6.............. I was trying to find and =
identify the "power master" master cylinder =
setup. I didn't find anything that looked like the =
pictures or what I saw on Steve Ferguson's =
coach, but I did find a master cylinder setup =
with hydaulic lines running to the power =
steering pump and with no vacuum booster (at =
least that I could see). It was on an '85 =
Chevrolet Caprice Classic station wagon. Is this =
a variation of the power master or a different =
evolutionary strain, and is it something worth =
looking into for the GMC?
I too was looking for a "power master" master
cylinder.
Eventually though, due to concerns about lack
of back up system within the power master
(how do I stop the coach if the power master
failed) I went with a more conventional approach.
Modifications considered for the hydraulic
side of the brakes are all pointed in the same
direction.......provide more pressure on the
pads and shoes for the same pedal effort.
What I settled on was to go with the big calipers
up front and change from the 15/16" wheel
cylinders out back to the 1 1/16"
This provides approximately 30% more
pressure on the pads and shoes for the same
pedal effort.
I really needed to change the calipers and
wheel cylinders anyhow since they were
original. (26 year old brake fluid. Looked
like thick black coffee)The small calipers
and cylinders wouldn't have cost me much
(if any) less.
The concern not addressed by the wheel
cylinder change was how to stop if the coach
lost vaccumn boost.
To insure that there were no vacumn leaks
I shut of the coach and even 1 hour later the
brake pedal was still vacumn assisted.
That only provides a single application. To
provide vacumne in case of motor stall I
added the auxillary vaccumn pump
controlled by engine vacumn.
The above has provided me the security
I thought I needed your milage may differ.
As to the hydralic hoses running behind
the master cylinder what you were looking
at was a hydralic booster run by the power
steering pump. It replaces the vacumn
booster and performs the same function.
The hydralic booster is smaller and is
useful if the vacumne supply is poor or
nonexistent. I don't know of any other
advantages however the hydralic
booster would also quit providing boost
if the motor stalls.
Good luck in your hunt.
Regards
Gary Zingle
1973 GMC 26 foot
identify the "power master" master cylinder =
setup. I didn't find anything that looked like the =
pictures or what I saw on Steve Ferguson's =
coach, but I did find a master cylinder setup =
with hydaulic lines running to the power =
steering pump and with no vacuum booster (at =
least that I could see). It was on an '85 =
Chevrolet Caprice Classic station wagon. Is this =
a variation of the power master or a different =
evolutionary strain, and is it something worth =
looking into for the GMC?
I too was looking for a "power master" master
cylinder.
Eventually though, due to concerns about lack
of back up system within the power master
(how do I stop the coach if the power master
failed) I went with a more conventional approach.
Modifications considered for the hydraulic
side of the brakes are all pointed in the same
direction.......provide more pressure on the
pads and shoes for the same pedal effort.
What I settled on was to go with the big calipers
up front and change from the 15/16" wheel
cylinders out back to the 1 1/16"
This provides approximately 30% more
pressure on the pads and shoes for the same
pedal effort.
I really needed to change the calipers and
wheel cylinders anyhow since they were
original. (26 year old brake fluid. Looked
like thick black coffee)The small calipers
and cylinders wouldn't have cost me much
(if any) less.
The concern not addressed by the wheel
cylinder change was how to stop if the coach
lost vaccumn boost.
To insure that there were no vacumn leaks
I shut of the coach and even 1 hour later the
brake pedal was still vacumn assisted.
That only provides a single application. To
provide vacumne in case of motor stall I
added the auxillary vaccumn pump
controlled by engine vacumn.
The above has provided me the security
I thought I needed your milage may differ.
As to the hydralic hoses running behind
the master cylinder what you were looking
at was a hydralic booster run by the power
steering pump. It replaces the vacumn
booster and performs the same function.
The hydralic booster is smaller and is
useful if the vacumne supply is poor or
nonexistent. I don't know of any other
advantages however the hydralic
booster would also quit providing boost
if the motor stalls.
Good luck in your hunt.
Regards
Gary Zingle
1973 GMC 26 foot
