Update on my 75 GMC II

  • Please note, the forum recently had a problem with outbound emails for notifications, registrations, etc. A new email provider has been set up which should resolve all email issues. If you have any further trouble, please DM Christo or reach out via the Contact Us link in the website footer.

Bodie Miller

Member
Aug 21, 2025
61
43
18
We made the trip from the warehouse that was home to this coach for nearly 22 years to Oklahoma without a hitch, she purred like a kitten due to all the advice given on preparing her before actually starting and driving. We have nicknamed named her "Ellie" since the title says Eleganza on it. I recently completed all the chrome polishing and she looks amazing. We joined our local car club, Blast from past and everyone was extremely excited about Ellie the first time they had encountered a motorhome in the line up. We missed the Christmas parade of vehicles by a day but will be in the springfest with the car club. They have already decided Ellie will be one of the show stoppers in the parade and placed last in the lineup as the grand finale vehicle. I am attaching before and after photos of chrome and body and cerokote and chrome polish.
 
I sure will, looking forward to it and the rally in Louisiana. the first run was 286 miles from warehouse in Franklin, Tx. to Oklahoma home. I am still not real comfortable with the brakes, I have brakes I just want better. I am going to revisit that in the very near future.
 
I sure will, looking forward to it and the rally in Louisiana. the first run was 286 miles from warehouse in Franklin, Tx. to Oklahoma home. I am still not real comfortable with the brakes, I have brakes I just want better. I am going to revisit that in the very near future.
Like Larry said, Dave Lenzi is a HUGE asset to the GMC Motorhome community. He's part Master machinist, part wizard and totally a super nice guy. You'll want to give him your money and it'll make you a lot more comfortable knowing you've got the best brakes possible.

I'm really glad you're jumping into your GMC full on, and also really glad you'll be representing our GMCs. You haven't driven it much yet but you'll get a kick out of pulling into a gas station and people just HAVE to talk to you about it! I had one guy running from 50 yards away yell at me to wait as I was pulling out, another time I'm talking to one guy, another steps forward and starts listening, and then a third guy gets on line to ask questions! It's a hoot.
 
I sure will, looking forward to it and the rally in Louisiana. the first run was 286 miles from warehouse in Franklin, Tx. to Oklahoma home. I am still not real comfortable with the brakes, I have brakes I just want better. I am going to revisit that in the very near future.
Have you met Ty Hardiman in Norman OK? He's Mr. GMC mid-America.
 
I sure will, looking forward to it and the rally in Louisiana. the first run was 286 miles from warehouse in Franklin, Tx. to Oklahoma home. I am still not real comfortable with the brakes, I have brakes I just want better. I am going to revisit that in the very near future.

Post a picture here of your isolation valve, it's in the drivers wheelwell on the frame.

There is a well documented problem with newish brass valves restricting the pressure to the rear brakes. If it is brass and older than ~3-4 years, it's probably this problem.

If it is steel/iron, observe whether the 'tit' on the front facing end of the valve moves out and in when depressing and releasing the brake pedal. If it moves, it's fine. Do not replace it. If it's frozen, then something is wrong.

You may also have a weak vacuum to the booster, or a weak booster.

You may also have some problems with the brakes, it's always a good idea to go through all your brakes and replace calipers, wheel cylinders, pads, shoes, hardware as needed and adjust the rear brakes correctly.
 
  • Like
Reactions: Blue
Post a picture here of your isolation valve, it's in the drivers wheelwell on the frame.

There is a well documented problem with newish brass valves restricting the pressure to the rear brakes. If it is brass and older than ~3-4 years, it's probably this problem.

If it is steel/iron, observe whether the 'tit' on the front facing end of the valve moves out and in when depressing and releasing the brake pedal. If it moves, it's fine. Do not replace it. If it's frozen, then something is wrong.

You may also have a weak vacuum to the booster, or a weak booster.

You may also have some problems with the brakes, it's always a good idea to go through all your brakes and replace calipers, wheel cylinders, pads, shoes, hardware as needed and adjust the rear brakes correctly.
Thank you Sir, just saw this, the proportioning valve is steel, and it appears to be correcting itself somewhat, I can now hear a rear brake squeel and it feels alot more formidable when applying the brakes.
 
  • Like
Reactions: tmsnyder
Thank you Sir, just saw this, the proportioning valve is steel, and it appears to be correcting itself somewhat, I can now hear a rear brake squeel and it feels alot more formidable when applying the brakes.

On the frontward end, there's a little tip that sticks out. Is that tip popping out / moving when you press the brake? Have a helper check, you need to remove the wheelwell liner to see it. If it's moving then it's working.

On my brother's coach, his was newer brass and not modified as per Lenzi, and he was getting almost zero braking from the rears. That part is critical and must be working in order to have even as good as stock brakes.
 
On the frontward end, there's a little tip that sticks out. Is that tip popping out / moving when you press the brake? Have a helper check, you need to remove the wheelwell liner to see it. If it's moving then it's working.

On my brother's coach, his was newer brass and not modified as per Lenzi, and he was getting almost zero braking from the rears. That part is critical and must be working in order to have even as good as stock brakes.
thank you I will do that test. It is too cold to do anything right now. Lol thank you so much for the information.