Stranded near Green Bay

[Nick Chapekis]

Drove about 400 miles from southeast Michigan to the UP yesterday with no issues, until tranny started downshifting to second on flat roads while
doing about 55 mph (3:42 final drive). Was able to get it to upshift by releasing accelerator, but then would downshift again when I tried to
accelerate. Checked vacuum lines and replaced modulator, but no change. Unfortunately I did not install the new modulator correctly and it started
leaking. Tried to reinstall, but too much fluid leaked out and I can no longer move the coach onto a curb to get under it. Can anyone provide
assistance or recommend a reliable, honest shop in the area that would be willing to actually work on it? I did locate a tow truck with a wheel lift
nearby, just not sure where to have it taken.

If I can get the modulator reinstalled, Manny recommended disconnecting the downshift solenoid, which if the culprit, would allow our vacation to
continue.

Thanks in advance.
--
Nick Chapekis
Ypsilanti, MI
78 Kingsley

 

[Ken B]

Hi Nick, Here is a second try. I lost the first try and I am typing a shortened second one.

You have what looks to me like a loss or weak vacuum to the modulator. I would be checking or replacing the two vacuum lines going the modulator.
Between those two lines is a thin steel tube. That tube can become obstructed with rust or carbon. When that happens you get no or reduced vacuum to
the modulator. On mine I had to remove the tube, apply 100 PSI shop air pressure to the modulator end and heat the engine end with acetylene or mapp
gas. IN your case (on the road) I would just get enough vacuum hose and make the whole run in new hose. If that works, You can fix it properly
later after you return home.

One last thought. Dan Gregg had a similar problem to yours. He said he thought it was the governor. I told him NO but he ignored me. He got a
rebuilt governor from Wally and fixed his problem. That ought to tell you that Ken does not always know what he is talking about.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[john r. lebetski]

Nick check the surrounding vacuum lines on top of engine. There was a 2” section of hose off a “T” on same circuit that had chaffed through on
friends coach. Easy fix.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[john r. lebetski]

Seems old vac hose has 2 fail modes. Hard and brittle like uncooked pasta or soft and mushy like over cooked pasta! Don’t feel bad Nick, I had same
issue after my Cinnabar engine install. Hose at modulator was soft and slightly too long so it would collapse or partly kink and restrict. GM vacuum
hose was not a simple spec. The architects design specs run about 4 pages as a .pdf. Not sure what materials they used in the 70s, but my friend
just reproduced the 80s stuff and had to source the polymer in Japan as not available here. Very specific.
--
John Lebetski
Woodstock, IL
77 Eleganza II