View Full Version : Hawk brakes

08-28-2005, 11:25 AM
Some of you may remember my posts when I was having difficulty getting good braking after installing a disc brake kit on my '62 Hawk.I received a great deal of helpful advice from many in this forum. I now have excellent brakes and the points below summarize what I learned and may help others.

a)My car was a 'power brake' Hawk (drum/drum) Had I installed Jim Turner's disc brake kit and utilized the existing single reservoir MC, things probably would have been fine and I could have kept using the booster.
b)When I opted to use a dual reservoir MC for safety along with Jim's mounting kit, I did not realize I would lose the booster.Had I known this, I may not have done it.
c) Some SDC members suggested using the booster on the front discs only but this was possibly dangerous. I did try it and it worked well but there was too much residual pressure holding the discs on and heating up (possibly a booster issue)
d)Standard braking was not good but the car was driveable. Stoplights , however, did make my heart thump.
e) As suggested, I finally obtained a 'standard brake pedal'. The shop manual said that power and standard brake pedals were different (true). It said that the linkages were the same but this is not true. The standard linkage is much shorter. I needed both the pedal and linkage as well as a longer return spring.
f) I discovered the Hawk had 2 pedal pivots on the frame. One was welded and closer to the MC. The other (to which the power brake pedal was attached) was a bolt on further along the frame. The standard brake pedal is different in shape, has a longer pedal section above the floor, and attaches to the second welded pivot closer to the MC. The bolt on pivot has to be removed to allow clearance.
g)The difference is dramatic! The standard brake pedal gives excellent braking with the discs and I assure anyone that the booster is not necessary.

Thanks to everyone for the help and patience while I worked through it.

Regards, John

'62 Hawk
'30 Chev Coach

08-28-2005, 05:57 PM
Hello fellow Canuck! What master cylinder did you end up selecting to match up with disk / drum combination? Did you also use separate residual valves for front and rear? 10# 2#.

How much pedal pressure is required to firmly apply the brakes now? Do you know how much line pressure you are getting to the front discs?


53 Starliner modified

08-28-2005, 07:07 PM
Hey Macstude! The MC was recommended by Jim Turner, 81-84 Jeep truck EIS #56193. It fit exactly with his adaptor kit into the space under the floor. I had to cut a bigger hole in the floor to access the MC for filling with brake fluid and make a new plate to cover the hole. The adaptor kit is high quality and necessary. A novice like myself could not have adapted another MC in this space without the kit.The kit includes the necessary #2 and #10 residual check valves as well as a proportioning valve for the rear brakes. You need to restrict the pressure to the rear brakes to allow them to keep the car straight instead of locking up.I do not know how much line pressure I am geting to the discs. With the previous power brake pedal it was not much and I couldn't lock them up. I needed to wear a diaper to drive. With the standard brake pedal installed, the breaking is not far off my '98 F150 pick-up.
Regards, John

'62 Hawk
'30 Chev Coach