GMC Motorhome Digest V3 #218

chuck will

New member
Nov 18, 1997
479
0
0
>>
>> Stockton to the border in 24 hours and then the time went
>> to h... courtesy Canadian Customs.
Good Evening! Memorial Day week-end 1978, I rode my Harley from the
Mexican border (Tijuanna) to the Canadian border, (Vancover) leaving Mexico
at midnight, Friday or Really 0001 Saturday AM arrived in Vancover 3PM
Monday afternoon. Stopped at a KOA in Klamoth Falls for a few hours of
rest. That was 1440 miles actual first stop other than for gas etc. I
don't know if they still do this or not. It was called the Three Flags
Classic in those fdays. Chuck
 
That was 1440 miles actual first stop other than for gas etc. (On a
Harley in 1978)

Chuck, that was 21 years ago! Could you/ would you do it today??

Dave Greenberg
Seasons Greetings To All!
 
Justin
I am with Emery in that I think it is internal leaks in master cylinder.
The fact that you have a Power Master instead of Vacuum Booster should
make no difference in symptoms/repair. The Combination Valve (NOT
PROPORTION VALVE) is low suspect since any internal leaks would aid in
making the pressure equal on both sides of the piston. An imbalance
pressure is required to move the piston to activate the Brake Lite. It's
a good preventive maintenance step to replace the Combination Valve with
the Brass One (GM # 25509419, Delco number unknown) before you need it.
A test that I have use to verify master cylinder problem is to start
engine & apply light pressure to brake peddle & note if it slowly goes to
floor. If so, then internal master cylinder leaks exist. The fact that
a master cylinder is new does not mean it's good. Must be proven first
!!!!
OBTW I have found that Wagner Master Cylinder P/N F79821 is
suitable/perfect for "73 thru '78 with Lifetime warranty. New cost
about $60 wholesale.

Duane Simmons