don't measure off the snout because they might not all be the same
More Hydroboost ??
Thread Starter
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
More Hydroboost ??
OK, sometime back someone posted some hydroboost pics. I hyjacked one of them for my use and now that I am ready to mount mine I have a ?? or two.
Here is the ref pic I have
It shows the shaft length to be about 2 3/4" from the end of the snout of the HB Unit...ok
This is the same measurement on my HB Unit, as you can see they look a bit different
That looks way short to me, How much travel is needed for the brake shaft?
2 3/4" is the measurement from the mounting surface on the Vab Brake booster to the back of the shackle for the brake pin, but if I cut the shaft on my HB unit will that work? Will I have enough shaft left?
TIA
Danny
Here is the ref pic I have
It shows the shaft length to be about 2 3/4" from the end of the snout of the HB Unit...ok
This is the same measurement on my HB Unit, as you can see they look a bit different
That looks way short to me, How much travel is needed for the brake shaft?
2 3/4" is the measurement from the mounting surface on the Vab Brake booster to the back of the shackle for the brake pin, but if I cut the shaft on my HB unit will that work? Will I have enough shaft left?
TIA
Danny
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I suspect there maybe not enough throw on the new HB install for the full displacement of the master cyl.....I dunno, really....
so I hesitate to lend advice.....I need experiment with my car a bit more on that score, as I want the brake pedal lower to the floor, and the gas pedal too....but that means a longer pedal on the pull end...welding, and pulling the m/cyl off the HB, and checking throw, vs the throw on a m/cyl....to see if I can really cut the input shaft any further .....or bend/weld the pedal yet again...
decisions, decisions....such is hotrodding...find a solution, go back and rethink it again, and live with it ...think again...and....hell i'ts never over....
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Like I said, I will get some measurements tomorrow of the shaft at full travel and full rest. I will use a tape and two pics.
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
the top pic they are measuring from the end of the snout, on the second pic you are measuring from the mounting surface. I think this is causing some confusion. Because the two units are different I don't think you will be able to use the measurements from the top pic. I don't remember the measurements from when I did mine right off the top of my head. I measured from the mounting surface of the HB unit to the center line of the clevis pin.
Neal
Neal
Burning Brakes
Joined: Feb 2005
Posts: 1,235
Likes: 0
From: Mesa AZ
Thread Starter
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
the top pic they are measuring from the end of the snout, on the second pic you are measuring from the mounting surface. I think this is causing some confusion. Because the two units are different I don't think you will be able to use the measurements from the top pic. I don't remember the measurements from when I did mine right off the top of my head. I measured from the mounting surface of the HB unit to the center line of the clevis pin.
Neal
Neal
I ended up measuring from the outside of the firewall to the center of the clevis pin hole with the pedal all the way up and cut the shaft for that with about 1/2" adjustment on both sides of that. I think it will work, but will be a while before I can verify. I made a mount plate asuming (like an idiot) that the bolt pattern was square, it ain't.
So I got to make another plate tomorrow.
Matt, I ain't forgot about you.
I fabbed a pin for the unit, 3.45" I think was what was needed. Had to make 2 of those too. Ended up cutting one a little long and adjusted it down until the HB and MC just fit together without compressing the MC piston. Worked out pretty good. The plastic disk that keeps the pin centered in the HB Piston was inside the spring.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Some are square. Mine is, and many of the ones I deal in are. It depends what they came off of. some or nothing even close to square.
Can't wait to see pics of yours.
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Thread Starter
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
The hole pattern for the existing Vac booster is ot square. The HB unit only has the central mount nut.
SO your firewall bolt pattern is square? Mine is about 3/8" taller than wide.
SO your firewall bolt pattern is square? Mine is about 3/8" taller than wide.