Swapping out brake booster: How much PITA?

[69427]

Kicking around putting an '84 brake booster in the '69 (for a slight weight reduction), but I'm speculating getting at the bolts won't be fun. Anyone pulled their booster out and can offer up some tips on reducing the headache factor?

Thanks a bunch.

 

[mrvette]

I dunno Mike, Had that dash in/out of there so many times, think it was a dick on a dawg.......

My suggestion is to modify that damn lightbulb install wiring so to make just one plug for the whole mess.....

But other guys say to remove the seat and lay back with a 3/8 rat shit and get at the top bolts.....

years ago I modified the dash panel for ease of removal, and so drop the whole thing in/out in about 20 minits either way.....obviously have to drop the wheel too.....just the dash mounts......

my last go round, I forgot to plug in the speedo....I was SO happy.....:shocking::crap:
All honesty, I suspect one has to be a kid to get at them top bolts with the speedo panel in place.....:beer::beer:

 

[denpo]

Remove the seat and the T-top, your back on the floor, foot in the air and head under the dash.
A ratchet wrench with extensions and u-joint did the job for me.

 

[JPhil]

Remove the seat and the T-top, your back on the floor, foot in the air and head under the dash.
A ratchet wrench with extensions and u-joint did the job for me.

And duct tape all the ratchet extensions & u-joint so they are stiffer and don't come apart. I used a 1/2" drive socket & u-joint, then 3/8" extensions. It was deep enough to work but not as deep as a 3/8" drive deep socket, which helped.

I removed the vent duct & lower steering column cover too.

And secure the door open so it doesn't swing shut and latch while you're wedged under there. Ask me how I know about that one.

It really wasn't nearly as bad as people make it out to be. On my car at least.

 

[Red77]

Not Corvette related, but brake booster related: back when I was turning wrenches for a living, the best way to make sure I had a brake booster job waiting for me after lunch was to eat a huge BBQ stuffed baked potato at lunch. Like clock work, full belly, then needing to crawl under the dash to pull the fasteners off the firewall. My advice, do this job BEFORE eating...

 

[SuperBuickGuy]

Remove the seat and the T-top, your back on the floor, foot in the air and head under the dash.
A ratchet wrench with extensions and u-joint did the job for me.

Did your Corvette buy you dinner afterwards? :mobeer:

 

[69427]

I appreciate all the input. :thumbs:

Any worthwhile benefit to pulling the steering column out first?

 

[mrvette]

I appreciate all the input. :thumbs:

Any worthwhile benefit to pulling the steering column out first?

NO, I don't think so, I just loosen the firewall bolts a tad and remove the upper bolts, and let it flop....if it's a TT wheel put in down position and remove tach/speedo dash.....maybe pull the two bolts on the steering coupling....

I just sat on the seat and reached forward to get at it during the HB install, years ago, but today :gurney::crap:

 

[69427]

Got most of the adapter details worked out, but I'm still working on the attachment of the booster pushrod to the brake pedal arm. The C3 pushrod is a (two pronged) clevis that (I assume) just slips over the pedal arm. The C4 pushrod is kind of the complementary shape, in that it has a single flat piece on the end. I need to do a bit more research to see if the C4 pushrod just attaches (in single shear) to one side of the pedal arm, which would require that I offset the booster a touch (in the '69) to position the pushrod on one side of the pedal arm.

I need to crawl under the dash of the '84 tomorrow to see if I can get a good look at the brake pedal arm area.

 

[COLE SWEAT]

Why not go with a hydraboost

 

[69427]

Why not go with a hydraboost

The point of the swap is weight reduction, not weight increase.

 

[mrvette]

Why not go with a hydraboost

The point of the swap is weight reduction, not weight increase.

I did not weight each piece and do the math, BUT, just by the heft/hand weight of the units,....my aluminum master cyl from Pirate Jack Racing.....vs the stock m/cyl and the different weight from the HB to the old suck system....I figgered it was within a short count of lbs. differential.....I figgered an even trade.....

just a NON scientific observation over the years.....

:hi:

 

[JPhil]

OEM vacuum booster can weighs 8 pounds, hydraboost unit weighs 15 pounds, 16+ with hoses & fittings.

 

[69427]

Why not go with a hydraboost

The point of the swap is weight reduction, not weight increase.

I did not weight each piece and do the math, BUT, just by the heft/hand weight of the units,....my aluminum master cyl from Pirate Jack Racing.....vs the stock m/cyl and the different weight from the HB to the old suck system....I figgered it was within a short count of lbs. differential.....I figgered an even trade.....

just a NON scientific observation over the years.....

:hi:

I'm currently using a C5 master cylinder. It's about 7 pounds lighter than the stock C3 part.

 

[69427]

Picked up an '84 booster (and master cylinder) this week. Booster looks to be about 4#, half the weight of the C3 booster. A booster to firewall adapter looks to be pretty easy to fabricate. I'm still working out some options on how to convert the C4 booster pushrod to hook up to the brake pedal arm like the C3 part does.