front brake upgrade questions

[T-Type Mike]

Guys I've been reading up on upgrades for the front brakes. My T-type needs calipers and rotors. I think forsure I will be going with 12" Rotors off a 1LE and pay extra for the cross drilled for "That look". So on Gnttype.org they say I will need Caprice Calipers and spindles as well as tubular control arms. Now are there any others out there who have done this route and are happy?? I am curious how well this will work with the Powermaster set-up. And last are there any downsides. Any other options that may help out would be enormously appreciated, Thanks in advance, Mike

 

[T-Type Mike]

Also this might be dumb, but when they say tubular control arms needed. Are they refering to a G body arm or B body control arm? Thanks again,

 

[bruce]

Originally posted by T-Type Mike
Guys I've been reading up on upgrades for the front brakes. My T-type needs calipers and rotors. I think forsure I will be going with 12" Rotors off a 1LE and pay extra for the cross drilled for "That look". So on Gnttype.org they say I will need Caprice Calipers and spindles as well as tubular control arms. Now are there any others out there who have done this route and are happy?? I am curious how well this will work with the Powermaster set-up. And last are there any downsides. Any other options that may help out would be enormously appreciated, Thanks in advance, Mike

I've got the 12" setup.
Love it. nothing like being able to drop out of worp speed, and know you can actually stop.

I have the Hotchkis Upper Arms. Robert Adams is selling a kit with more affordable arms. You'll have to google for hi address.

The power master leaves alot to be desired, IMO.

With vac, or manual you have much better pedal feed back, again IMO.

 

[T-Type Mike]

Thanks Bruce, Now would you recommend upgrading to vaccum brakes at this time? Thanks

 

[motorhead]

Originally posted by T-Type Mike
Thanks Bruce, Now would you recommend upgrading to vaccum brakes at this time? Thanks

I would.

I'll be going to vac. next year, using a 7/8" bore B-body MC and a dual diaphram booster.

I have the Robert Adams set up on my 87 T. Very nice.

Skip the X-drilled rotors, unless you are a ricer you won't find any performance gains in them. In fact you will be reducing swept area and thus nulling the point in going to 12" rotors. Get the point?

As for the PowerMaster and the 12" swap...
The pedal is really rather soft... it drops off really quickly with the B-body calipers (bigger void to fill)... the PM sucks for this do to volume capacity of the res. Takes some getting used to... I rebled the brakes 3 times because I thought something was wrong.

HTH,

 

[Silver 6]

I am planning this as a future project also and have started collecting the parts. I found the slotted 1LE rotors on ebay for $149 the pair. I found the loaded rebuilt "B" body calipers the on ebay also for $54 the pair. Now if someone would post some tubular A arms, I'd be another step closer.

I have seen other posts like Michael's that said the powermaster was not up to the job. I always wonder why it wouldn't be. I picked up my spare PM from a "B" body Buick wagon. They used the 12" brakes on the front and the large 11" drums on the rear. If the PM handles the load for the larger wagon, why can't it keep up in the lighter Regal with the same brakes?

Could it be the placement of the push rod on the brake pedal? I know it changes from the vacuum to the PM to change the ratio of inches of pedal movement to inches of rod movement. Is that diffferent on the wagons to provide more leverage?

 

[Nick Micale]

Re: Re: front brake upgrade questions

Originally posted by bruce
I've got the 12" setup.
Love it. nothing like being able to drop out of worp speed, and know you can actually stop.
.............With vac, or manual you have much better pedal feed back, again IMO.

Bruce, on gnttype you said my car with manual brakes must have something wrong with it like "master cylinder sizing or wrong pedal".

Are you comparing it to yours with 12" rotors and whatever?????

 

[GNVAIR]

If you do the b body brakes with the vac set up, I would HIGHLY recommend installing the 1 1/8" bore b body master cylinder as well. The stock g body sized master cylinder bore is too small and wont supply sufficient volume to give a good pedal. I have done this conversion on about 4 different cars and can attest that it makes a huge difference in stopping power. But you have to make sure you match the correct pieces. The Power master is barely adequate IMHO with stock brakes. I think it would be really stretching it with the b body stuff since the b body caliper pistons are significantly larger than the stock g body stuff.

 

[AsphaltAnihil8r]

http://gparts.freeyellow.com/

Look in the brakes section,,,

I have his arms and "so far so good"

 

[turboman38]

GNVAIR

I just pulled a vacuum setup off a Cutlass in a junkyard. Can I use the "bigger bore" master cylinder with a stock G-body vacuum booster? If so does anything else have to change?

 

[AsphaltAnihil8r]

Originally posted by turboman38
GNVAIR

I just pulled a vacuum setup off a Cutlass in a junkyard. Can I use the "bigger bore" master cylinder with a stock G-body vacuum booster? If so does anything else have to change?

Did you get the pedal??you need that also

 

[turboman38]

Yes, I did pull the pedal. My question is: Can I use a bigger bore Master Cylinder with a stock G-body vacuum booster? If so are there any other changes I need to make? If I can do this then what master cylinder do I ask for at the parts store? B-body is a Chevy Caprice correct? So If I ask for a master cylinder for a 1986 Caprice will it work with my stock G-body vacuum booster?

 

[GNVAIR]

Yes, you can use the g body vac booster with the b body master cylinder. I used a master cylinder spec'd out for an 86 Caprice Wagon. Just maje sure you swap the plastic reservoirs. You will need the plastic reservoir from a g body vac master cylinder since the b body one wont clear the hood.
Oh yeah, make sure you get the brake pedal too.

 

[choppers4life]

i would check into a baer track kit. we installed a 13" set in the front of my mustang for something like $1300. they have a ton of options, i would really recommend this

 

[turboman38]

Two more questions:

What advantage does the larger B-body master cylinder offer over a stock G-body master cylinder? Will It have more stopping power or hold more boost at the line?

Is the rod that fits in the front of the vacuum booster (the one that pushs the master cylinder in) different from a b-body to a g-body? In other words which rod should I use?

 

[Silver 6]

Lee J.

I believe you have touched on why I think the PM "should" work with the larger brakes.

If the PM was originally designed for the "B" bodies with the larger brakes it would have a larger bore MC than if it were designed for the "G" bodies with the smaller brakes. This would mean more line volume, but less line pressure. On the "G" bodies the pump provides the needed boost for good line pressure. But when the pump fails your leg is just not up to the task.

I would think the PM is actually a better match for the big brakes.

 

[motorhead]

Originally posted by GNVAIR
If you do the b body brakes with the vac set up, I would HIGHLY recommend installing the 1 1/8" bore b body master cylinder as well. The stock g body sized master cylinder bore is too small and wont supply sufficient volume to give a good pedal. I have done this conversion on about 4 different cars and can attest that it makes a huge difference in stopping power. But you have to make sure you match the correct pieces. The Power master is barely adequate IMHO with stock brakes. I think it would be really stretching it with the b body stuff since the b body caliper pistons are significantly larger than the stock g body stuff.

Ooops... that is what I meant. 1-1/8" MC. D'oh!

 

[GNVAIR]

Originally posted by Silver 6
Lee J.

I believe you have touched on why I think the PM "should" work with the larger brakes.

If the PM was originally designed for the "B" bodies with the larger brakes it would have a larger bore MC than if it were designed for the "G" bodies with the smaller brakes. This would mean more line volume, but less line pressure. On the "G" bodies the pump provides the needed boost for good line pressure. But when the pump fails your leg is just not up to the task.

I would think the PM is actually a better match for the big brakes.

Unfortunately it just isnt that easy. The PM has barely enough assist for the stock rotors and calipers. It is terrible in the b bodies. Have you ever driven a b body wagon with them? Its down right scary!
The PM also needs more leverage on the pedal. The pivot point is higher up on the pedal; much like a car with manual brakes would have.
I couldnt believe the difference in stopping power and pedal feel when I replaced the PM in my GN with its stock brakes. Before, they reminded me of trying to stop with manual brakes. As a matter of fact, every single 85-87 TR I have driven with the PM felt the same way. They just did not feel like they had a lot of assist or grab to them. When I switched to the vac brakes I had to get used to not trying to stop the car with as much pedal effort. You could seriously put someone through the windshield.
When I did my first b body swap and tried to stop the car, it just felt like I couldnt get a good pedal. They wouldnt grab until the bottom of the pedal travel and this was after properly bleeding them. I switched to the larger b body master cylinder and it solved it. Actually, the difference in stopping power is tremendous. The pedal feels firmer than it ever did with the PM or vac set up on the stock brakes. The travel on the pedal is minimal and the modulation is good as well. My recommendation is to spent the extra money and get a vac set up. I know all my local TR buddies have converted and not one of us have had any problems. The only people IMHO that should keep their PM are the purists

 

[Silver 6]

OK Lee. You have me coming around. I have to admit the brakes on my daughter's 83 Bonnie were always better on feel than the ones in my T with the PM.

 

[GNVAIR]

I wouldn't recommend converting to anyone that doesnt want to. But if performance driving is your thing, then I would highly recommend not only the b body upgrade, but also the vac conversion. Neither of which are irreversible modifications if you are worried about returning the car to stock someday.
Just be aware that the stock steel 86-87 GN rims wont clear, but the aluminum 84-85 GN and 86-87 T/T Type rims will.
I have never tried it with the 83-85 aluminum T Type rims.