gmclist@list.gmcnet.org

GMC Motorhome Discussion List

View all threads

Re: Problem with brass body proportioning valve

TP
Thomas Pryor
Thu, Jul 29, 2021 7:40 PM

Well again Thanks to Dave Lenzi, he created the need for more knowledge on
what happened with the replacement Brass combination valve for our
coaches.

In a previous life I worked for Kelsey Hayes ABS group as quality "Grunt"
Foundation brakes knowledge was available to me. So I decided to swim
upstream and found out that a brass replacement valve for our coaches WAS
DEVELOPED and put on an engineering drawing.  The Code name was PVMH, who
knew!
That engineering drawing resurfaced in China and Jim Kanamota has been
provided with the manufacturer name /contact info. He is negotiating a MOQ
(Minimum Order Quantity) .  I have been assured that all valves will be
function tested before shipment from the China factory.

MY FINAL THOUGHTS;

  1. You can modify the PV2 valve to eliminate the pressure limiting to the
    rear brakes. Your option, your risk!
  2. If you have the original KH86702 Cast Iron Valve.( no rear pressure
    reduction)  Flush the brake fluid per the GMC maintenance manual, It may
    look ugly on the outside and perform all required tasks admirably.
  3. If you ever have to replace the Combination valve make sure it is a
    PVMH.

If you want to follow my investigative /archival information please see:
http://www.gmcmhphotos.com/photos/combination-valves/p68277-gm-valve-autopsy.html

--
Regards,

Tom Pryor
4188 Limerick Dr
Lake Wales, Fl 33859
Cell 248 470 9186

1977 23'B named "CASPER",  HARDLY ORIGINAL, (455 EFI) (Pwr. Drive)
(tailgate) (rear bunk beds)
(Webasto petrol boiler) (MB Elect fan clutch) (Brake reaction arms) BUT
STILL A WORK IN PROGRESS!

ReplyForward

Well again Thanks to Dave Lenzi, he created the need for more knowledge on what happened with the replacement Brass combination valve for our coaches. In a previous life I worked for Kelsey Hayes ABS group as quality "Grunt" Foundation brakes knowledge was available to me. So I decided to swim upstream and found out that a brass replacement valve for our coaches WAS DEVELOPED and put on an engineering drawing. The Code name was PVMH, who knew! That engineering drawing resurfaced in China and Jim Kanamota has been provided with the manufacturer name /contact info. He is negotiating a MOQ (Minimum Order Quantity) . I have been assured that all valves will be function tested before shipment from the China factory. MY FINAL THOUGHTS; 1. You can modify the PV2 valve to eliminate the pressure limiting to the rear brakes. Your option, your risk! 2. If you have the original KH86702 Cast Iron Valve.( no rear pressure reduction) Flush the brake fluid per the GMC maintenance manual, It may look ugly on the outside and perform all required tasks admirably. 3. If you ever have to replace the Combination valve make sure it is a PVMH. If you want to follow my investigative /archival information please see: http://www.gmcmhphotos.com/photos/combination-valves/p68277-gm-valve-autopsy.html -- Regards, Tom Pryor 4188 Limerick Dr Lake Wales, Fl 33859 Cell 248 470 9186 1977 23'B named "CASPER", HARDLY ORIGINAL, (455 EFI) (Pwr. Drive) (tailgate) (rear bunk beds) (Webasto petrol boiler) (MB Elect fan clutch) (Brake reaction arms) BUT STILL A WORK IN PROGRESS! ReplyForward
BM
Billy Massey
Thu, Jul 29, 2021 8:32 PM

Thanks for this news, Tom.  I'm so glad that there people constantly
working in the background for our safety.
Jim is to be commended for always having our backs.  I hope to be one of
the first adopters in support of his business.

bdub

On Thu, Jul 29, 2021, 2:40 PM Thomas Pryor tepryor@gmail.com wrote:

Well again Thanks to Dave Lenzi, he created the need for more knowledge on
what happened with the replacement Brass combination valve for our
coaches.

In a previous life I worked for Kelsey Hayes ABS group as quality "Grunt"
Foundation brakes knowledge was available to me. So I decided to swim
upstream and found out that a brass replacement valve for our coaches WAS
DEVELOPED and put on an engineering drawing.  The Code name was PVMH, who
knew!
That engineering drawing resurfaced in China and Jim Kanamota has been
provided with the manufacturer name /contact info. He is negotiating a MOQ
(Minimum Order Quantity) .  I have been assured that all valves will be
function tested before shipment from the China factory.

MY FINAL THOUGHTS;

  1. You can modify the PV2 valve to eliminate the pressure limiting to the
    rear brakes. Your option, your risk!
  2. If you have the original KH86702 Cast Iron Valve.( no rear pressure
    reduction)  Flush the brake fluid per the GMC maintenance manual, It may
    look ugly on the outside and perform all required tasks admirably.
  3. If you ever have to replace the Combination valve make sure it is a
    PVMH.

If you want to follow my investigative /archival information please see:

http://www.gmcmhphotos.com/photos/combination-valves/p68277-gm-valve-autopsy.html

--
Regards,

Tom Pryor
4188 Limerick Dr
Lake Wales, Fl 33859
Cell 248 470 9186

1977 23'B named "CASPER",  HARDLY ORIGINAL, (455 EFI) (Pwr. Drive)
(tailgate) (rear bunk beds)
(Webasto petrol boiler) (MB Elect fan clutch) (Brake reaction arms) BUT
STILL A WORK IN PROGRESS!

ReplyForward


GMCnet mailing list
Unsubscribe or Change List Options:

Thanks for this news, Tom. I'm so glad that there people constantly working in the background for our safety. Jim is to be commended for always having our backs. I hope to be one of the first adopters in support of his business. bdub On Thu, Jul 29, 2021, 2:40 PM Thomas Pryor <tepryor@gmail.com> wrote: > Well again Thanks to Dave Lenzi, he created the need for more knowledge on > what happened with the replacement Brass combination valve for our > coaches. > > In a previous life I worked for Kelsey Hayes ABS group as quality "Grunt" > Foundation brakes knowledge was available to me. So I decided to swim > upstream and found out that a brass replacement valve for our coaches WAS > DEVELOPED and put on an engineering drawing. The Code name was PVMH, who > knew! > That engineering drawing resurfaced in China and Jim Kanamota has been > provided with the manufacturer name /contact info. He is negotiating a MOQ > (Minimum Order Quantity) . I have been assured that all valves will be > function tested before shipment from the China factory. > > MY FINAL THOUGHTS; > 1. You can modify the PV2 valve to eliminate the pressure limiting to the > rear brakes. Your option, your risk! > 2. If you have the original KH86702 Cast Iron Valve.( no rear pressure > reduction) Flush the brake fluid per the GMC maintenance manual, It may > look ugly on the outside and perform all required tasks admirably. > 3. If you ever have to replace the Combination valve make sure it is a > PVMH. > > If you want to follow my investigative /archival information please see: > > http://www.gmcmhphotos.com/photos/combination-valves/p68277-gm-valve-autopsy.html > > -- > Regards, > > Tom Pryor > 4188 Limerick Dr > Lake Wales, Fl 33859 > Cell 248 470 9186 > > 1977 23'B named "CASPER", HARDLY ORIGINAL, (455 EFI) (Pwr. Drive) > (tailgate) (rear bunk beds) > (Webasto petrol boiler) (MB Elect fan clutch) (Brake reaction arms) BUT > STILL A WORK IN PROGRESS! > > ReplyForward > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
MC
Matt Colie
Thu, Jul 29, 2021 9:39 PM

If you have a PV2 valve and after reading Dave's article in Vintage Motorhome, you thing just gutting the back part of the valve sounds like a good
idea, sit down.  Have another drink and think again.  This would not be all that tough on the bench, in a vice and with the right tools and good
light...

I strongly suggest that you not consider doing it in place.  All I did was pull out the rubber plug.  That broke the pick tool I tried to use first.
I did have to bleed the brake system.  I have not test driven the coach yet.  Tests in place look real good.

When I have more data, I will broadcast it here.

The coach is back on the ground, but I have a serious amount of cleanup to do after the recent power outage.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

If you have a PV2 valve and after reading Dave's article in Vintage Motorhome, you thing just gutting the back part of the valve sounds like a good idea, sit down. Have another drink and think again. This would not be all that tough on the bench, in a vice and with the right tools and good light... I strongly suggest that you not consider doing it in place. All I did was pull out the rubber plug. That broke the pick tool I tried to use first. I did have to bleed the brake system. I have not test driven the coach yet. Tests in place look real good. When I have more data, I will broadcast it here. The coach is back on the ground, but I have a serious amount of cleanup to do after the recent power outage. Matt -- Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms SE Michigan - Near DTW - Twixt A2 and Detroit