TTT

Looks like I may do this upgrade since my stock dual booster died.

Howdy all!
I get to pay some "Stupid Tax." I power washed the engine compartment 3 weeks ago before I put the engine back in the car after a "refresh." I must have got some water in the booster as it is failing (pancake style). That having been said, I have never been truly happy with the brakes. The rear is a Ford 9in with disc brakes that I bought from Quick Performance. I have bypassed the stock proportioning valve for one I got from them. I was doing some research on the difference between the 9in dual and my 12 inch single booster when I found this thread. Thanks! I figure, all else being equal, considering I have to replace this thing anyway, I just as well consider this an upgrade??

So, I went DIRECTLY to RockAuto and looked up a booster for a 1990 Caprice with a v8. https://www.rockauto.com/en/catalog...&+wheel+hub,power+brake+booster,1884

I have 3 x questions. I plan on re-using my current Master Cyl (factory style for a 1979 Monte Carlo). If it matters, this car was originally a 231 V6 car.

1) Do I want one with or without the Vacuum Switch Port? Was GUESSING without, but was not 100% sure.
2) Does anybody know if these boosters come with the new pin? And just to clarify, I still use this pin with the Caprice booster and the Monte Carlo Master Cyl?
3) This does not look TOO much thicker than the pancake style I'm removing, so I'm assuming the brake lines won't need and modifications as they leave the Master Cyl?

Thanks again!
Russ

Russ,
1) If your original 12" single diaphragm booster has the vacuum switch port, then order one with the port. The images in my original post show the port present (in an 86 SS).
2) Yes, the booster will come with a new pin that is matched in length to that specific new booster. Do not use the pin from the old booster.
3) While the master cylinder is positioned slightly more forward due to the increased thickness of the booster, the brake lines won't need to be modified. They should have sufficient flex and slack to accommodate the slight re-positioning.

Good luck!

PaulC

Thanks for the super quick reply!



Does the vacuum switch port screw into the intake manifold and look like this:



If so, I don't have that. Mine comes out of that elbow on the booster and goes to the port on the back of the carburetor.



Thanks for confirming that!


Thanks again!

Reading this, I don't see a down side to putting this booster on my car.

How did I get stuff done before these forums existed? LOL!

THANKS!

Russ,
The TVS (Thermal Vacuum Switch) image you posted.. that goes on the thermostat housing at the front of the engine. To my knowledge it's not associated with the brake booster. The vacuum port I think they're talking about is mounted on the booster itself. If you look back at the first post, the image with the two boosters sitting on the ground next to one another... the vacuum port is in the upper left of each booster at about the 10 o'clock position. If your original booster has this port, then you want a replacement booster with the vacuum switch port.

PaulC

Paul, thanks for the info. I googled the term "Vacuum switch port" to see if I could figure it out and Google lied to me! ;-)

I just went out to the shop and snapped these pics of the outgoing booster.







I went back to Rock auto and looked at what they have listed for my car originally. That was this:

https://www.rockauto.com/en/moreinfo.php?pk=259020&cc=1055977&jsn=10579

I don't see any mention of a vacuum switch port on the original style for my car that the Caprice ones mention. Can you tell from my pictures if mine has the vacuum switch port? The one I ordered did NOT have one. I can always return it if needed.

Is the little elbow coming out of the booster, that goes to the back of the carb, the switch in question?

I ordered this one:
https://www.rockauto.com/en/moreinfo.php?pk=2961087&cc=1037203&jsn=1


Thanks again!

I think you're good to go with the booster you ordered. Let us know how it went and show it off with some pics!

PaulC

The booster I ordered from Rockauto did not come with a new mounting gasket, so I had to order one from Mike's Montes. Its not a part most places bother to carry. The old 9 in dual booster in my Regal lacks the vacuum port.

One more concern as I look at the pictures of my stock booster. The paint below the booster is coming off. I'm wondering if the Master cylinder isn't leaking out the back as well.



I've spent the last hour or two (time gets away from me) reading about upgrading the master cylinder as well. Being a 1979 Monte, Mine USED to have the proportioning valve under the floorboard. I got a new valve with a dial when I upgraded to the rear discs several years back. IF the master cylinder is leaking, should I also get a master cylinder from a 1990 Caprice as well? As the stock style from mine is set up for rear drum brakes.

Another concern reading posts here is the threads. Will the 1990 master cylinder have the same threads as my current brake lines? I can EASILY knock this out over the weekend if I get the parts in line now. My 1990 Caprice booster will be in on Friday.

Thanks again!

I assume you mean the gasket between the booster and the firewall? Did your RockAuto booster come with the "plunger" from the booster to the Master Cylinder?

Yesterday I picked up my Master Cylinder for a 1990 Caprice:
https://shop.advanceautoparts.com/p...-10-1870/5352363-P?searchTerm=master+cyl

Was only $25. Even if the master Cylinder ISN'T leaking causing the paint on the current booster to come off, having a master cylinder that sends the PROPER amount of brake fluid to the upgraded rear discs CAN'T be a bad thing. I'm excited to see what all I've been missing all these years with my back brakes!

My Booster should be in today. Which will give me a matched booster and Master Cylinder. (for a 1990 Caprice) I can get it all installed over the weekend.

I used booster off 98 was pretty different then the 78 g body I transfered it to .I has to deal with the longer pedal push rod the pushrod pin size was bigger on the s10 and the 4 bolt studs were about 1/16" closer. I DID GET THE THING TO WORK AND GOOD. I had to make pipe spacers to let booster ahead some.I had to file the holed in firewall.I had to make a bushing to fit to the smaller pedal pin...I had to grind the side of the push clevis hole thinner to get the washer and pin back on.and use the old plastic elbow off the monte I still need ti fill in the space between the booster and firewall were I have spacers for floor level .you have to bend the brake switch bracket too good luck its way better but too much work