GM 3905525 Metering Valve Disassembly and Rebuild

[sah62]

I've just completed disassembly and rebuild articles for the GM 3905525 metering valve made by Bendix for 1967 - 1969 GM vehicles. I've also got a new seal kit available that I'll post in the classifieds. Here's the disassembly article:

https://www.musclecarresearch.com/gm-3905525-autopsy

The rebuild article:

https://www.musclecarresearch.com/gm-3905525-rebuild

I don't yet have a reproduction of the Bendix rubber dust cap. I'm exploring my options to see if it can be done economically.

[Mike S]

 Perfect timing...
I am looking at mine and could not figure out how to extract the internals until I had seen your article.
As for a classified section, CRG has none specifically but if you post the info here I believe it will spread quickly as many here have the same setup and likely ageing conditions.
I'm certainly interested in what you have.

Thanks!
Mike

[sah62]

OK, then here's a link to the kit:

https://www.musclecarresearch.com/gm-metering-seal-kit-1

$9 plus shipping.

[Mike S]

 I placed my order plus the differential valve kit.
I was surprised how good the unit looks from the outside and the amount of brown crud on the inside.
Based on that I'm going to rebuild the brake pressure differential valve because I'm sure that has crud too.
The rest of my brake components are either new or rebuilt.

Thank you for the very well prepared instructions too!

Mike

[sah62]

Glad to help, Mike. I'll have your items in the mail on Tuesday when the USPS gets back to work.

[JohnZ]

Excellent work - thanks! 

[69Z28-RS]

Should be metering valve and brake switch unit be painted or 'natural' for factory original finish?   The bracket for the brake switch from my car appeared to have been 'dipped', and the metering valve bracket appeared to have been natural finish...  I went wild back in the 70's with my krylon and sprayed everything, so now between my overpaint and my 'old/bad' memory, I have no idea..      Any help appreciated as I cllean and reinstall these items.

Gary

[Mike S]

 The metering valve (or hold off valve) on my 67 had a parkerized finish like a firearm for the front cap. The body I am not sure of but all I can see on my survivor was surface oxidation so it was either unplated or any black paint applied back then wore off. The reproduction plating I have seen are wrong, at least for 67 from what I have seen so far.
More info can be found at: http://www.camaros.org/forum/index.php?topic=9970.0

As for the bracket I suspect it was likely dipped too and that would be 60% gloss black.

Mike

[sah62]

Has anyone ever seen one of these valves that didn't use a u-cup seal where the end of the spool valve rod comes through the valve body? I recently heard from someone who found such a valve on a '69 Malibu. The body wasn't machined for a seal - picture attached.

[sah62]

I now have a reproduction of the rubber dust cap that came with this valve:

https://www.musclecarresearch.com/cap-1

$10 plus shipping.

[m22mike]

Has anyone ever seen one of these valves that didn't use a u-cup seal where the end of the spool valve rod comes through the valve body? I recently heard from someone who found such a valve on a '69 Malibu. The body wasn't machined for a seal - picture attached.

No, not to date, have done 6 or 8 so far. If that is the case, as in your picture, I would suspect it may be machined to accommodate a "O" ring vs a cup seal.

Mike

[Spooky]

Great info! I will be doing mine shortly. Thanks!

Scott