When I began the installation of this kit I immediately found problems with the mounting hardware supplied with it.
The bolts supplied were about
1¼" short due to the spacers used to add clearance for the clutch master assembly. This adjustment also caused the dust boot supplied to be 1¼"
short also. Since the booster/master is the same as used on all models, I wondered if anyone had actually applied this kit to a '60 thru '62 chevy
truck with hydraulic clutch.
Then I got to the clutch.
The bracket and hardware supplied for the clutch assembly are well made. The clutch master is by Wilwood. The problems began after installation
when I
attempted to disengage the clutch for the first time. What a bear! The pedal from hell and no disengagement of the clutch. After going over
the system as provided by Master Power Brakes, I found that they had supplied the kit with a ¾" bore, 1" stroke master. The OEM master cylinder
bore is 11/8", 1" stroke.
Since the slave cylinder is 1" there is virtually no way for this setup to provide the hydraulics needed to operate the clutch assembly. I called
Wilwood to run this by them and they agreed. I called Master Power Brakes to request a proper replacement master cylinder and was told that the
system works as is and that was it. I was on my own and customer service has never contacted me since. I then purchased the proper size master
from Wilwood and was able to disengage the clutch.
Note: Since this time I have noticed Master Power has switched to the proper sized cylinder.
The next problem is how this kit (BM1750) is installed at the pedal arm. The original push rod from pedal arm to master is at 1" below the pivot
point giving 14" of lever from the point of foot pressure to the push rod. The Master Power Brake attaches the push rod 5" below the pivot point
giving 10" of lever. The point here is, when decreasing the leverage from a fulcrum point there is more pressure needed to move the load (the
load in this instance is the clutch assembly). The kit changes the leverage geometry employed to operate the clutch. Further, they supply a 5/16"ball
type clevis end on 5/16" rod (OEM is 3/8"). The clevis attaches to the side of the pedal arm through a 3/8" hole leaving considerable slop in the leverage
assembly. With the pressures present and the off center attachment of the rod to the pedal arm, the 5/16" rod bent. I applied a fork style 3/8" clevis
on a 3/8" rod and immediately felt some relief from the pedal assembly.
I can not believe Master Power Brakes ever installed this kit into a '60 thru '62 chevy truck with hydraulic clutch. Too many wrong parts and a major
snafu in the clutch master assembly is evidence of this. The placement of the rod to the pedal arm is really the only place to apply it because of the
framework under the dash. Had I realized this fact I would have opted to install mechanical clutch linkage. The BM1750 kit is $200 more than the
BM1754 which fits all chevy trucks to '72. Master Power Brakes refuses to accept some responsibility and it cost me another $80 to purchase the
proper
bore master from Wilwood and another $20 to handle their hardware misques. Too much time, money and effort was involved in re-engineering
this
kit to make it worth while.
I believe this kit was not properly tested prior to marketing and until Master Power Brakes improves their customer service I will not recommend them
to any body asking my opinion. There are many other quality brake system suppliers in the aftermarket industry to choose from.
Spring 2005
The issues with this kit did not end with my earlier observations and issues.
The truck I installed the kit on is used for work, i.e. firewood, pulling brush, fencing and getting out off road for exploration, so the mileage is low (less
than 2000 miles since I installed the engine and brake/clutch kit.) I was out in some rugged terrain with my wife on a Saturday when the clutch failed to
disengage. Upon opening the hood I could see right off that the bracket failed (weakened) and had swung out to about a 45 degree angle from the
firewall. The bracket is merely bent on a brake to achieve a 90 degree angle - no bracing or reinforcement. For the amount of pressure being put onto
this part I am surprised there haven't been more complaints about this issue.
Fortunately I was able to resolve the situation in the field by disassembling the bracket assembly, straightening it out, reinstalling the bracket and cylinder,
then wedging my iron chaulk blocks between the fender wall and the clutch hydralic master to keep it stable enough to get back home. I'm not a design
engineer but in my own fabrication capacity I would still have given some deeper thought to the type of material and the structural strength (reinforcement)
necessary to handle the pressure put on this assembly. I would also have tested it out before I attempted to sell this kit.
I'm not impressed with Master Power Brakes or this kit. On the plus side the brakes operate great but still, 1 out of 5 is only 20% ...that's just shitty.
~Vern
Ironhorse Mechanical
Spring 2011