off valves. I'll have to add that info to my web site.

[mockingbird812]

Aye-aye Mikey....thanks for the correction. Good to know. (are you saying that you can't believe everything you read?!!!!!!!!!!!)